Instructions for Use of Service Manual

Model Identification Unit Version with a different numeral is specific in-

formation for the title vehicle.
I n most sections of this manual, the individual models
are identified by the chassis type instead of the model Depending on the unit installed in the vehicle, the
designation. The chassis type designations are the first numeral for the unit version may vary in the different
six digits of the chassis number (see page 005/2). groups.

For example, sales designation model 280 E is chassis Example:

type 123.033.
32 - 120 Checking shock absorber
I n some instances, only the first three digits (123) will
be referred to. I n this case, this section applies to all
vehicles of this particular chassis type. Job description No.
Job No.
Group No.
Location of Specific Repair lnstructions

Data, adjusting values, processing dimensions, tight-

Locate main component group in Group Index. The
ening torques and tools are listed at the beginning of
group number is listed in the upper outside corner of
each Section.
each page within the group.

All the dimensions are in millimeters (rnrn), provided

Check group contents, first page of each group, for
no other unit of measure i s used.
the exact job description required. The job numbers,
succeeded by page numbers within each group are
The indicated part numbers are serving exclusively
listed in the lower portion of the individual pages.
for identification and better differentiation of indivi-
dual versions. When ordering spare parts, the part
Unit Version 0 in the various Groups is general infor-
numbers must always be taken from the respective
mation applicable to the pertinent unit.
spare parts literature.
 Model and Unit Survey

Model Model Year Chassis Engine

From To TYP@ TYpe
 Technical data

Engine

Model

Operation I Four-stroke diesel engine

Stroke mmlin. 1 1
92.413.64 92.413.64

Total eff. piston

displacement

Compression ratio

Firing order 1-3-4-2 1-24-5-3

--

Max. engine rpm (no load) 4350 5400 5200 5100

Engine output SAE net bhplrpm 5714200 6214000 6514200 7714000

Max. torque SAE net Ib.ft./rpm

Oil cooling Air-oil cooler

Water circulation pump, thermostat with by -pass

Cooling
line, fan with viscous coupling, finned tube radiator

Lubrication I Forced oil circulation via gear-type oil pump

-- - - -

Oil filter Combination full-flow by-pass filter

Air filter I Oil bath Paper cartridge

Up to model year 1 9 7 8
Starting model year 1 9 7 9
00-1 10 Removal and installation of engine (oil quantity)

Recommended viscosity grades

according t o SAE
at constant ambient temperatures

1) SAE 4 0 o i l can be used a& constant ambient

temperatures above + 3 0 C (+86O F ) .

Oil quantity in liters (for approved engine oils refer to "Service product specifications")

Engine

Tota\ quantity for refilling 6,5l) 7,01

)

) 0 . 5 l ~ t e r smore f o r models w i t h air-cooled o i l coolers

Tightening torques

Oil drain plug in oil pan

---
Fastening bolt for lower part of oil filter (type 1 15.1) 40-45 (4.0-4.5)

Center bolt and nuts for oil filter cover (type 123.1) 20-25 (2.0-2.5)

Bolts for engine bearer at engine mount front - 12

M 70 (7
(type 123.1) M 10 40 (4)

Nuts for engine stop on crossmember (type 1 15.1) 90 (9)

-
Adjusting screw for front engine stop (type 123.1) 130 (13)

type 115.1 30 -
(3)-
Adjusting screw for rear engine mount
type 123.1 40 (4)

Special tools

Torque wrench handle 20-1 00 Nm (2-10 kpm) 001 589 35 21 00

- - -
Torque wrench handle 50-200 Nm (5-20 kpm) 001 589 44 21 00

Ratchet for torque wrench handle 001 589 42 09 00

' 3?!04-7115
Radiator cap with hose for
leakage test

=9
Stud-endlbox-end wrench 14 x 17 mm . .k 2
000 589 24 07 00

Oil removal syringe

Commercially available tool

e. g. Backer, 5630 Remscheid,

Engine hoist (1.5 t lifting capacity)
order No. 31 78

Removal

1 On type 123.1, move engine hood to 90' position

and latch left-hand locking lever (arrow).

2 Fully drain coolant.

3 Remove radiator.

4 On engine models 61 5 and 61 6, remove upper part

of air filter. On engine model 617 in general and on
engine models 61 5, 616 featuring injection pumps with
mechanical governors, remove air filter.

5 On models with air-conditioner, detach A/C com-

pressor together with bracket and connected pipes,
and then put down on one side.

Remember to empty air-conditioner if A/C com-

pressor is removed (83-516 ) .

6 On models with level control, detach delivery oil

pump together with connected lines. To do so, simply
release bolts (arrows).
7 Draw oil out of power steering pump reservoir and
disconnect hoses.

8 Unhook control linkage.

9 Disconnect all coolant, vacuum, oil, fuel and elec-

tric lines which lead to engine.

10 On uprated engines, remove longitudinal control

shaft. T o do so, unhook control rods, withdraw
retaining ring (arrow) and force longitudinal control
shaft backward.

11 On types 1 15.1 17, 123.105/130/150 and 123.102/

103/120/123/126/183 featuring automatic trans-
mission, unscrew engine shock absorbers. On type
11 5.1 14, release engine shock absorbers from body-
work and force out toward engine.

T y p e 11 5.1 1 4
Englne shock absorber left (straight-ahead)

T y p e 115.114
Englne shock absorber right (straight-ahead)

T y p e 11 5.1 17
 Types 123.102/103/120/12311261183
featuring automatic transmissions

Types 123.105/130/150/190

12 On types 115.1101115and 1 23.1, unscrew engine

stop.

On types 115.1101115, it is then necessary to unscrew

self-locking nut (32) and withdraw adjusting screw.

Types 1 15.1 101115

On type 123.1 (with the exception of types 123.105/

13011501190 featuring two engine shock absorbers),
lift up retainer (30) and swivel away to one side.
Unscrew adjusting screw ( 31) .

13 Unscrew exhaust at exhaust manifold and at lateral

support on transmission.

Type 123.1
14 On types 115.11011 151117 featuring automatic
transmissions, unscrew steering shock absorber one
side (arrow) and turn away.

15 On type 123.1, unscrew engine bearer bolts at

engine mount front, doing so from below. On type
115.1, work from above.

T y p e 123.1

16 Unscrew propeller shaft at transmission.

17 Release all connections and shift rods at trans-

mission.

18 Remove rear engine bearer with engine mount.

19 Attach engine hoist ropes to suspension lugs.

For engines in type 115.1, bolt one suspension lug to

cylinder head at front. Use may be made of the sus-
pension lug fitted to engines in type 123.1.

The rear suspension lug on engines in type 11 5.1 is

located on the intermediate flange.
For engine 61 7 in type 11 5.1, wrap the rear rope around
engine.

Front suspension lug, type 123.1

 Rear suspension lug, type 123.1

20 Lift engine and transmission up and out at about

45".

View showing engine 61 7 in type 1 1 5.1

lnstallation

Caution:
When installing a new engine as a result of bearing
failure, flush out the oil cooler, oil hoses, and clean
oil filter housing.

21 Check engine mounts, engine shock absorbers, oil

and fuel hoses, replacing if necessary.

22 Prior to attaching manual transmission to flange,

check deep-groove ball bearing in crankshaft as well
as clutch throwout unit, replacing if necessary.

23 Install and connect engine.

24 Attach and adjust propeller shaft (41-020).

25 Adjust engine stop (00-220).

26 Check all drain plugs for firm fit.

27 Fill with oils and coolant (20- 010).

28 Pressure-test cooling system, using pressure tester.

Check coolant for antifreeze (20- 010).

29 Clean air filter element, replacing if necessary.

30 Adjust idle speed (07.1-050).

00-1 15 Checking compression pressure

Testing data in bar positive (atii) for hot engine

Compression pressure normal 22-24

Minimum compression pressure ca. 15

Permissible difference between any two cylinders max. 3

Tightening torques Nm (kpm)

- - - - - - -

Cap nuts of injection lines 25 (2.5)

-- ----
Injection nozzles in precombustion chambers 70-80 (7-8)

Special tools
----------

Remote starter switch (individual

component of compression pressure
recorder 001 589 46 21 00)

Note

Check compression pressure at 80 O C coolant tempera-

ture. The compression pressure can be checked through
the spark plug hole or the precombustion chambers. I f
engine fails to reach minimum combustion pressure,
check cylinders for leakage (00-120).
Checking

1 Unscrew all glow plugs or injection nozzles.

2 Connect remote starter to terminals 30 and 50 on

starter.

Positive battery terminal can be used in place of

terminal 30.

3 With transmission in neutral, crank engine several

times to eject carbon deposits.

Caution:
On engines featuring injection pumps with mechanical
governors, first move stop lever (stop) in direction of
engine so that injection pump will not inject fuel.

4 Screw connector into glow plug hole or precombustion

chamber of each cylinder in turn.

5 Connect compression pressure recorder.

6 To check pressure, crank engine by 8 revolutions

while using full throttle.

Compression pressure recorder connected to

glow plug hole.

On engine models 61 7 in general and on models 61 5,

616 featuring injection pumps with mechanical
governors, do not use full throttle because these en-
gines do not have throttle valves.

7 Prior to inserting the injection nozzles, f i t new

nozzle plates.

Compression pressure recorder connected to

precombustion chamber
00-120 Checking cylinders for leakage

Data

Total pressure loss max. 25 %

at valves and cylinder head gasket max. 10 %
at pistons and piston rings max. 20 %

Special tool

Socket 27 mm
to crank engine

Commercially available tool

e.g. Bosch, E F A W 210 A

Cylinder leakage tester
SUN, CLT 228

Checking

1 Warm up engine to operating temperature.

2 Unscrew glow plugs.

3 On engine models 615 and 616 featuring injection

pumps with pneumatic governors, detach rubber
gaiter at throttle body and set throttle valve to full
delivery.

On engines featuring injection pumps with mechanical

governors, detach air filter.

4 Remove oil filler cap.

5 Remove radiator cap and top up coolant.

6 Screw connector into glow plug hole of No. 1

cylinder.
7 Set piston of No. 1 cylinder t o ignition TDC.

To do so, turn engine at crankshaft, using tool com-

bination.

8 Connect cylinder leakage tester to air system

Cal ibrate tester.

9 Screw tester connecting hose to connector.

Make sure that crankshaft does not turn.

10 Note pressure loss on tester.

11 Listen to check whether pressure escapes through

intake pipe, exhaust, oil filler cap, glow plug hole of
adjacent cylinder or radiator cap.

12 Check all cylinders in firing order.

Note: The reading will be falsified if the piston ring

gaps of a particular piston are directly above one
another.

I n case of doubt, continue to run engine and then

check cylinders for leakage again after some time
has elapsed.

Engines 615, 616

E n g i n e 61 7
00-130 Measurement of oil consumption
-- - --

Special tools

Oil dipstick with millimeter scale

for type 11 5.1

Oil dipstick with millimeter scale

for type 123.1

Valve to stop oil return from air-

cooled oil cooler

Temperature gauge

Note

The oil consumption can be measured using the oil

dipstick with the millimeter scale as well as the
accompanying diagram on the back of the recording
chart.

Since there are two different oil dipsticks and differ-

ent recording charts, please note the following points:

Oil dipstick as per part No. 110 589 11 21 00 (blue

handle) is only to be used for engine having an oil
dipstick tube without an oil removal connection, and
oil dipstick as per part No. 11 5 589 15 21 00 (red
handle) only for engines having an oil dipstick tube
designed for oil removal.

Oil dipstick tube without oil removal connection

Recording charts for engines without oil removal

connection (oil dipstick with blue handle)

GermanIEnglish, publication No. 800 99 223 41 a

or 8009922300b

FrenchISpanish, publication No. 800 99 223 42 a

or 800 99 223 01 b

Oil dipstick tube with oil removal connection

00.4-13011
Recording charts for engines with oil removal connec-
tion (oil dipstick with red handle)

GermanIEnglish, publication No. 800 99 402 00

French/Spanish, publication No. 800 99 402 01

The recording charts that go with each particular type

of oil dipstick can be identified by the engine designa-
tions a t the top of the recording chart.

For engine models 616, 617 in type 115.1 and model

61 7 in type 123.1, it is necessary to f i t the check
valve between the air-cooled oil cooler and upper oil
hose so that the oil will not run back out of the oil
cooler during the measurement.

Should the check valve not fit for lack of space, it is

to be inserted with the aid of a pipe bend and con-
necting pipe.

View showing engine 61 7

Prior to measuring consumption, remember to vent

air-cooled oil cooler.

To do so, clip two transparent plastic hoses onto the

vent plugs attached to the check valve. Remove
filler cap from valve cover and push both hoses into
the filler hole.

Caution:
To avoid oil ejection you are recommended to use
a filler cap having two holes (outside diameter of
hoses).

The procedure needed for the consumption measure-

ment i s described on the front of the recording chart.

In order to avoid incorrect readings, check engine

oil for fuel dilution prior to commencing.
07.1-100 Adjustment of idle speed and idle speed adjuster

A. Engine 61 5, 616 M-injection pump with pneumatic governor

Standard version
@ a@ @ @ @ up to 1975

Testing and adjusting data

Idle speed 700-800lm in

National version @1976

Identification: Information plate in national language on cross member in front of radiator.

Adjust engines according to data of respective emission control information plate.
Color code: black

ldle speed l l m i n

Special tools

Oil telethermometer

Adaptor for revolution counter

Conventional tool

Revolution counter, mechanical with hexagonal adaptor e.g. made by Gann, D-7000 Stuttgart 1
- -
Note

Do not adjust idle speed when engine is too hot, e.g.

immediately following a fast ride or after measuring
output on output dynamometer.

Adjustment

1 Switch off air conditioner or automatic climate

control. Move selector lever in position "P".

2 Connect revolution counter. Use adaptor when

connecting mechanical revolution counter.

3 Run engine t o 75-85 "C oil temperature.

4 Check regulating linkage for easy operation and

wear.

5 Turn idle speed adjuster completely to the right.

6 Check distance between adjusting ring and guide
lever and adjust, if required. Nominal dimension
approx. 0.1 mm.

7 Disconnect connecting rod (3). Check throttle

valve and check valve flap for easy operation.

8 Check idle speed and adjust to specified speed by

means of idle speed adjusting screw ( 4 ) , if required.
I f the idle speed cannot be adjusted, check vacuum
line, sealing rings for tickler shaft, governor housing,
governor diaphragm for leaks (07.1-125).

3 Connecting rod
4 Idle speed adjusting screw

9 Attach connecting rod (3) free of tension. Adjust

regulating linkage, i f required (30-300).

10 Set selector lever to driving position (automatic

transmission), engage air conditioner, turn power
steering to full lock, engine should run smoothly.
Readjust speed, if required.

1 1 Set idle speed adjuster by turning knob counter-

clockwise, approx. 112 turn idle travel should be
available until idle speed increases. Adjust idle travel
with adjusting screw (arrow) if required.
B. Engine 61 5, 616, 617 MW and MIRSF-injection pump with mechanical governor

Standard version
@ aa @up to 1978.@up to 1975. @I

Testing and adjusting data

njectlon pump
Engine Idle speed 1 /min

aa starting 1979. @ @ starting 1976

Identification: Information plate in national language on cross member in front of radiator.

Adjust engines according to data of respective emission control information plate.

c9
Identification: lnjection pump governor housing lead-sealed.

@@
Color code: @ black
Special tools

Oil telethermometer

Adaptor for revolution counter

Conventional tool

Revolution counter, mechanical with hexagonal adaptor e.g. made by Gann, D-7000 Stuttgart 1
- -

Note

Do not adjust engine when i t i s too hot, e.g. imme-

diately following a fast ride or after measuring output
on output dynamometer.

Adjustment

1 Switch off air conditioner or automatic climate

control. Move selector lever into position "P".
2 Connect revolution counter.
Use adaptor when connecting mechanical revolution
counter.

3 Run engine to 75-85 "C oil temperature.

4 Check regulating linkage for easy operation and

wear.

5 Turn idle speed adjuster completely to the right

and check distance between adjusting ring and shaped
spring or nipple and clip on shaped spring and adjust,
if required. Nominal dimension = approx. 1.0 mm.

Attention!
Check whether shaped spring (arrow) has been correct-
ly installed.
 1 Cable control for increasing speed
2 Shaped spring
3 Adjusting ringlnipple
4 Guide lever

6 Check whether Bowden wire for Tempomat/cruise

control rests free of tension against regulating lever
(arrow). For this purpose, push shutoff lever up to
stop. Adjust Bowden wire with adjusting nut ( I ) , if
required.

Release shutoff lever (idle speed position). In this

position, Bowden wire is slack.

Engine 61 7 in model 115.1

Engine 616, 617 in model 123.1

7 Disconnect connecting rod (2) on guide lever (1).

8 Check idle speed, loosen counternut (3) if re-

quired and set idle speed to specified speed by means
of idle speed adjusting screw (4).

Engine 6 1 7 . 9 1 0 with MW-injection pump

1 Guide lever
2 Connecting rod
3 Counternut
4 Idle speed adjusting screw

Engine 616, 6 1 7 with MW-injection pump

Use box wrench to avoid damage to adjusting screw

(4).

Engine 61 5, 616, 61 7 with MIRSF-injection pump

9 Attach connecting rod free of tension. Adjust

regulating linkage, if required (30-300).

10 Place selector lever into driving position (auto-

matic transmission), switch on air conditioner, turn
power steering to full lock, engine should run smooth-
ly. Readjust speed, i f required.

11 Accelerate with accelerator pedal, while simul-

taneously turning idle speed adjuster counterclock-
wise. Speed should now amount to 1000-1 100/min.
Adjust with adjusting screw (arrow in fig. item 12), if
required.
Run engine for some time at this speed. I f speed
increases automatically, slightly reduce speed at
adjusting screw.

Attention!
When the speed is set higher, the idle speed control
range is left. As a result, the engine speed can increase
up to max speed (unloaded).

12 Adjust idle speed adjuster by turning knob

counterclockwise, approx. 112 turn idle travel should
be available until idle speed increases. Set idle speed
by means of adjusting screw (arrow), if required.
 Test values

Special tools

Oil telethermometer

Adaptor for revolution counter 110

6 16 589 00 63 00

Conventional tool
- - -

Revolution counter, mechanical with hexagonal adaptor e.g. made by Gann, D-7000 Stuttgart 1

festing

1 Connect revolution counter.

Use adaptor when connecting mechanical revolution
counter.
2 Run engine to 75-85 "C oil temperature.

3 Slowly accelerate with accelerator pedal and read

revolution counter. Specified engine speed should be
attained.

Adjustment (M-injection pump with pneumatic

governor)

4 Adjust speed by means of full load stop screw (1)

on throttle unit.

Screwing in = speed decrease

Screwing out = speed increase

1 Full load stop screw

2 Regulating lever
a = Adjustment max 2 mm

Adjustment ("a") of throttle valve should not exceed

max 2 mm.

If the full load stop screw i s screwed in s t i l l further,

the air feed will be throttled and driving performance
will drop.

I f the throttle unit can no longer be adjusted, tension

or slacken governor spring by means of compensating
washers (07.1-1 30).

5 I f the respective speed is not attained on MW and

MJRSF-injectionpumps, check for presence of vacuum
at vacuum box on injection pump. For this purpose,
pull off hose on vacuum box. I f the speed is s t i l l not
attained, remove injection pump and adjust maximum
speed free of load on a Bosch injection pump test
bench.
07.1-125 Checking pneumatic governor of injection pump for leaks (engine 61 5.61 6 )

Test values mbar (mm Hg)

-

Vacuum 70-90 (50-70)

Conventional tools

Vacuum meter, connecting nipple

- -

Checking

1 Unscrew vacuum line on governor of injection

Pump-

2 Screw in connecting nipple (2).

3 Push adjusting lever on injection pump completely

forward to stop and plug on test hose ( 1).

1 Test hose
2 Connecting nipple

4 Release adjusting lever and read test value.

5 Watch vacuum meter for constant pressure.

6 If pressure drops, the double thread connection

for the vacuum line, the O-rings for the tickler shaft,
the regulator housing or the regulator diaphragm may
be leaking. Remove leaks, if any, or replace diaphragm
of injection pump (07.1-215).
 .......................... ......................................

07.1-130 Adjusting governor spring of injection pump (engine 615,616)

Adjusting

Unscrew governor cover and remove governor spring

(13). Make sure that the governor spring (13) and the
compensating washers (14) are not falling out when
removing governor cover.

Putting in = speed increases

Taking out = speed decreases

A compensating washer 1 mm thick increases the

engine speed by approx. 120-1 501min. Compensat-
ing washers are available as follows:

0.5 mm thick
1.0 mm thick
2.0 mm thick

1 0 Diaphragm
13 Governor spring
14 Compensating washer
07.1-135 Checking injection nozzles

Test values

lnjection nozzles of used injection

61 5.941
616 (48 k W )

616 (53 kW)

00starting 1979
Identification only: Injection pump with lead-sealed governor housing.

DN OSD 220

@ @ starting 1979
Identification: l njection pump with green type-rating plate.

) The difference in opening pressure of injection nozzles within one engine should not amount to more than 5 bar gauge
pressure.
2 , Starting 1979 nozzle holder with edge-type filter.
) Engine 616, 61 7 starting from increased output.

Tightening torques Nm

Injection nozzle upper and lower half 70-80

- - - --
Special tools

Torque wrench 112" square,

40-130 Nm

Socket 27 mm, 112" square

for injection nozzle

Cleaning kit

Conventional tools

e.g. made by Bosch, 0-7000 Stuttgart

Tester EFEP 60 H
Order no. 0 681 200 502

e.g. made by Bosch, D-7000 Stuttgart

Cleaning needle 0.13 mm
Order no. KDEP 290013

Note

Use only clean testing oil or filtered diesel fuel for

testing. When testing a nozzle, never move hand into
jet of a nozzle. Jet will deeply enter flesh and will
destroy the tissue. Fuel entering into blood may cause
blood poisoning.

Attention!
The shutoff valve of pressure gauge should remain
closed during jet and buzzing test, since otherwise
the pressure gauge may be damaged by excessive
pressure increase.
The injection nozzle with Bosch designation DN 0
SD 240 is a perforated pintle nozzle. This nozzle
differs from the pintle nozzle by a crosswise and
lengthwise bore (14 and 15) in throttle pintle. In
addition, a maintenance-free rod-type filter (13) is
pressed into top of injection nozzle holder (7).

Nozzle needle
Nozzle body
Nozzle holder element
Pressure pin
lnjection nozzle holder bottom
Compression spring
Injection nozzle holder top
Leak oil connection
Fuel feed
Steel washer
Ring groove and feed bores
Pressure chamber in nozzle body
Rod-type filter
Crosswise bore
Lengthwise bore

Testing

1 Remove injection nozzles (07.1-230).

2 Connect removed injection nozzle to tester. With

pressure gauge switched off, plunge down energeti-
cally several times. With a perfectly moving nozzle
needle nozzle should buzz together with a high
whistling sound.

3 Jet test with shutoff valve closed. Insert injection

nozzle into tester. At short, fast partial strokes
(approx. 2 strokes per second) the jet should be
rather concentrated and should break well. lndividual
drops, diagonal or diagonally broken jets, slightly
wide jets are of no significance for combustion in
engine.

A Good injection nozzle

Jet concentrated and well atomized
B Damaged injection nozzle
Jet too wide, streaky and not concentrated
4 Test longitudinal bore (15) in throttle pintle. At
slow, uniform downward movement of hand lever
(approx. 4-6 seconds per stroke) a distinct, vertical
cord-li ke jet (arrow) should come out of longitudinal
bore (15). If no cord-like jet comes out, check longi-
tudinal bore with cleaning needle 0.13 mm dia for
unobstructed passage. I f the longitudinal bore is clear,
the injection nozzle can be used again.

Note: Test procedure also applies to new injection

nozzles.

14 Crosswise bore
15 Lengthwise bore

5 Buzzing test. Push hand lever slowly fully down

(approx. 1 stroke per second); a damped buzzing of
injection nozzle should be heard.

I f the jet or the buzzing test are not in order, flush

injection nozzle by means of several short, fast full
strokes ( 2 strokes per second). The jet should be
concentrated and emerge with a clearly heard, high
whistling sound. Replace injection nozzle if required.

6 Test opening pressure of injection nozzle.

Slowly push hand lever down (1 stroke per second)

with shutoff valve open. When ejection begins, read
ejection pressure; injection nozzle should buzz dis-
tinctively. Set injection nozzle to specified ejection
pressure (opening pressure), if required (07.1-137).

7 Check injection nozzle for leaks.

With shutoff valve open, slowly push pump lever down

up to ejection pressure. Release pump lever, ejection
pressure should remain constant. I n the event of leaks,
disassemble injection nozzle, clean, assemble and ad-
just (07.1-137).
07.1-137 Disassembly, cleaning, assembly and adjustment of injection nozzles

Test values

Injection nozzles with used injection

Standard version and @ 7

(J

a@ starting 1979
Identification @ only injection pump with lead-sealed governor housing.

@ @ starting 1979
ldentif ication l njection pump with green typerating plate.

' ) The difference in opening pressure of injection nozzles within one engine should not amount to more than 5 bar gauge
pressure.
2, Starting 1979 nozzle holder with edge-type filter.
3 , Engine 616, 61 7 starting from increased output.

Tightening torques Nm

Injection nozzle upper and lower half 70-80

Special tools

Torque wrench 112" square,

000 589 22 21 00
40-130 Nm

Socket 27 mm, 112" square

for injection nozzle

Cleaning kit

Conventional tools

e.g. made by Bosch, D-7000 Stuttgart

Tester EFEP 60 H
Order no. 0 681 200 502

e.g. made by Bosch, 0-7000 Stuttgart

Cleaning needle 0.1 3 mm dia
Order nor. KDEP 290013

Note

The injection nozzle with Bosch designation DN 0

SD 240 i s a perforated pintle nozzle. It differs from
pintle nozzle by a crosswise bore and a longitudinal
bore (14 and 15) in throttle pintle. I n addition, a
maintenance-free rod-type filter (13) i s pressed into
injection nozzle holder top (7).

The advantage of a perforated pintle nozzle is better

injection at lower volume and less load, as well as a
reduction of coking on ring gap.

Nozzle needle
Nozzle body
Nozzle holder element
Pressure pin
lnjection nozzle holder bottom
Compression spring
lnjection nozzle holder top
Leak oil connection
Fuel feed
Steel washer
Ring groove and feed bores
Pressure chamber in nozzle body
Rod-type filter
Crosswise bore
Lengthwise bore
Disassembly

1 Clamp injection nozzle holder top (7) with

protective jaws into vise in such a manner that the
leak oil line connections are not damaged.

2 Loosen injection nozzle holder bottom (5) with

socket wrench insert and screw off.

5 lnjection nozzle holder bottom

7 Injection nozzle holder top

3 Remove steel washer ( l o ) ,compression spring

(6),pressure pin (4),nozzle holder element (3) and
nozzle body (2) with nozzle needle (1).

Attention!
During disassembly make sure that the nozzle body,
the nozzle needle and the individual components are
not mixed up among each other.

Cleaning

4 Brush off combustion deposits outside on face of

nozzle body ( 2 ) ,mainly around nozzle mouth, by
means of a brass brush.

Touch up nozzle holder element (3) and nozzle body

(2) on face of both sides on a surface plate.

5 Clean pressure chamber (5) of nozzle body by

means of ring groove scraper.

1 Ring groove 7 Nozzle mouth

2 Nozzle body 8 Spray pintle
3 Feed bore 9 Throttle pin
4 Nozzle needle 10 Needle seat
5 Pressure chamber 11 Pressure shoulder
6 Mouth of feed bores in 12 Needle stem
pressure chamber 13 Pressure pin
6 Clean nozzle needle seat in nozzle body with
cleaning cutter from inside out. Do not clean from
outside (to guide cleaning cutter or to prevent
canting). Do not exert excessive pressure with
cleaning cutter.

7 Clean longitudinal and cross bore of nozzle needle

with cleaning needle 0.13 mm dia.

8 Clean nozzle needle with brass brush.

Testing nozzle needle

9 Visual test. Upon cleaning, test used nozzles visual-

ly. Test nozzle needle for dented or rough needle seat
and for worn or damaged spray pintle. Replace da-
maged nozzles.

10 Slide test. For this purpose, immerse nozzle

needle and nozzle body in filtered diesel fuel and
insert nozzle needle into nozzle body. With nozzle
needle held vertically the nozzle needle, which is
pulled out by approx. one third, should slide back
on i t s seat under its own weight. Replace injection
nozzle, if required.

Assembly

11 Insert all parts in vice versa sequence into injec-

tion nozzle holder bottom (5) and screw on injection
nozzle holder top (71, while inserting pressure pin (4)
with bore into nozzle needle (1 ).

1 Nozzle needle 5 Injection nozzle holder bottom

2 Nozzle body 6 Compression spring
3 Nozzle holder element 7 Injection nozzle holder top
4 Pressure pin 10 Steel washer

12 Clamp injection nozzle holder top (7) with

protective jaws into vise and tighten injection nozzle
holder bottom (5) to 70-80 Nm.
Testing

13 Test injection nozzles for jet, buzzing noise, open-

ing (ejection) pressure and for leaks (07.1-135).

Adjusting

14 Install or remove steel washers (10) between

compression spring (6) and injection nozzle holder
top (7) to maintain specified ejection (opening) pres-
sure, if required for adjustment.

Putting in = increased ejection pressure

Taking out = decreased ejection pressure

Washers are available 1.0 to 1.8 mm thick in steps of

0.05 mm. An increase of preload by 0.05 mm in-
creases ejection pressure by approx. 3.0 bar gauge
pressure.
07.1-140 Venting of injection system

Venting fuel filter

Model 115.1

1 Loosen venting screw (2) or with fuel filter with-

out venting screw loosen hollow screw (2and 4).

Model 123.1

Loosen hollow screw (3) and keep pumping with hand

pump until fuel pumps out free of bubbles. Tighten
hollow screw again.
2 Loosen actuating button (3) of manual delivery
pump (on engine 617 in model 115.1 not required)
and keep actuating manual delivery pump until fuel
emerges free of bubbles at vent screw (2) or hollow
screw (2 and 4). Tighten vent screw or hollow screw
again.

Manual delivery pump

Engine 617 in model 115.1

Venting injection pump

3 M-injection pump with pneumatic governor. Loosen

vent screw (arrow) on injection pump and also keep
pumping with hand pump until fuel emerges free of
bubbles. Tighten vent screw again.
4 M W and MIRSF-injection pump with mechanical
governor. Keep pumping with hand pump until over-
flow valve on injection pump opens (audible buzzing
noise).

5 Tighten actuating button of manual delivery pump

again.

Note: This will force pump piston on a sealing ring

and the hand pump is sealed in outward direction.
With actuating button released, the manual delivery
pump will leak during operation and air may enter
fuel system.

6 Run engine and check whether all connections are

leaktight.
07.1-145 Checking fuel pump and overflow valve

Test values
Fuel pump

Engine

Vacuum

Measuring point

Delivery pressure

bar gauge pressure

Delivery end pressure

bar gauge pressure

Fuel overflow valve

Special tools

Clamp for fuel hose 000 589 40 37 00

Tester for fuel pump

Measuring vacuum

1 Connect tester at fuel input (1) on fuel pump. For

this purpose, remove fuel feed line. Vent injection
system (07.1-140).

Measure vacuum a t idle speed. For this purpose, pinch

hose (arrow) on tester behind pressure gauge with a
clamp.

If the value is not attained, replace suction and pres-

sure valves or replace fuel pump (07.1-235).

Checking fuel delivery pressure

2 Unscrew fuel line (3) between fuel pump and fuel

main filter.

3 Connect tester. For this purpose, connect fuel line

together with hose line for tester to a double hollow
screw and closing nut. Connect other hose line of
tester to fuel filter.

4 Vent injection system (07.1-140).

5 Run engine to operating temperature.

6 Measure fuel delivery pressure at idle speed and at

3000lmin.

At idle speed 0.6-0.8 bar gauge pressure.

At 3000/rnin at least 0.8 bar gauge pressure.

7 If delivery pressure is too low:

a) Check overflow valve, while removing, disassembl-

ing and cleaning overflow valve on injection pump.

Increase preload of compression spring (2). For this

purpose, lengthen compression spring to 26-27 mm.

1 Ball 4 Sealing ring

2 Compression spring 5 Closing plug
3 Housing

b) Check fuel filter for contamination. Mount new

filter element with housing (3) and gasket (4), if
required.

c) Replace suction and pressure valve or replace fuel

pump (07.1-235).

Checking fuel delivery end pressure

8 Pinch fuel return hose with a clamp (arrow)

9 Measure fuel delivery end pressure at idle speed

and at 3000lmin.

At idle speed min. 1.1 bar gauge pressure.

At 3000tmin a t least 1.3 bar gauge pressure.

10 I f the delivery end pressure is too low, replace

suction and pressure valves or replace fuel pump
(07.1 -235).
 ....................................... ,,....,,, .

07.1-150 Checking key starter for leaks

A. Without tester

Note for vehicles with diaphragm vacuum pump

If engine oil shows up in vacuum lines or in brake

unit, the diaphragm of the vacuum box or the dia-
phragm in vacuum pump may be defective.

If engine oil shows up, replace vacuum box as well

as the vacuum lines containing oil, if required. Repair
vacuum pump and replace brake unit, if these units
are showing oil on connection for vacuum line.

If a leaking diaphragm in vacuum pump or a leaking

vacuum box on injection pump are responsible for
oil entering combustion chambers via intake pipe,
the resulting increased combustion temperature may
lead to prechamber damage.

If the vacuum lines are showing an intensive black

color along their entire length, the reason may be
engine oil in combustion chamber. In such a case it
will be of advantage to check all prechambers.

Re~lace re chambers with cracks in bottom (arrows)

or burnt (scale-covered) ball pin surface (arrow), if
not, damage to engine caused by chips or peelings
from prechamber components may be expected.

Note: The piston-type vacuum pump i s installed on

standard version since June 1980 and on national
version since model year 1981.
Checkup

1 Run engine.

2 Pull vacuum line (brown) from T-fitting (7) and

check for presence of vacuum.

a) I f there is no vacuum, unscrew vacuum line with

T-fitting on vacuum pump and on brake unit.

Check throttle in T-fitting for unobstructed passage

and blow out with compressed air, if required.

Note: On vehicles with diaphragm vacuum pump. If

throttle i s oiled up, the diaphragm in vacuum pump
may be defective. This may be the case, if engine oil
i s seen on connection of vacuum line (pump end).
Reconditioning of vacuum pump i s described in repair
instructions "Brakes model 115 and 123".

b) I f vacuum is available at T-f itting, connect vacuum

box (3) and T-f itting (7) to each other by means of a
hose.

The vacuum coming from vacuum pump (8) is now

acting directly against diaphragm in vacuum box (3)
and will pull the control rod in injection pump into
stop position. If the engine is not stopping immedia-
tely, replace vacuum box (07.1-220).

If the engine stops immediately, the vacuum box is

in order. The complaint may then have been caused
by a sticking valve (1) in steering lock. For replacing
valve, refer to repair instructions "Steering model
115and 123".

Attention!
Do not mix up vacuum lines during assembly.
3 Run engine, check vacuum control unit and valve
in steering lock for function and leaks.

Valve 9 Switchover valve br = brown

Cam 10 Vacuum control valve brlbl = brownlblue
Vacuum control unit injection pump swlrt = blacklred
Brake unit a Suction line swlgn = blacklgreen
Check valve b Vent line sw =black
T-piece with installed choke (orifice) c Central lock swlws = blacklwhite
Vacuum pump d Control line
Vacuum control unit for transmission
B. W i t h tester

Data

Permissible leakiness of system 6 mbarlmin at 400 mbar vacuum

Permissible leakiness of individual components 5 mbarlmin a t 300 mbar vacuum

Plug-on length of connections 12k2mm

-

Color code of vacuum lines for diesel key starting

- -

Vacuum line Color code

Suction line from distributor to

brown
valve for key starting (100)

Control line from valve for key starting to

shutoff box of injection pump (101)

Special tool

Tester for vacuum

Checkup
- --

1 Set ignition key on steering lock t o position "2".

2 Pull suction line (100) out of connection (17).

Layout without central interlock and air

conditioner/automatic climate control
3 Connect tester (83) and evacuate.

Layout with central interlock or air conditioner

4 If the pressure gauge shows a vacuum decrease the

valve for key starting on steering lock is leaking.

5 Replace valve for key starting system on steering

lock (46-640).

Attention!
Prior to replacing valve for key starting and vacuum
box of injection pump, check hose lines and their
connections.

6 If readout on pressure gauge i s not changing, the

valve for key starting system i s not leaking.

7 Turn ignition key on steering lock back to position

"1 or "0".
"

8 Evacuate system with tester (83).

9 If pressure gauge shows a vacuum decrease, the

vacuum box or the valve may be leaking.

10 In such a case, disconnect tester (83) on suction

line (100).

11 Pull control line (101) with connection (17) from

vacuum box of injection pump.
12 Connect tester (83) to vacuum box (arrow) and
evacuate.

13 If pressure gauge shows a vacuum decrease, the

vacuum box of injection pump is leaking.

14 Replace vacuum box of injection pump (07.1-

220).

15 If readout on pressure gauge is not changing, the

vacuum box of the injection pump is leaktight and
the leak is at valve for key starting system. Replace
valve vor key starting system (46-640).

Valve 9 Switchover valve br = brown

Cam 10 Vacuum control valve brlbl = brownlblue
Vacuum control unit injection pump swlrt = blacklred
Brake unit a Suction line sw = black
Check valve b Vent line swlws = blacklwhite
T-fitting with installed choke (orifice) c Central lock
Vacuum pump d Control line
Vacuum control unit for transmission
07.1-200 Removal and installation of injection pump

A. Engine 615,616 M-injection pump with pneumatic governor

Standard version

Injection pump with governor and delivery pump for operating at altitudes up to 2000 rn above sea level

Bosch designation
(abbreviation)

4 M 55 C 320 RS 47

PIMN 60 M 25 DR

EPIMN 60 M 44 DR

Engine 615 for operating at altitudes above 2000 m above sea level

11 5.1
615.912
:;7 55
320 RS 47 EPIMN 60 M 23 DR
. FPIK 22
M 13
615.913
:;7 50 320 RS l4
EPIMN 60 M 25 DR

') Data concerning control rod path represent the path of the control rod from full load stop to outermost stop position. By
means of these data for the control rod and compensating path, the injection pump can be regulated occasionally and in an
emergency without a test bench.
* ) Accurate regulation and adjustment of injection pump is possible on an injection pump test bench only. For workshops which
own such a test bench, the required data sheets for the various pumps are available.
3 , In the event of replacements,@version vehicles are supplied with injection pumps model year 1975176 only.
4, Replaced by M 38 DR when stocks were used up.
5 ) On engines with injection nozzles DN 0 SD 1510, as a result of the shorter compensating path, the control rod path amounts to
14.5-14.7 mm and on injection pumps for altitudes above 2000 m i t is 13.6-13.8 mm.

a
Identification: Full load stop screw and governor housing lead-sealed.
Model year 1975/76

1 615.913 1 ri: 50 320 l4 1 EPIMN 60 M 28 DR I FPIK 22

13 14.2-14.3
1st edition

1 14.5-14.6
/ 2.4 a
3rd edition
Model year 1977178

Model engine Injection pump Governor Delivery pump Control rod Test values2 )
Bosch designation Bosch designation Bosch path including MB-sheet
(abbreviation) designation compensating Date or
path1 ) mm edition

615.941
rGr 55 320 60 EPlMN 60 M 48 DR
FPIK 22
123.1
M 14
PES 55 320 R S 60 EP/MN 60 M 47 DR
616.912
(M1

Model year 1979

61 5.941 3 ) ' PES 4 M 55 C 320 RS 60 EP/MN 60 M 48 DR FPIK 22 M 14 13,8-13.9 2.2 g

123.1 (MI 1st edition

) Data concerning control rod path represent the path of the control rod from full load stop to outermost stop position. By
means of these data for the control rod and compensating path, the injection pump can be regulated occasionally and in an
emergency without a test bench.
) Accurate regulation and adjustment of injection pump is possible on an injection pump test bench only. For workshops which
own such a test bench, the required data sheets for the various pumps are available.
3 , Up to February 1979.

@
Identification: green information plate.

Model year 1975176

' 1 means
Data concerning control rod path represent the path of the control rod from full load stop to outermost stop position. By
of these data for the control rod and compensating path, the injection pump can be regulated occasionally and in an
emergency without a test bench.
) Accurate regulation and adjustment of injection pump is possible on an injection pump test bench only. For workshops which
own such a test bench, the required data sheets for the various pumps are available.

Test values

Engine 615.9121941 6 15.9131940 616

Begin of delivery before TDC

in compression stroke ) 2 , '
'1 The injection pump i s in begin of delivery position, when the marking line on camshaft of injection pump i s in alignment with
line on flange of injection pump.
1 The begin of delivery position is checked and set following installation of injection pump according t o overflow method
(07.1-1101115).

Tightening torques Engine Nm

Pipe connection for pressure valves 615,616 35

Injection lines 615,616 25

-
Special tools

Torque wrench 112" square,

15-65 Nm

Socket wrench insert 13 mm,

318" square

Box wrench insert open, 17 mm,

112" square for injection lines

Overflow pipe 636 58902 2300

Note

If lower fastening nut of injection pump (oil filter

flange without recess) i s poorly accessible, unscrew
upper fastening screw from oil filter flange first. For
this purpose, remove lefthand front wheel and un-
screw fastening screw by means of an extended socket
wrench. In addition, on engines 615.912 and 616,
unscrew oil hoses from air-oil cooler on oil filter top.

Starting with the following chassis end numbers, an

oil filter flange with recess is installed for better
access to bottom fastening nut of injection pump on
models 115.

Series production

Model Starting chassis end no.

Removal

1 Unscrew injection lines, vacuum line and fuel lines

on injection pump. Plug closing caps on connections
for injection lines and fuel hoses on injection pump.

2 Disconnect connecting rod on tickler.

3 Disconnect start-stop cable control on adjusting

lever (1) of injection pump. For this purpose, remove
cotter pin, washer (5),screw (3) on angle bracket and
remove wire coil (4) with clamp.

1 Adjusting lever
2 Oblong eye
3 Screw - angle bracket
4 Wire coil
5 Washer

4 Unscrew hex nut on supporting bell and fastening

nuts of injection pump, then pull injection pump out
of cylinder crankcase. Remove coupling sleeve from
driver of injection pump or from drive shaft.

Note: When replacing a driver, apply counterhold for

loosening hex nut by means of notched tooth wrench,
then pull driver from injection pump shaft by means
of puller. Clean shaft stub and driver; the two cones
should be absolutely clean and free of grease.

When mounting a new driver, pay attention to Wood-

ruff key and markings (arrows).
Installation

Prior to installing injection pump, check control rod

for easy operation. I f required, make operable as
follows:

a) Remove closing cap (arrow) of control rod.

b) Push adjusting lever from stop to start position.

Control rod should return automatically.

c) If control rod is hard to move, which i s caused by

resinification, fill clean gasoline into fuel feed
connection and permit to act for a short period on
elements.

d) Move control rod back and forth until it is freely

operating.

5 Set crankshaft to the following values in compres-

sion stroke of firqt cylinder.

61 5.9131940 26' before TDC

615.91 21941 24' before TDC
616 24" before TDC

6 Slip coupling sleeve on intermediate gear shaft.

7 Set injection pump to begin of delivery. For this

purpose, rotate pump shaft until tooth gap on driver
and marking on injection pump are in alignment
(arrows).
8 Mount new gasket.

9 Introduce injection pump in such a manner that

the studs are in center of oblong holes (slots). This
will permit swivelling in both directions for precision
adjustment.

Note: Following precision adjustment, a distance of

approx. 80 mm should be available from cylinder
crankcase to center of pipe connection for injection
lines to remove glow plugs.

10 Mount washers and slightly tighten injection

pump by means of hex nuts.

11 Check begin of delivery and adjust (07.1-110

and 1 1 5).

12 Tighten fastening nuts on front flange and on

supporting bell.

13 Check oil level of injection pump and correct, if

required. For this purpose, unscrew check plug (1).
If oil level is too high, loosen governor cover and raise
slightly so that the fuel-oil mixture can flow out. When
the oil level is too low, unscrew filter (2) and add
engine oil up to check bore.

1 Check plug
2 Filter
14 Check position of overflow pipe and correct
according to illustration, if required. For this purpose,
loosen hollow screw and correct overflow pipe accord-
ing to illustration.

1 st version

2nd version

3rd version

15 Mount start-stop cable control and adjust

(07.1-340).

16 Run engine and check all connections for leaks.

17 Check idle speed and adjust, if required (07.1-

100).
Mixture preparation
Engine 61 5, 616 M-injection pump with pneumatic governor

25 Gasket
1 Leak hose 26 Nut Sealing r i n g
2 Closing p l u g 27 Snap ring Delivery valve
3 l n j e c t i o n nozzle holder t o p 28 Drive p i n i o n Holder
3a Steel washer 29 Woodruff key Suction valve
4 Compression spring 30 lnjection p u m p Screw connection
5 Pressure p i n 39 Nut Sealing r i n g
6 Nozzle holder insert 40 Washer H o l l o w screw
7 Nozzle b o d y 41 Woodruff key Washer
7a Nozzle needle 42 Intermediate gear shaft Snap r i n g
8 l n j e c t i o n nozzle holder b o t t o m 43 Thrust r i n g Nut
9 Small nozzle plate 1 st version 44 Bushing Screw
9a Small nozzle plate 2 n d version 45 Segment f o r injection t i m e r Snap r i n g
9b Small nozzle plate 3 r d version 46 Governor weight Fastening bracket
10 l n j e c t i o n line 47 Bolt Nut
11 l n j e c t i o n line 48 Compression spring Fastening bell
12 l n j e c t i o n line 49 Bolt Governor spring
13 l n j e c t i o n line 50 Segment flange Diaphragm
15 Screw 52 Collar screw Gasket
16 Pipe holder 53 Washer Poppet housing
17 Nut 54 Nut Hose c l a m p Sweden version
18 Pipe connection 55 Gasket Clamping jaw l o c k
19 Compression spring 56 Fuel manual delivery p u m p Snap r i n g
20 Delivery valve 57 Rubber sealing r i n g Screw
21 Pressure valve carrier 58 Connection O v e r f l o w pipe
22 Copper sealing r i n g 58a Sealing r i n g Hose
23 Sleeve 59 Fuel delivery p u m p O-ring
24 Circlip 60 Screw connection
Fuel filter
Engine 615, 616 in model 115.1

1 Leak hose of injection nozzle 13 Overflow valve 2 0 Rubber sealing ring

2 H o l l o w screw 14 Fuel line 21 Spring plate
3 Sealing ring 15 F u e l l i n e 2 2 Compression spring
4 Ring fitting 1 6 Fuel filter t o p 2 3 Fuel filter b o t t o m
10 Hose clamp 1 7 Fuel filter element 2 8 Hollow screw w i t h calibrated bore
11 Fuel expanding hose 1 8 Screw 3 0 Injection p u m p
12 Return line 1 9 Sealing ring
Engine 615, 616 in model 123.1

1 Leak hose of injection nozzle 7 Hollow screw 13 Overflow valve

2 Hollow screw with calibrated bore 8 Sealing ring 14 Fuel line
3 Sealing ring 9 O-ring 15 Fuel line
4 Ring fitting 10 Hose clamp 16 Fuel filter top
5 Hollow screw 1 1 Fuel expanding hose 17 Fuel filter
6 Sealing ring 12 Return line 30 Injection pump
B. Engine 61 5. 616. 617 MW and M/RSF-injection pump with mechanical governor

Standard version and @ a

MW 551320 RS 12 W 35012200 MW 15

) Accurate regulation and adjustment of injection pump is possible on an injection pump test bench only. For workshops which
own such a test bench, the required data sheets for the various pumps are available.
2, Production starting chassis end no. 054194, October 1977.
Production starting chassis end no. 084808, August 1978.
4 , Governor designation is included in injection pump combination number.

00
Identificationainjection pump only with lead-sealed governor housing and full load stop screw (on MW-injec-
tion pump only)

Model year 1975176

115.1
-
617.910 PES 5 MW 551320 RS 3
(MW)
RW 35012200 MW 10
rc322 3,O a
4th edition

Model year 1977/78

RW 35012200 MW 20

Starting model year 1979

Accurate regulation and adjustment of injection pump is possible on an injection pump test bench only. For workshops which
own such a test bench, the required data sheets for the various pumps are available.
2, Governor designation i s included in injection pump combination number.
--
Model

Model year 1980181

Identification

-
'
Engine

61 6.91 2

61 7.91 2
Injection pump
Bosch designation
(abbreviation

only: lnjection pump with lead-sealed governor housing.

6 1 5.940 PES4 M 50 C 320 RS 103

(MIRSF)

PES 4 M 55 C 320 RS 1 0 4 ~ )
(MIRSF)

PES 4 M 55 C 320 RS 1 0 7 ~ )
(MIRSF)

PES 5 M 55 C 320 RS 105

(MIRSF)

PES 5 M 5 5 C 3 2 0 RS 1 0 8 ~ )
(MIRSF)
Governor
Bosch designation

4,

4,

4,
1
--
Delivery pump
Bosch designation

FPIK 22
M 101

FPIK 22
M 101

FPIK 22
M 101

FPIK 22
M 101

FPIK 22
M 101
Test values )
MB-sheet
Date or edition

2,o g 2
2nd edition

2,4 h 1
1

3rd e d ~ t i o n

2,4 h 1
3rd edition

3,O 1
3rd e d ~ t ~ o n

3,O 1
3rd edit~on

) Accurate regulation and adjustment of injection pump i s possible on an injection pump test bench only. For workshops which
own such a test bench, the required data sheets for the various pumps are available.
2, Starting chassis end no. 084808, August 1978.
3 , Starting November 1980.
4, Governor designation i s included in injection pump combination number.

@@
Identification: green information plate.

Model year 1975176

-
( 61 7.91 0 I PES 5 MW 551320 RS 4 RW 35012200 MW 3 I 3.0 c

115.1

1
61 7.91 0 2 )
I
(MW)

PES 5 MW 551320 RS 4
(MW) I
RW 35012200 MW 11
1
I
FPIK 22
MW3
Eod;dition

I 2nd edition

Model year 1977178

Model year 1979

Model year 1980181

616.91 z3) MW 551320 RS 21 W 37512200 MW 27 2,4 i

1st edition
FPIK 22
MW 21
2nd edition

' 1 Accurate regulation and adjustment of injection pump is possible on an injection pump test bench only. For workshops which
own such a test bench, the required data sheets for the various pumps are available.
* ) lnjection pump with mechanical altitude correction, starting chassis end no. 007590.
3 , lnjection pump with automatic altitude correction.
Test values

Engine 615 616,617

Begin of delivery before TDC in compression stroke' ) ) 26' 24'

Attention!
On iniection DumDs with mechanical governor, push regulating lever o f injection pump t o full load while measuring and pull
o f f vacuum hose from vacuum box.
' ) The injection pump is in begin of delivery position when the marking on camshaft of injection pump i s in alignment with that
on flange of injection pump.
2 , Check begin o f delivery position following installation of injection pump according t o overflow method and adjust (07.1-110
and 115).

f ightening torques Nm

Pipe connection for pressure valve 40-50

lnjection line 25

Special tools

Torque wrench 1 /2" square,

15-65 Nm

Socket wrench insert 13 mm,

318" square

Box wrench insert open, 17 mm, 112" square

for injection lines

Overflow pipe 636 58902 2 3 0 0

11001- 6376

Socket notched tooth 17 x 20,

112" square for pipe connection
MRSF-injection pump

' ) Machine socket 61 7 589 00 09 00 (refer to 07.1-210).

Self-made tool

Box wrench 13 mm refer to Fig. item 4

Note

On engine 617 in model 123.1, remove oil filter

(18-1 10).

On engine 617 in model 115.1, remove battery and

battery frame.
Removal

1 Pull vacuum hose on vacuum box and electric

cable, disconnect regulating rod, unscrew injection
lines and fuel lines on injection pump. Place closing
caps on connections for injection lines and fuel hoses
on injection pump.

2 On MW-injection pumps, unscrew lube oil line (5).

Attention!
Prior to removing lube oil line (5),clean connecting
points.

Model 1 15.1

Model 123.1

3 Unscrew hex screws on supporting holder ( 4 ) and

the three fastening nuts of injection pump. Loosen
fastening screw (3) so that adjustments on slot can
be made.
4 On engine 617 in model 115.1, use self-bent
13 mm box wrench according to drawing for loosen-
ing front fastening nuts.

5 Pull injection pump out of cylinder crankcase.

Remove coupling sleeve from driver of injection
pump or from drive shaft.

Note: When replacing a driver, apply counterhold

with notched tooth wrench for loosening hex nut,
then pull driver from injection pump shaft by means
of puller. Clean shaft stub and driver; the two cones
must be absolutely clean and free of grease.

When mounting a new driver, pay attention to Wood-

ruff key and to markings (arrows).

Installation

Prior to installing a replacement injection pump

proceed as follows:

a) For initial filling, add 0.4 liter engine oil after

removing closing plug (arrow).
b) Check control rod for easy operation (except in-
jection pumps with alt itude adjusting box):

MW-injection pump

Unscrew lower righthand fastening screw (arrow) on

shutoff box.

Insert a plug gauge through bore up to stop. Push

plug gauge slightly against control rod. Move regu-
lating lever on injection pump from idle speed to full
load stop. Plug gauge should closely follow control
rod.

If control rod is hard to move under the influence of

resinification, add clean gasoline into fuel feed con-
nection to act on elements for a short period.

Push control rod back and forth until it i s freely

moving.

MJRSF-injectionpump

Remove closing cap of control rod.

Move regulating lever on injection pump from idle

speed to full load stop. Control rod should return
automatically.
I f control rod is hard to move under influence of resi-
nification, fill clean gasoline into fuel feed connection
to act on elements for a short period.

Push control rod back and forth until it is freely

moving.

The injection pump receives the oil required for lubri-

cation via intermediate gear shaft and hollow camshaft
of injection pump.
The oil flows back into cylinder crankcase via ring
gap (2) on sealing flange of camshaft.

For sealing coupling space between intermediate gear

shaft and camshaft an O-ring (3) is inserted in drive
pinion.

1 Oil inlet
2 Oil outlet
3 O-ring

When removing and installing injection pump, make

sure that the O-ring (3) is not damaged. Always
replace damaged O-rings.

On vehicles with automatic transmission and vacuum

control valve:

Unscrew vacuum control valve from removed injection

pump, screw to injection pump about to be installed
and adjust. For this purpose, push regulating lever of
injection pump to full load and turn vacuum control
valve to the right (arrow) up to noticeable stop. I n
this position, tighten fastening screws.
6 Set crankshaft to begin of delivery in compression
stroke.

7 Mount new gasket.

8 Set injection pump to mark. For this purpose,

rotate camshaft of injection pump until marking line
on camshaft i s in alignment with line on flange (arrows).

9 Slip coupling sleeve on driver and introduce injec-

tion pump. Mount washers and slightly tighten injec-
tion pump by means of hex nuts.

Note: On engine 617 in model 115.1, unscrew oil

hose ( 7 ) for easier access of washer and nut (2).

10 Check begin of delivery and adjust (07.1-1 10

and 115). Then tighten injection pump.

11 Take supporting holder (4) from removed injec-

tion pump.

For attaching supporting holder, use only spacing

washers and hex screws intended for engine. Screw
supporting holder to cylinder crankcase first, and
then tighten fastening screw in oblong hole (slot) of
supporting holder.
12 Vacuum hose on vacuum box, mount electric
cable. Connect all fuel lines.

13 On MW-injection pumps, reattach lube oil line to

injection pump.

14 Mount oil filter and oil filter cover with new

gasket (18-110).

15 Mount battery frame and battery and connect.

16 Vent injection system with manual delivery

pump (07.1-1 40).

17 Check regulating linkage and adjust, if required

(30-300).

18 Run engine to operating temperature and check

all connections for leaks.

19 Check idling speed and adjust, if required

(07.1-100).
Mixture preparation
Engine 616, 617 MW-injection pump with mechanical governor

1 Leak hose 22 Copper sealing ring 4 2 Intermediate gear shaft

2 Closing plug 2 3 Sleeve 4 3 Thrust ring
3 Injection nozzle holder t o p 24 Circlip 44 Bushing
3a Steel washer 25 Gasket 4 5 Segment for injection timer
4 Compression spring 26 N u t 4 6 Governor weight
5 Pressure p i n 27 Snap ring 47 Bolt
6 Nozzle holder insert 28 Drive pinion 48 Compression spring
7 Nozzle body 2 9 Woodruff key 4 9 Bolt
7a Nozzle needle 3 0 Injection p u m p 50 Segment flange
8 lnjection nozzle holder lower half 31 Gasket 52 Collar screw
9 Small nozzle plate 1st version 31a Gasket 53 Washer
9a Small nozzle plate 2 n d version 31 b Steel washer !3 N u t
9b Small nozzle plate 3 r d version 3 2 Vaccum control u n i t 5 5 Gasket
10 Injection line engine 6 1 7 i n model 11 5 5 6 Fuel hand delivery p u m p
11 Injection line 32a Vacuum control u n i t 58 Connection
12 Injection line engine 61 6,617 i n model 1 2 3 58a Sealing ring
13 Injection line 32b Flange 5 9 Fuel delivery p u m p
14 Injection line 33 Washer 60 Screw connection
15 Screw 34 Screw 61 Sealing ring
16 Pipe holder 35 Return spring 62 Compression spring
17 Nut 3 6 Holder 6 3 Delivery and suction valve
18 Pipe connection 3 7 Washer 71 Altitude adjusting box USA version
18a Pipe connection USA version 3 8 Screw 93 Hose clamp Sweden version
19 Compression spring 39 Nut 1 0 5 Fuel line
20 Delivery valve 4 0 Washer 106 Screw connection
21 Delivery valve carrier 41 Woodruff key
Engine 61 5, 616, 61 7 M/RSF-injection pump with mechanical governor
6 3

1 Leak hose 25 Gasket 5 2 Collar screw

2 Closing plug 26 Nut 53 Washer
3 Injection nozzle holder t o p 27 Snap ring 54 N u t
4 Compression spring 28 Drive pinion 5 5 Gasket
5 Pressure p i n 29 Woodruff key 56 Fuel hand delivery p u m p
6 Nozzle holder insert 30 Injection p u m p 57 Rubber sealing ring
7 Nozzle b o d y 31a O-ring 5 8 Connection
7a Nozzle needle 32 Vacuum control u n i t 58aSealing ring
8 Injection nozzle holder b o t t o m 34 Screw 5 9 Fuel delivery p u m p
9a Small nozzle plate 35 Return spring 6 0 Screw connection
1 0 Injection line 36 Holder 6 1 Sealing ring
11 Injection line 38 Screw 6 3 Delivery valve
1 2 Injection line 41 Woodruff key 6 5 Holder
13 Injection line 42 Intermediate gear shaft 6 6 Suction valve
15 Screw 43 Thrust ring 8 0 Washer
1 6 Pipe holder 44 Bushing 8 1 Snap ring
17 N u t 45 Segment f o r injection timer 82 Nut
1 8 Pipe connectron 46 Governor weight 9 3 Hose c l i p Sweden version
1 9 Compression spring 47 Bolt 9 9 O-ring
2 0 Delivery valve 48 Compression spring 1 0 0 Holder
21 Delivery valve carrier 49 Bolt 101 Fastening plate
2 2 Copper sealing ring 50 Segment flange 102 Screw
23 Sleeve 103 Locking plate
24 Circlip
Fuel filter
Engine 617 in model 115.1

1 Leak hose o f injection nozzle Fuel line 22 Compression spring

2 H o l l o w screw Fuel line 23 Fuel filter b o t t o m
3 Sealing ring Fuel filter t o p 24 Spacing ring
4 Ring fitting Fuel filter element 25 Fuel manual delivery p u m p
10 Hose clamp Screw 26 Sealing ring
11 Fuel expanding hose Sealing ring 27 H o l l o w screw
12 Return line Rubber sealing ring 28 H o l l o w screw w i t h calibrated bore
13 Overflow valve Spring retainer 30 Injection p u m p
Engine 615, 616, 617 in model 123.1

1 Leak hose of injection nozzle 7 Hollow screw 13 Overflow valve

2 Hollowscrew 8 Sealing ring 14 Fuel line
3 Sealing ring 9 O-ring 15 Fuel line
4 Ring fitting 1 0 Hose clamp 16 Fuel filter top
5 Hollow screw 11 Fuel expanding hose 17 Fuel filter
6 Sealing ring 12 Return line 30 Injection pump
 07.1-205 Displacing injection pump (after adjusting begin of delivery)

Test values

Engine 615.9121941 615.9 131940 616,617

Begin of delivery before TDC

in compression stroke

Tightening torques

lnjection pump
Designation Engine
abbreviation

Pipe connection for

pressure valve

lnjection line M,MW,M/RSF 615,616,617 25

Special tools

Torque wrench 1 /2" square,

15-65 Nm

Socket wrench insert 13 mm.

3/8" square

Overflow pipe
- - -- - --

Box wrench insert open, 17 mm, 112" square

for injection lines

Displacing

1 Remove and install injection pump (07.1-200).

2 Pull out injection pump and introduce in such a

manner that the studs are in center of oblong holes
(slots).

3 Adjust begin of delivery (07.1-115).

07.1-210 Replacing pipe connection, pressure valve or copper sealing ring of injection pump

Tightening torques

Pipe connection for

pressure valve

Special tools

Torque wrench 112" square,

000 589 27 21 00
15-65 Nm

000 589 68 03 00
112" square for injection lines

Socket wrench insert notched tooth

17 x 20, 112" square for pipe connection 617 589 01 09 00')
MIRSF-injectionpump llOM - 0544

'1 Machine socket wrench insert 617 589 00 09 00 (refer to 07.1-210).

Note

@ starting model year 1975

To reduce hydrocarbons in exhaust gases, the injec-
tion pump is provided with a relief throttle. The relief
throttle i s in pipe connection of injection pump, so
that the pipe connection will be higher.

Engine 616 by 8.5 rnm with M-injection pump.

Engine 616, 617 by 7 mrn with MW-injection pump.

The relief throttle (2) is a plate valve opening in direc-

tion of injection nozzle and provided with a throttle
bore of 0.6 mrn dia. The plate valve (3) is riveted in
space above pressure valve spring.

1 Compression spring
2 Relief throttle
3 Plate valve
4 Valve seat
5 Pipe connection
6 Pressure valve carrier
with pressure valve
The relief throttle permits the fuel to pass in direction
of injection nozzle. The pressure wave from injection
nozzle in direction of injection pump, which is caused
upon injection by the afterpumping effect of the
nozzle needle while closing, is damped by the relief
throttle. This will prevent the pressurewave from
subsequently flowing back to injection nozzle and
from setting up a re-injecting effect there. Re-injec-
tion would result in an increase of hydrocarbons in
emissions.

Modified pipe connection on MIRSF-injection pump

(engine 615,616 and 617)

Since May 1980 a modified pipe connection with

17.4 mm 00 (formerly 16 mm) i s installed. For this
connection and the former pipe connection, socket
617 589 01 09 00 is valid.

The socket 617 589 00 09 00 supplied up to now can

be refinished as required by machining the 10 to
17.7 mm. Then change part number of wrench to
617 589 01 09 00.

A. Engine 61 5, 616, 61 7 M-injection pump with pneumatic governor and

M/RSF-injection pump with mechanical governor

Removal

1 Clean injection pump on coupling nuts of injection

lines and on pipe connections.

2 Unscrew injection lines, clamping jaws or locking

plate and pipe connection.

3 Remove compression spring, copper sealing ring

and pressure valve with pressure valve carrier.

4 Flush suction chamber of injection pump by

actuating manual delivery pump. Remove foreign
particles, if any.
Installation

5 Clean pressure valve and pressure valve carrier, pay

attention to easy operation and damage.

6 Insert pressure valve carrier (6) with ring groove in

downward direction, pressure valve (4) and new
copper sealing ring (5).

M-injection pump
7 Mount compression spring (3) on pressure valve. 1 Pipe connection
2 Rubber sealing ring
3 Compression spring
4 Pressure valve
5 Copper sealing ring
6 Pressure valve carrier

8 Slightly lubricate pipe connection and screw in

with new rubber sealing ring (2).

9 For perfect seat of copper sealing ring (5), tighten

pipe connection as follows:

Tighten pipe connection t o 30 Nrn and release

again. Tighten once again to 30 Nm and also release
again.
MIRSF-injection
Then tighten to 35 Nm. 1 Pipe connection
2 Rubber sealing ring
3 Compression spring
4 Pressure valve
5 Copper sealing ring
6 Pressure valve carrier

10 Mount injection lines and clamping jaws or

locking plate and vent injection system (07.1-140).

11 Run engine, check for leaks and quiet idle speed.

B. Engine 616, 61 7 MW-injection pump with mechanical governor

Note

In the event of leaks between pipe connection and

element connection proceed as follows:

a) Pipe connection with ring groove on hex head

Replace rejected pipe connection only.

b) Pipe connection without ring groove on hex head

Replace all 5 pipe connections, even if only a single

pipe connection i s leaking.

A Pipe connection without ring groove

B Pipe connection with ring groove

Start of production: Pipe connection (B) with ring

groove engine 616 @model year 1977 starting begin
of production.

Engine 617 starting November 1975. l njection pump

production date 531.

Removal

1 Clean injection pump on coupling nuts of injection

lines and on pipe connections.

2 Unscrew injection lines and pipe connection.

Attention!
Do not loosen element connection (21,since other-
wise a basic adjustment of injection pump on injection
pump test bench will be required.

3 Remove compression spring, copper sealing ring

and pressure valve with pressure valve carrier.

4 Flush suction chamber of injection pump by

actuating manual delivery pump. Remove foreign
particles, if any.
Installation

5 Clean pressure valve and pressure valve carrier,

check for easy operation and damage.

6 lnsert new copper sealing ring (5) under pressure

valve carrier (6). l nstall pressure valve carrier (6) with
ring groove in downward direction. Mount pressure
valve (4) and compression spring (3) again.

1 Pipe connection
3 Compression spring
4 Pressurevalve
5 Copper sealing ring
6 Pressure valve carrier

7 Slightly lubricate pipe connection (1) on threads,

screw in and tighten in one step to 40-50 Nm.

8 Mount injection lines and vent injection system

(07.1-140).

9 Run engine, check for leaks and quiet idle speed.

07.1-215 Replacing diaphragm of injection pump, adjusting compensating path
(engine 615, 616 M-injection pump with pneumatic governor)

Special tool

Holder for dial gauge

Conventional tool

e.g. made by Mahr, D-7300 Esslingen

Dial gauge A 1 DlN 878
Order no. 810

Replacing diaphragm of injection pump

1 Disconnect connecting rod on tickler and start and

stop cable control.

2 Unscrew governor cover and remove together with

governor spring. Make sure that governor spring and
the compensating washers are not falling out when
removing governor cover.

3 Remove diaphragm by unscrewing large governor

cover. Remove cotter pin with washer from control
rod.

4 Remove diaphragm, while paying attention to

installed parts 1-4.

5 Remove parts 1-4 from removed diaphragm and

insert into new diaphragm.

1 Compensating bolt
2 Compensating washer for
compensating spring preload
3 Compensating spring
4 Compensating washer for
compensating path
5 Sleeve
6 Diaphragm
Adjusting compensating path

6 Measure compensating path. For this purpose,

insert hex screw M 6 (3) through diaphragm sleeve
(4) and compensating bolt (2). Place diaphragm on a
tubular base (5) with max 35 mm OD, min 22 mm ID
and min 10 mm in length. Then position holder of
dial gauge in such a manner that the feeler pin (1 )
rests on center of compensating bolt (2).

1 Feeler pin of dial gauge

2 Compensating bolt
3 Screw M 6
4 Diaphragm sleeve

7 Set dial gauge under preload to zero, then push

compensating bolt (2) down.

Engine Nominal value

615.912 = 1.1 mm
615.913 = 1.2 mm
616 = 1.1 mm

If required, adjust compensating path by adding or

removing compensating washer (4) (Fig. item 5).

8 For installation proceed vice versa.

07.1-220 Replacing vacuum box on injection pump
-.

Note

On injection pumps with mechanical or automatic

altitude adjusting box do not unscrew upper governor
cover, since otherwise an adjustment of the altitude
box on injection pump test bench would be required.

A. MW-injection pump in model 1 15.1

Removal

1 Unscrew rear governor cover and swivel sideways,

so that the connecting rod disengages from control
rod.

2 Unscrew vacuum box from governor cover. Two

screws are inserted from inside and one from outside.

Installation

3 Remove upper governor cover.

4 Screw vacuum box with new gasket and new copper

sealing ring to governor cover.

5 Mount rear governor cover with new gasket. Make

sure that the connecting rod of the vacuum box en-
gages in control rod (check through opening of upper
governor cover).

6 Mount upper governor cover with new gasket.

B. MW-injection pump in model 123.1

Removal

1 Unscrew lower righthand fastening screw (arrow).

2 Check position of control rod. Push guide lever on

cylinder head cover to stop while measuring position
of control rod. For this purpose, insert plug gauge
through bore against control rod and mark position
of plug gauge.

Attention!
On injection pumps with automatic altitude adjusting
box the position of the control rod cannot be checked
by means of a plug gauge. Since the plug gauge will
not make contact with control rod but with rocker
of altitude adjusting box.

3 Remove vacuum box after loosening the three

fastening screws.

lnstallation

4 Screw vacuum box with two new gaskets ( 1 ) to

governor cover.

Make sure that the connecting rod of the vacuum box

engages in control rod.

1 Gasket
2 Steel ring
5 To make sure, subsequently check control rod
position once again as described in item 2. The mark
on plug gauge should again be in alignment.

C. M/RSF-injection pump in model 123.1

Removal

1 Unscrew both fastening screws.

2 Slightly raise vacuum box, tilt toward the rear in

direction of engine and remove.

lnstallation

3 Check O-ring for damage and replace, if required.

4 Push emergency stop lever (arrow) to stop and

engage connecting rod of vacuum box in rocker of
emergency stop lever.

5 Mount fastening screws while paying attention to

correct seat of fastening plates.
07.1-225 Replacing altitude adjusting box

A. Mechanical altitude adjusting box engine 61 7 @ model year 1975176

Note

Any damage on altitude correction instrument can be

repaired only on an injection pump test bench with
injection pump removed.

Operation

The mechanical altitude adjusting box is a manually

adjustable altitude correction instrument which
restricts the full load control path.

The altitude correction provides no parallel displace-

ment of control path, which means that during an
adjustment of the altitude correction the max possible
control path i s restricted by means of a fixed stop.
This will make compensation inoperative and the
control path remains constant throughout entire speed
range.

The correction screw can be adjusted stepwise from

0-approx. 3,900 m ( 12,000 ft), each step amounting
to approx. 650 m (2,000 ft).

Recommended adjustments:
Up to approx. 650 m (2,000 ft) = position 0
from 650 m (2,000 f t ) - 2,000 m = position 1,300 m
(6,000 f t ) (4,000 f t )
from 2,000 rn (6,000 ft) - = position 2,600 m
3,200 m ( 10,000 ft) (8,000 f t )
from 3,200 m (10,000 f t ) = position 3,900 m
( 1 2,000 ft)
B. Automatic altitude adjusting box engine 616, 617 @starting model year 1977 and @

Starting model year 1977

Operation

With increasing altitude above normal (decreasing air

pressure) the two diaphragm boxes (12) will expand.
Starting from a given atmospheric pressure the inter-
nal force of diaphragm box will become higher than
the preload of the altitude box pretensioning spring
(11 ). Pushrod (10)will move in direction "a". As a
result, slotted lever ( 7 ) will be lifted from stop (6)
by means of a lever in direction "b" and lever (3)
will move in direction "c" (refer to lefthand cutout
of drawing).

Since the control lever ( 4 ) is coupled with lever (3)

by means of a pin, the control lever (4) and thereby
control rod (9) will move in direction "d" so that less
fuel will be injected. The more the adjusting lever (1)
is adjusted in direction of idle (stop), the more will
pin (5) of lever (3) move toward pivot point (8).

Adjusting lever
Adjusting lever shaft
Lever
Regulating lever
Pin
Stop
Slotted lever
Pivot
Control rod
Pushrod
Altitude box pretensioning
spring
Diaphragm box

As a result, adjustment during partial load will be in

direction of less and will move to almost O-adjustment
in idling position. At low altitudes above normal alti-
tude gate lever (7) will form a concentric circle around
adjusting lever shaft (2),so that the governor proce-
dure will not be corrected.
Note

The upper governor cover on injection pump can no

longer be screwed off, since the connecting rod in
governor is mounted together with altitude adjusting
box.

Replacing automatic altitude adjusting box

w---~ - ~ ~ ~~ - -

1 Apply counterhold to altitude adjusting box on

hex head ( 1 ) and loosen coupling nut (2).

2 Unscrew altitude adjusting box. Use any washers

remaining from removed altitude adjusting box, if
required.

3 Mount new altitude adjusting box with washers.

The venting pipe should be at the lowest point so
that condensate, if any, can flow out.
 07.1-230 Removal and installation of injection nozzles (injectors)

Tightening torques Nrn

lnjection nozzles 70-80

Injection lines 25

Special tools

Torque wrench 112" square,

40-130 Nrn

Torque wrench 1 /2" square,

15-65 Nm

Box wrench insert open, 1 7 mm, 112"

square for injection lines

Socket 27 mm, 112" square

for injection nozzle

Removal

1 Unscrew injection lines.

2 Pull off fuel hoses for leak oil and closing plugs of
4th or 5th injection nozzle.

3 Unscrew injection nozzles by means of socket. If

a threaded ring of prechamber comes loose, retighten
all threaded rings (05-117).

4 Remove nozzle plates.

5 Complete visual checkup of prechamber. For this

purpose, illuminate with a flashlight and check whether
ball pin i s in order.

50 Threaded ring
51 Prechamber
52 Sealing ring
53 Nozzle plate
80 Nozzle holder combination
81 Pencilelement glow plug
Installation

6 For installation proceed vice versa. Use only

resilient nozzle plates from now on. Pay attention
to tightening torques.

Attention!
Resilient nozzle plate may be used only once.
 07.1-235 Removal and installation of fuel pump
--

Removal

1 Unscrew all fuel connections.

2 Remove fuel pump after loosening both fastening

nuts.

3 Clean fuel pump. Replace suction and pressure

valves or replace fuel pump.

Installation
-
4 Mount fuel pump with new gasket.

5 On M-injection pumps with pneumatic governor,

correct oil level in injection pump. For this purpose,
unscrew filter (2) on injection pump and add engine
oil up to check bore ( 1 ).

6 Mount fuel connections and vent injection system

(07.1-1 40).

7 Check fuel pump (07.1-145).

07.1-240 Removal and installation of injection timer

Test values

End play of intermediate gear shaft 0.05-0.12

Tightening torques Nm

Hex nut for injection timer 70

Hex bolt for injection timer 40

Fastening screw for camshaft sprocket 80

Special tools

Impact puller for slide rail bolt

(basic unit)

Threaded bolt M 6, 50 mrn long &

llOOL-636e
116589013400

Threaded bolt M 6, 150 mrn long 11658902 3400

Holder

90
Note,

97
Fastening of injection timer changed.
95

let version
109
Injection timer is attached to intermediate 110
gear shaft by means of a nut (95) and a
102
ground washer (97).

94
2nd version
98
Injection timer is attached to interme-
diate gear shaft by means of a hex screw
(95) M 10 x 45.
103

3rd version

Models 123.1 25 (sedan long) and 123.183 (T-sedan)

with increased additional load are provided with a
double diaphragm vacuum pump. The double dia-
phragm vacuum pump is driven via a toothed cou-
pling sleeve, attachment and lubrication are by means
of a hollow hex screw (95).

Attention!
Do not mix up the different hex screws and injection
timers.

Adjusting range of injection timer changed from

6" t o 7.5".

A yellow dot outside on housing serves for identifica-

tion.

This injection timer i s also installed on engines

617.95 (turbodiesel).

On former engines with filament glow plugs the

injection timer (7.5' adjusting range) may not be
installed to prevent damage t o glow plugs.
Removal

1 Remove radiator (20-420).

2 Unscrew suction and pressure line from vacuum

pump and remove vacuum pump from cylinder crank-
case.

3 Unscrew fastening nut or hex screw of injection

timer.

4 Remove cylinder head cover.

5 Unscrew fastening screw for camshaft sprocket

(3).

3 Camshaft sprocket 9 Slide rail

4 Slide rail 10 Slide rail
8 Lock screw

6 Rotate crankshaft in direction of rotation of

engine to TDC mark.

Camshaft must be in alignment with marking of com-

pensating washer and 1 s t camshaft bearing (arrow).
7 Mark meshing point of chain on injection timer
and position of injection timer in relation to crank-
case with paint.

8 Remove chain tensioner or push back pressure pin

(05-310).

9 Remove slide rail (4) after removing hex screw.

10 Remove camshaft sprocket, while paying atten-

tion to compensating washer between camshaft and
camshaft sprocket. Leave chain on camshaft and
place together into chain box.

11 Unscrew lock screw (8) for chain drive and pull

out upper bearing pin of slide rail (10) by means of
puller.

3 Camshaft sprocket 9 Slide rail

4 Slide rail 10 Slide rail
8 Lock screw

12 Lift chain from injection timer. For this purpose,

slip holder in-between injection timer and chain. For
better location, introduce guide pin (arrow) into
threaded bore.

13 Remove or push off injection timer.

Attention!
Do not rotate crankshaft and camshaft following
removal of injection timer.

14 Remove bushing (2) for injection timer and thrust

ring (3) from intermediate gear shaft.

Injection timer lntermediate gear shaft

Bushing Woodruff key
Thrust ring
15 Check slide rails (9 and 10) (visual checkup) and
replace, if required.

Installation

16 Lubricate thrust ring (3) and bushing (2) and

slip on intermediate gear shaft. Pay attention to
correct seat of both Woodruff keys (5) (Fig. item 14).

Note: If an injection timer must be replaced, place

used injection timer on new injection timer in such
a manner that the splines of both injection timers
are in alignment. Then transfer painted mark on old
injection timer on new injection timer.

17 Slip injection timer on intermediate gearshaft.

9 Slide rail
10 Slide rail

18 Pull chain in upward direction or lift camshaft

sprocket with chain, making sure that the markings
of injection timer and cylinder crankcase are in align-
ment. If required, rotate injection timer until the
markings of injection timer and cylinder crankcase
are in alignment. Then pull out holder.

19 Slip camshaft sprocket with chain mounted on

camshaft, making sure that the marking of the com-
pensating washer is in alignment with marking of first
camshaft bearing.
Check again whether all markings are in alignment,
similar to removal and TDC position on balancing
disc.

20 Install chain tensioner (05-310).

21 Introduce bearing pins of slide rail (10) into

cylinder crankcase (Fig. item 5). Coat bearing pin at
end with sealing compound. When knocking-in, make
sure that the locking wire of the slide rail engages in
notch of bearing pin.

22 Screw in lock screw (8) with new sealing ring and

tighten (Fig. item 30).

23 Check begin of delivery and adjust, if required

(07.1-110 and 115).

24 Vent injection system (07.1-140).

25 Mount hex nut and ground washer or hex screw.

Attention!
Use only specified ground washer, part no. 615 990
03 40.

26 Check end play of intermediate gear shaft. Should

be 0.05-0.12 mm, touch up thrust ring (3), if required.
27 Mount fastening screw for camshaft sprocket
and tighten to 80 Nm.

28 Check injection timer for function. For this pur-

pose, turn hex nut or hex screw to the right up to
stop by means of a wrench. Upon release, injection
timer should return automatically to i t s old position.

29 Mount vacuum pump with new gasket and con-

nect vacuum lines.

30 Introduce slide rail (4) with holder into bore of

outer slide rail (5) and tighten.

3 Camshaft sprocket
4 Slide rail
8 Lock screw
9 Slide rail
10 Slide rail

31 Mount cylinder head cover, while paying attention

to correct seat of rubber gasket.

32 Mount regulating linkage, check and adjust, if

required (30-300).

33 Install radiator andconnectall lines.

34 Run engine and check for leaks.

07.1-245 Replacing fuel filter

A. Model 1 15.1

Note

Vent injection system following assembly of fuel

filter (07.1-140).

1st version
1 Screw M 12 x 35
2 Washer
3 Holder
4 Stud M 12

2nd version
3 Holder
5 Screw M 8 x 45
6 Washer
7 Stud M 8

Start of production for 2nd version

Model Starting chassis end no.

0. Model 123.1

Removal

1 Loosen fastening screw ( 1 ) and remove housing

with filter element in downward direction.

1 Fastening screw
2 Hollowscrew

Installation

2 Mount new filter element with housing (3) and

gasket (4).

3 Filter element with housing

4 Gasket

3 Upon assembly of fuel filter, vent injection system

(07.1- 140).
14-450 Removal and installation of intake pipe, replacement of gasket

Removal
-- -- -

1 Remove air cleaner or scoop.

2 Disconnect regulating linkage.

3 On engine 615, 616 with choke control, unscrew

vacuum lines.

Engine 615,616

4 On engines without choke control, unscrew support

on intake pipe.

Engine 615,616

Note: Engine 61 7 is also provided with a support on

intake pipe.

Installation: February 1979

Engine starting engine end no.

manual transmission 074930

617.912
automatic transmission 06871 9

Model starting chassis end no.

Engine 61 7
5 Remove cylinder crankcase breather.

6 Remove exhaust system (49-100).

7 Loosen fastening nuts and remove intake pipe

together with exhaust manifold.

8 Clean intake pipe and check flange surfaces

with straightedge, touch up on surface plate, if
required.

Installation

9 For installation use new gasket and proceed

vice versa.

10 Adjust regulating linkage (30-300).

11 Run engine, check intake system for leaks by

spraying with Iso-Oktan DlN 51756 or benzine.

12 Adjust idle speed (07.1-100).

I ntake system
Engine 615,616

1 Vacuum line to vacuum pump 5 Choke control 9 Intake pipe

2 Hollow screw 6 Nut 10 Gasket
3 Sealing ring 7 Washer 11 Closing plug
4 Vacuum line to injection pump 8 Gasket 12 Sealing ring
Engine 615,616,617

1 Vacuum line to vacuum pump 1) 6 Intake pipe engine 61 5,616 12 Screw

2 Hollow screw 7 Intake pipe engine 61 7 in model 11 5.1 13 Washer
3 Sealing ring 8 Intake pipe engine 61 7 in model 123.1 14 Nut
4 Strut engine 615, 616, 617 9 Vibration mount 15 Nut
5 Washer 10 Gasket
5a Nut 1 1 Gasket

1) not with piston pump.

14-470 Removal and installation of exhaust manifold

Removal
- .,,. .

1 Removeairfilteror hood.

2 Disconnect throttle linkage.

3 On engine 615,616 with choke control, unscrew

vacuum lines.

Engine 6 1 5 , 6 1 6

4 On engines without choke control, unscrew

support on intake manifold.

Engine 6 1 5 , 6 1 6

Note: Engine 617 i s also provided with a support on

intake manifold.

Start: February 1979

-

starting engine
Engine end No.

manual transmission 074930

617.912
automatic transmission 068719

starting chassis
Model
end No.

Engine 61 7
5 Remove cylinder crankcase breather.

6 Remove exhaust system (49-100).

7 Loosen fastening nuts and remove intake manifold

together with exhaust manifold.

lnstallation

8 For installation proceed vice versa, using a new

gasket.

9 Adjust throttle linkage (30- 300).

10 Run engine, check intake system by spraying

with Iso-Oktan D I N 51 756 or benzine for leaks.

11 Adjust idlespeed (07.1- 100).

Exhaust manifold
Model 1 15.1 (except 1 15.1 14)

Model 115.1 14

Model 123.1 Lefthand and righthand steering

I For vehicles with engine 6 1 5 and 616

II For vehicles with engine 61 7
 15-505 Operation of preglow system

A. General

On a diesel engine, combustion is effected by self-

ignition of the fuel sprayed into the highly compressed
and thereby highly heated combustion air.

In a cold engine, the self-ignition temperature is not

attained by compression alone. A preglow system is
therefore required, which serves the purpose of
increasing the temperature of the compressed air
to facilitate starting of the cold engine by the inflam-
mation of fuel particles on filament of glow plug.

The duration of preglowing (preheating) depends on

temperature of engine and on ambient temperature.

B. Glow plug design

a) Filament-type glow plugs

The filament-type glow plugs are essentially compris-

ing the plug body (5)with threads M 18 x 1.5, one
center electrode with filament wire and the outer
electrode. The current is carried by conductor (1) or a
connecting cable, depending on location of plug, to
center electrode (13) or t o ring element (3) of outer
electrode ( I 1). The center electrode (13) and the outer
electrode (11) are connected to each other by means
of the glow filament (6). The two electrodes are in-
sulated in relation to each other by the insulating
compound (12) and in relation to the plug body (5)
by the insulation compound (4).

In addition, a plastic insulator (2) is installed at upper

end of glow plug between outer and center electrode.
The connection insulator (10) insulates the two current
connections. The domed washer (8) installed in insula-
tor serves as a lock for nut (7).

1 Conductor 8 Domed washer

2 Plastic insulator 9 Sheet-metal cap on
3 Ring element (on connection insulator
outer electrode) 10 Connection insulator
4 Insulation compound 1 1 Outer electrode
5 Plug body 12 Insulating compound
6 Glow filament 13 Center electrode
7 Nut
The life of a glow plug depends to a considerable
extent on the condition of the injection nozzle
and the combustion sequence. Injection pressures
which are too low, binding nozzle needles, coked
and dripping nozzles as well as a too early begin
of injection may result in early breaking of
filament. In addition, oil carbon bridges may lead
to a ground connection and subsequent burning of
filament.

If a glow plug i s burnt out, i t i s absolutely

necessary to check the glow plug which comes next
in circuit, since a short-circuit between the threaded
stem ( 1 1 and the outer pole (2) or the outer pole
and cylinder head by metallic foreign particles
or soot i s possible. In addition, any residue in
threaded bore of cylinder head must be removed.

The temperature of the glow filament during pre-

heating may amount to approx. 900-1000 OC. The
combustion temperature of the engine at operating
temperature amounts to approx. 800 OC. Temperatures
above 900 O C during continuous operation will
shorten the life of glow plugs. The glow plugs have
an input of approx. 60 amps at a voltage drop of
approx. 0.9 volt per glow plug. They are connected
in series with resistance conductors.

b) Quick-start pencil element glow plugs

The quick-start pencil element glow plugs are

essentially comprising a housing with M 12 x 1.25
threads and a heater rod pressed into housing.

The single-pole connecting pin i s screwed to housing

by means of a round brass nut which cannot be
released.

The pencil element glow plugs are designed for a

voltage of 11 volts and are operated in parallel.
The heater element comprises a heating and control
coil connected in series.

1 Control coil
2 Heater coil

When the glow system i s switched on, a current of

approx. 30 amps will flow per glow plug.

The heater coil heats the glow plug very quickly.

The control coil increases i t s resistance with increasing

temperature and restricts the current to approx.
14 amps. This will protect the glow plug against over-
load.

b Current curve of quick-start pencil element glow plug

After a glow period of 9 seconds, a pencil element

temperature of 900 " ~ / 1 6 5 2"F is attained, after 30
seconds the max. temperature of 1180 " ~ / 147 2 " F.

b Temperature curve of quick-start pencil element glow plug

C. Preglow system with glow plug resistance control engine 615,616 in model 115.1

Operation

The mechanical-electrical preglow start and stop

switch i s a pull-push switch with four switch
positions: stop position, drive position, preglow
position and start position. In addition, the
preglow start and stop switch is provided with a
lock so that the key can be pulled off only in
stop position.

Stop position

In stop position the knob of the pull-push switch

is completely pushed in and the adjusting lever
on injection pump is moved into full forward
position by means of the Bowden wire. In this
position of the adjusting lever the control rod is
in "stop" position, the pistons of the elements are
at zero delivery, the engine receives no more fuel
and will stop. In this position, the terminals 19,
50 and 17 are de-energized. The key on steering lock
can be pulled off.

Drive position

In drive position, the Bowden wire with the oblong

eye in relation to adjusting lever is located in
such a manner that the eye i s not resting against
bolt of adjusting lever so that the adjusting lever
i s not actuated. When pulled out of stop position,
the knob engages in the next following detent for
the drive position. Terminals 19, 50 and 17 are
de-energized. The key on steering lock cannot be
pulled out.

Preglow position

After pulling knob out of drive position into preglow

position, a small resistance will be felt. In this
position, the switch must be held in place until
the preglowing is completed.
I n this position, terminal 19 i s energized, glow
plugs ( 1-4) will begin to glow via glow plug
resistance control (5). Terminals 50 and 17 are
de-energized.

1-4 Glow plugs and resistors

5 Glow plug resistance control
6 Preglow starter switch
a Tosteeringlock
b T o starter

When preglowing is completed, the knob is pulled

complete1y up to stop after overcoming the minor
resistance and is held in place until the engine
fires.

In start position, the bolt of the adjusting lever

rests against eye and is pullig the adjusting lever
completely to the rear.

This will push the control rod beyond the full

load stop and the injection pump will inject the
starting fuel.

I n starting position, terminals 50 and 17 are

energized. The starter begins to function via
terminal 50.

The glow plugs remain energized also in starting

position via terminal 17.

To prevent the voltage drop on glow plugs from

becoming too high during starting, the glow plug
resistance control is bypassed.

When the knob of the pull-push switch i s released,

the switch will automatically return into driving
position under the influence of springs.

1 - 4 Glow plugs and resistors

5 Glow plug resistance control
6 Preglow starter switch
a To steering lock
b To starter
D. Preglow system with preglow indicator lamp engine 61 5,616 in model 123.1

Operation

The preglow system is

switched on by pulling
preglow starter switch
into position I. The
preglow indicator lamp
lights up as long as
preglowing continues.

The glow plugs are

connected in series and
protected by a 50 amps
fuse.

1-4 Glow plugs and

resistance bars
5 Fuse and reed contact
6 Preglow indicator lamp
7 Preglow starter switch
a Tosteeringlock Lvi
b T o starter

The preglowing current of approx. 50-60 amps i s

determined by the firm resistances of the glow
plugs, as well as by the resistance conductors.

Too high a preglowing current is the result of a

ground connection or short-circuit in preglow
system, e. g. a defective glow plug.

Too low a preglowing current is the result of

transition resistance caused e. g. by a loose glow
plug connection or by an insufficiently charged
battery.

The preglowing time depends on the ambient tempera-

ture and the coolant temperature and can be set at
will. For the cold engine, the following preglowing
periods are reference values:

Ambient temperature +20 O C approx. 10 seconds

Ambient temperature 0 O C approx. 20 seconds
Ambient temperature - 5 O C approx. 30 seconds

A t lower temperatures pertinently longer up to

max 1 minute.

Temperature OC
Glow period at 52 amps
The preglow indicator lamp lights up as long as
the preglow system i s actuated. It i s contacted
with plus by means of the reed contact located in
parallel with fuse. The reed contact is closed i f
the available glow current i s adequate. Minus of
indicator lamp is continuously connected to ground.

The engine i s stopped by pushing preglow starter

switch down.

Mechanical speed increase is effected by turning

knob on preglow starter switch.

Turning counterclockwise = higher speed

Turning clockwise = lower speed

1 Start and stop control 3 Clamp

2 Bowden wire for idle 4 Fuse
speed adjuster
E. Preglow system with ready-for-starting lamp engine 61 5,616 in model 123.1

Operation

The preglow system i s switched on by pulling preglow

starter switch into position I. The ready-for-starting
condition of engine i s indicated by an indicator
lamp in instrument cluster. The glow plugs are con-
nected in series and protected by a 50 amps fuse.

The preglow current of approx. 55 amps i s determined

by the firm resistors of the glow plugs, as well as
the resistance conductors.

1 Steering lock switch 5 Glow plugs

2 Preglow starter switch 6 Thermo time switch
3 Fuse box a To battery
4 Preglow indicator lamp b To starter

The reason for an excessively high glow current i s

a ground connection or short-circuit in the preglow
system, e. g. a defective glow plug.

The reason for a too low glow current is a transfer

resistance, e. g. a loose plug connection or an in-
sufficiently charged battery.
The preglowing time i s indicated in dependence of

In preglow position and in starting position (I and

II) of preglow starter switch the preglow indicator
lamp is contacted with plus by means of a reed
contact connected in parallel with fuse and closed
if adequate glow current is available. The preglow
indicator lamp is connected to minus by way of the
rest contact in thermo time switch.
A t the end of the optimal preglow period the contact
in thermo time switch opens. The preglow indicator
lamp is extinguished and thereby shows that the
engine is ready for starting.

F. Preglow system with key start system engine 61 7 in model 1 15.1

Operation

When the steering lock starter switch is actuated,

in position "2" (preglowing start), the preglow
system is switched on by the preglow time relay.
The extinguished preglow indicator lamp in instru-
ment cluster shows that the engine i s ready for
starting.

The glow plugs are started in series.

The preglow current of approx. 50-55 amps i s de-

termined by the firm resistors of the glow plugs and
the resistance conductors.

Too high a preglowing current i s the result of a

ground connection or short-circuit in preglow system,
e. g. a defective glow plug.

Too low a preglowing current i s the result of

transition resistance caused e. g. by a loose glow plug
connection or by an insufficiently charged battery.

The preglow time relay is attached to pedal assembly

behind instrument cluster.
The preglow time relay has an integrated power
relay (a) for preglow current, a control relay (b)
for switching off power relay, an electronic
component (c) for the safety circuit and a reed
contact (d) as overload protection.

I n key position "2" terminal 4 of preglow time

relay ( 1 ) i s contacted via terminal 15 of steering
lock starter switch (4) and the winding of power
relay (a) via the rest contact of control relay (b)

The contacts of the power relay are closing the

preglow circuit. From B+ the preglow current flows
via terminals 5 and 6 of preglow time relay ( 1)
across the glow plugs and the thermo time switch
(6)to ground. The preglow system is in operation.

1 Preglow relay 5 Glow plugs with

2 Preglow indicator lamp resistance conductors
3 Rotary light switch 6 Thermo-time switch
4 Steering lock starting switch 7 Plug connection
The preglow time is indicated by the preglow
indicator lamp.

In dependence of the coolant temperature and the

preglow current flowing across the thermo time
switch, the proglow indicator lamp is contacted
with minus by the closed contact in thermo time
switch. In parallel with the glow plugs, the
control lamp is connected to plus by a line
connected to the glow plug of the 5th cylinder.
When the optimal preglow time is obtained, the
contact in thermo time switch will interrupt
minus and the preglow indicator lamp i s extinguished.
The engine is now ready for starting.

In starting position the preglow time relay is

contacted by terminal 50 of the steering lock
starter switch via terminal 3. Control relay (b)
i s energized. The contacts are closing (inter-
rupting the rest position) and remain closed via
terminal 4 i n a self-holding circuit.

The power relay (a) is not switching off, since

during the starting operation the power relay is
directly contacted via terminal 3. The preglow
system remains switched on (refer to wiring diagram).

A t end of starting operation the key moves back

into position "2" (preglowing, drive).

The power relay switches off, since there is no

voltage neither via terminal 3, nor via the inter-
rupted rest contact of the control relay which
remains switched on via terminal 4.

The preglow system is now in disconnected condition.

Attention !
I f the engine is not started when the preglow indi-
cator lamp i s extinguished, the preglow system
remains switched on up t o 90 + 20 seconds of
preglow time.

When working in engine compartment, note that in

such a case the resistance conductors are red hot.

After 90 + 20 seconds the safety relay is energized

for a short moment by control relay (b). The con-
trol relay attracts and remains switched on under
self-holding condition. The rest contact is inter-
rupted and disconnects the voltage at power relay
(a). As a result, the contacts of the power relay
will interrupt the preglow current. The preglow
system is now inoperative.

The engine is shut off by turning key to position "1 "

or "0".

The steering lock has an attached valve which is

actuated by way of a cam when the key is turned.
A vacuum box on injection pump i s provided with a
vacuum and the regulating rod of the injection pump
is pulled to "stop".
 G. Preglow system with key start system engine 615,616,617 in model 123.1

Operation

When the steering lock starter switch is actuated

in position "2" (preglowing, start) the preglow
system i s switched on by the preglow time relay.
The extinguished preglow indicator lamp in instru-
ment cluster shows that the engine is ready for
starting. The glow plugs are started in series and
protected with a 50 amps fuse.

The preglow current of approx. 50-55 amps i s de-

termined by the firm resistors of the glow plugs
and the resistance conductors.

Too high a preglowing current is the result of a

ground connection or short-circuit in preglow
system, e. g. a defective glow plug.

Too low a preglowing current i s the result of

transition resistance caused e. g. by a loose glow
plug connection or by an insufficiently charged
battery.

The preglow time relay is attached to instrument

cluster on pedal assembly.

The preglow time relay has an integrated power

relay (a) for preglow current, a control relay (b)
for switching off power relay, an electronic
component (c) for the safety circuit and an
electronic component (d) with a primary reed
contact for the preglow indicator lamp.
In key position "2" terminal 4 of preglow time
relay ( 1) i s contacted via terminal 15 of steering
lock starter switch (3) and the winding of power
relay via the rest contact of control relay (b).

The contacts of the power relay are closing the

preglow circuit. From B+ the preglow current flows
across terminal 5 and 6 of preglow time relay ( 1 ) via
fuse (8) and the glow plugs t o ground.

Wiring diagram engine 615,616

1 Preglow time relay 6 Plug connection

2 Rotary light switch 7 Glow plugs with
3 Steering lock starting switch resistance conductors
4 Temperature sensor 8 Fuse box
5 Preglow indicator b T o starter terminal 50

For preglowing, the preglow indicator lamp is switched

by means of an electronic component in preglow time
relay. A temperature sensor (NTC) in coolant circuit
changes i t s resistance (cold = high, warm = low resis-
tance) in dependence of coolant temperature and
activates the electronic component. After attaining the
required preglow time, the preglow indicator lamp is
switched off.

The optimal preglow period is indicated when the

preglow indicator lamp goes out.
 b a r s . .

Wiring diagram engine 61 7

1 Preglow time relay 4 Temperature sensor 7 Glow plugs with resistance conductors
2 Rotary light switch 5 Preglow indicator lamp 8 Fuse box
3 Steering lock starting switch 6 Plug connection b To starter terminal 50

In starting position the preglow time relay is

contacted by terminal 50 of the steering lock
starter switch via terminal 3. Control relay (b)
is energized. The contacts are closing (inter-
rupting the rest position) and remain closed via
terminal 4 in a self-holding circuit.

The power relay (a) is not switching off, since

during the starting operation the power relay is
directly contacted via terminal 3. The preglow
system remains switched on.

A t end of starting operation the key moves back

into position "2" (preglowing, drive). The power
relay switches off, since there i s no voltage neither
via terminal 3, nor via the interrupted rest contact
of the control relay (b) which remains switched on via
terminal 4. The preglow system is now in
disconnected condition.
Attention!
I f the engine is not started when the preglow indi-
cator lamp is extinguished, the preglow system
remains switched on up to 90 + 20 seconds of pre-
glow time.

When working in engine compartment, note that in

such a case the resistance conductors are red hot.

After 90 + 20 seconds the safety relay i s energized

for a short moment by control relay (b). The con-
trol relay attracts and remains switched on under
self-holding condition. f he rest contact i s inter-
rupted and disconnects the voltage at power relay
(a). As a result, the contacts of the power relay
will interrupt the preglow current. The preglow
system i s now inoperative.
 H. Quick-start preglow system engine 615, 616, 617.91 in model 123.1

General

The essential components of the preglow system are

the quick-start pencil element glow plugs, the preglow
time relay and the preglow indicator lamp.

Wiring diagram

1 Preglow time relay

a Power relay
b Electronic unit
c Temperature sensor (NTC resistor)
d Reed relay
e To starter terminal 30
f To fuse box terminal 15
g To plug connection starter lockout
backup lamp switch terminal 5 0
4 Preglow indicator lamp
G 1 - G 5 Pencil element glow plugs

Note: On engine 61 5, 616, the pencil element glow

plug G 5 is no longer installed.
Quick-start pencil element glow plugs

The quickstart pencil element glow plugs are designed

for a voltage of 11 volts and are operated in parallel.

Preglow time relay

The preglow time relay i s located in engine compart-

ment at the left on wheelhouse.

After removing protective cap, the electric connec-

tions, as well as the 80-amp fuse are accessible.

The former temperature sensor in coolant circuit is

no longer installed. Instead, the relay temperature or
relay-ambient temperature is obtained by means of
an NTC resistor in preglow time relay.

Functions of preglow time relay

The preglow time relay comprises the following func-

tions:

- Switching of glow current

- Ready-for-start indicator

- Safety shutoff

- Fault indicator
If the key i s turned to position "3" (start), the power
relay (a) remains attracted, activated by terminal 50.
The glow period continues until the key is turned
back to position "2".

Ready-for-start indicator

A temperature sensor installed in preglow time relay

obtains the glow period.

When the glow system is switched on, the preglow

indicator lamp in instrument cluster will light up.

If the required glow period, in dependence of the

ambient temperature of the preglow time relay, is
attained, the preglow indicator lamp goes out and
thereby indicates the ready-for-starting condition.

a Preglow period
Safety shutoff

If there is no start within 20-35 seconds following

indication of ready-for-startingcondition, the glow
current is interrupted by the safety shutoff. If another
s t a r t follows, the glow system i s again switched on for
the duration of the starting period.

The safety shutoff is no longer a fixed condition. It is

determined by the time up to ready-for-startingcon-
dition (preglow indicator lamp goes out) plus 20 to
35 seconds.

a Preglow period
b Safety shutoff

Fault indication

A fault in preglow system is indicated if the preglow

indicator lamp i s not lighting up when the key is
actuated in position "2".

The following faults are indicated:

- lnterruption of line to connection terminal 30.

- 80-amp fuse defective.

- Power relay in preglow time relay defective.

- lnterruption of one or more lines to pencil

element glow plugs.

- lnterruption of one or more pencil element

glow plug.
Nob: If tolerances of pencil element glow plugs or of
Reed relay (d) are unfavorable, response of fault
indicator only if two pencil element glow plugs are
defective is acceptable.

Faults are indicated (pencil element glow plug resis-

tance control) by comparing the current of pencil
element glow plug GI with current of remaining
pencil element glow plugs G2-G5 (or G2-G4) con-
nected in parallel.

The currents of the two lines to the pencil element

glow plugs GI and G2 up to G5 (or G2-G4) are
rooted through two Reed relay coils with different
numbers of windings connected opposite to each
other.

If the current flow in both coils is the same, the

magnetic fields will cancel each other and the Reed
contact will not respond.

If the balance of the magnetic field is interrupted by

the loss of one or several pencil element glow plugs,
the Reed contact will close and the electronic system
(b) will be activated.

The preglow indicator lamp switches off immediately

and will therefore not light up when the preglowing
begins.
 15-510 Checking preglow system
-
~ ~- -- . - ....

Conventional tools
--

Voltmeter (measuring range 0-3 volts/O-16 volts)

- - -- - - - --

Ammeter (measuring range 0-60 amps)

Note

Battery charged min 60 % (acid density approx.

1.22 glcc).

A. With glow plug resistance control engine 615,616 in model 115.1

a) Preglow system not preglowing

This complaint indicates an interruption in circuit

of preglow system.

Set voltmeter to measuring range 0-16 volts. Connect

plus cable of voltmeter to input (threaded stud) of
glow plug of 4th cylinder and minus cable to ground.
Actuate preglow system and read voltage on volt-
meter.

If voltmeter indicates 12 volts, the interruption

i s located at glow plugs or their connections.

I f the voltmeter indicates 0 volt, look for inter-

ruption at preglow starter switch or on glow plug
resistance control.

1. Checking glow plugs for interruption

Connect minus cable of voltmeter to ground. Check

voltage at current input and output of the 4 glow
plugs by means of plus cable of voltmeter.

If a glow plug at current input shows 12 volts and

at output 0 volt, the respective glow plug is inter-
rupted and must be exchanged.
2. Checking pmglow stamr switch and gkw pbg
r e d m n a control

Connect minus cable of voltmeter to ground. By

means of the voltmeter plus cable the connections of
the preglow starter switch should indicate the
following values:

In switch position 0 (key in steering lock in position

"2") on terminal 15/54 = 12 volts.

In switch position I (preglow position) on terminal

19 = approx. 11 volts.

Preglow starter switch

In switch position II (starting position) on terminal

17 and on terminal 50a = approx. 11 volts.

I f the voltage on terminal 15/54 = 0, check line to

steering lock switch or steering lock switch as well as
connection.

If the voltage on terminal 19, 17 or 50a = 0, ex-

change preglow starter switch.

G b w plug msistance control

Voltage at glow plug resistance control input and

output approx. 11 volts.

If voltage is 0, the line or the glow plug resistance

control is interrupted and line or control must be
replaced.

b) Preglw system glows too s l w l y or too fast

In the event of such a complaint, the current flowing

through the preglow system is too low as a result of
transfer resistances or too high as a result of a
short-circuit.

First measure glow current with ammeter.

For this purpose, connect ammeter at connection of

glow plug cy tinder 4.

Glow arrant in p r q b w position: eppmx. 50-55 amps.

Measured after 15 seconds (battery charged min
60 %I.

I f this glow current i s not attained, measure voltage

drop in preglow system by means of voltmeter.

Check connections for tight seat.

2,O-2,6

a T o glow plug position control

I f this glow current is exceeded, a short-circuit

in preglow system i s indicated (glow plugs, preglow
starter switch, preglow resistance control).

I f a glow plug fails as a result of a short-circuit,

measure glow current once again after replacing
glow plug.

B. With preglow indicator lamp engine 615,616 in model 123.1

a) PregDow system not prqlswiragi

This complaint i s based on an interruption in current

circuit of preglow system.

Attention!
The preglow system is fused, check fuse. (The
separate fuse box is mounted on front wall inside
engine compartment).
Adjust voltmeter, measuring range 0-16 volts.
Connect plus cable of voltmeter t o input (threaded
stud) of glow plug of 4th cylinder and minus cable
of voltmeter to ground. Actuate preglow system and
read voltage on voltmeter.

I f voltmeter indicates 12 volts, the interruption

i s at glow plugs or their connections.

I f voltmeter indicates 0 volt, the interruption is

at preglow starter switch or i t s connections.

1. Checking glow plugs for interruption

Connect minus cable of voltmeter to ground. Check

voltage at current input and output of the four
glow plugs by means of plus cable. I f 12 volts are
measured at input of a glow plug and 0 volt at
output, the respective glow plug is interrupted and
must be replaced.

2. Checking pmglsw starter switch and connections

Connect minus cable of voltmeter to ground. The

following values must be measured at connections
of preglow starter switch with plus cable of volt-
meter:

In switch position 0 (key in steering lock in

position "2") on terminal 15/54 = 12 volts.

I n switch position I and II (preglow or start

position) on terminal 19 and 50a = approx. 11 volts.
I f the voltage at terminal 15/54 = 0 volt, check
line to steering lock switch or steering lock switch
itself, as well as the respective connection.

I f the voltage at terminal 19 and 50a = 0 volt,

replace preglow starter switch.

b) Pregbw system pmglowing too slowly or too fast

Nominal time at: +20 O C approx. 12 seconds

- 5 "C approx. 30 seconds

Glow period at 52 amps Temperature OC

In the event of this complaint, the current flowing

through preglow system i s too low as a result of
transfer resistances, or too high as a result of a
short-circuit.

First, measure glow current with ammeter.

For this purpose, connect ammeter at glow plug

connection of cylinder 4.

Glow current in pmglow position: approx. 50-55 amps.

Measured after 15 seconds (battery charged min 60 %).

I f this glow current is not attained, measure voltage

drop in preglow system with voltmeter.

Check connections for tight seat.

 2,O -2,6

a To fuse

If this glow current i s exceeded, a short-circuit

in preglow system is indicated (glow plugs, preglow
starter switch).

If a glow plug i s lost as the result of a short-circuit,

exchange plug and measure glow current once again.

c) Preglow systm~gbws, but pmgbw indicator lamp

not isrdicatisrgs

Connect voltmeter to connection LA of fuse box (5)

and to ground. Actuate preglow system and read
voltage on voltmeter.

If voltage indicates approx. 12 volts, check bulb and

feed lines of preglow indicator lamp (pay attention
to tight seat of bulb in socket).
 If voltmeter indicates 0 volt, measure preglow
current.

If approx. 50-55 amps are measured, the reed contact

of the fuse box is defective and the fuse box must
be replaced.

If a low glow current is measured, a transfer

resistance in preglow systernis indicated or the battery
is insufficiently charged.

Check connections of glow plugs for tight seat and

recharge battery, if required.

C. With ready-for-starting lamp engine 615,616 in model 123.1

a) Pregbw system not pregbwing

This complaint i s based on an interruption in current

circuit of preglow system.

A-ntion!
Preglow system is fused. Check fuse. (The separate
fuse box i s mounted on front wall of engine
compartment).

Set voltmeter to measuring range 0-16 volts. Connect

plus cable of voltmeter to input of glow plug of
4th cylinder and connect minus cable to ground.
Operate preglow system and read voltage on voltmeter.

I f voltmeter indicates 12 volts, look for fault on glow

plugs or their connections.

If voltmeter indicates 0 volt, look for fault on

preglow starter switch or i t s connections.

1. Check glow phgs for intemption

Connect minus cable of voltmeter to ground. Check

voltage with plus cable of voltmeter a t current
input and current output of the four glow plugs.

If 12 volts are measured at current input of a glow

plug and 0 volt at output, this glow plug is inter-
rupted and must be replaced.
2. Checking preglow starter switch and connections

Connect minus cable of voltmeter to ground.

Measure the following values with plus cable of
voltmeter at connections of preglow starter
switch:

In starter position 0 (key in steering lock in

position "2") on terminal 15 = 12 volts.

I f voltage at terminal 15 = 0 volt, check line to

steering lock switch or steering lock switch itself
as well as the respective connection.

Voltage in switch position I and II on terminal 19

and 50a = approx. 11 volts.

I f voltage on terminal 19 and 50a = 0 volt, replace

preglow starter switch.

b) Pmglsw system preglows too slow or too fast

Nominal time at: +20 O C approx. 12 seconds

- 5 O C approx. 30 seconds

-30 -2'0 -i0 20 + i 0 + 2 0 +30 +iO +50 +& +70 +80 +go

Glow period at 52 amps Temperature OC

This complaint i s caused by insufficient current
flowing through preglow system as the result of
transfer resistances, or too much current as the
result of a short-circuit.

Measure glow current first with ammeter.

For this purpose, connect ammeter to connection of

glow plug for cylinder 4.

Glow current in prqlow position: approx. 5 0 5 5 amps.

Measured after 15 seconds (battery charged at least

60 %).

I f this glow current i s not attained, measure

voltage drop in preglow system with voltmeter.

Check connections for tight seat.

a Tofuse
b To preglow indicator lamp

I f this glow current is exceeded, a short-circuit

in preglow system is indicated (glow plugs, preglow
starter switch) .

I f a glow plug i s lost by a short-circuit, measure

glow current once again after replacing plug.
c) Pmglow system glows, but preglow indicator
lamp not indicating

Connect voltmeter to connection LA of fuse box (3)

and to ground. Actuate preglow system and read
voltage on voltmeter.

If voltmeter indicates approx. 12 volts, check bulb

and feed line of preglow indicator lamp (pay atten-
tion to tight seat of bulb in socket).

Pull coupler from thermo time switch and connect

directly to ground. Actuate preglow system. If
preglow indicator lamp lights up, replace thermo
time switch.

If voltmeter indicates 0 volt, measure preglow

current.

If approx. 50-55 amps are measured, the reed

contact of fuse box is defective and the fuse box must
be replaced.
I f the glow current measured i s too low, a transfer
resistance in preglow system i s indicated or the
battery is insufficiently charged.

Check connections of glow plugs and preglow starter

switch for tight seat and recharge battery, if
required.

D. With key start system engine 617 in model 1 1 5.1

a) Prggbw system not pmglowing

This complaint is the result of an interruption in

circuit of preglow system.

Adjust voltmeter to measuring range 0-16 volts.

Connect plus cable of voltmeter to input of glow
plug of 5th cylinder and connect minus cable to
ground. Turn key on steering lock starter switch
to position "2" and read voltage on voltmeter.

If voltmeter indicates 12 volts, look for interruption

on glow p\ugs or their connections.

If voltmeter indicates 0 volt, look for interruption

at prqlow time relay or its connections.
1. Checking glow plugs for interruption

Connect minus cable of voltmeter to ground. Check

voltage with plus cable of voltmeter a t current
input and output of the five glow plugs.

If 12 volts are measured at current input of a glow

plug and 0 volt a t output, this glow plug is
interrupted and must be replaced.

2. Checking preglowing time relay and its connection

Turn key of steering lock starter switch to position

"2".

Pull coupler from preglow time relay. Connect minus

cable of voltmeter to socket 1 of coupler. Check
socket 5 and 4 one after the other with plus cable
of voltmeter. If voltmeter indicates each time 12
volts, replace preglow time relay.

If voltmeter indicates 0 volt, connect minus cable

of voltmeter to ground. Check at socket 5 of volt-
meter with test cable.

If voltmeter indicates 12 volts, line 31 to socket 1

i s interrupted.

If voltmeter indicates 0 volt, line 30 to socket 5

i s interrupted.

Then check socket 4 with plus cable of voltmeter.

If voltmeter indicates 0 volt, line 15 to socket 4

is interrupted.

In the event of complaints, check lines or connections

for a loose contact.
b) Pmgkw system pmglows too slowly or too fast 0)

'+
V)
,-
F

Nominal time at: +20 O C approx. 12 seconds

- 5 O C approx. 30 seconds

This complaint i s caused by insufficient current

flowing through preglow system as a result of
transfer resistances or too much current as the
result of a short-circuit.

-30 -20 -10 20 +10 +20 +30 +40 +SO +60 +70 t80 +90

Glow period at 52 amps

Temperature OC

Measure glow current with ammeter first. For this

purpose, connect ammeter to connection of glow
plug for cylinder 5.

Glow eorrmnt in preglow position: 50--55 amps.

Measured after approx. 15 seconds (battery charged

at least 60 %).

If this glow current i s not attained, measure voltage

drop in preglow system with voltmeter.

Check connections for tight seat.

a To fuse
b To preglow indicator lamp
Attention!
When checking the voltage, connections of glow plugs,
as well as the resistance conductors may not be
shorted against ground (screwdriver against engine
block), since this may lead to failure of preglow
time relay.

I f this glow current is exceeded, a short-circuit on

preglow system is indicated.

If one of the glow plugs i s lost by a short-circuit,

change glow plug and measure preglow current once
again.

c) Pregkw sydern glows, preglow indicator lamp

not indicating

1. Check line from glow plug cylinder 5 to preglow

indicator for interruption.

2. Check bulb of preglow indicator lamp in instrument

cluster (pay attention to tight seat of bulb in
socket).
E. With key starting system engine 615, 616,617 in model 123.1

Preglow sys@m in general

Glow plugs are connected in series. The current flows

across glow plugs from cylinder (5-) 4-3-2-1 t o
ground. Each glow plug is designed for a voltage of
0.9 volt at a max. current of 63 amps.

For this reason, the glow plugs are connected t o

resistance conductors, on which the remaining voltage
i s consumed (drops). The resistance conductors will
also become red hot during preglowing.

The extent of the preglow current is determined by

the total resistance in the preglow system (glow plugs
plus resistance conductors).

Consequently, the cores for a burnt-out glow plug or

a defective fuse under influence of an excessively
high current flow can never be the preglow time relay.
In such cases there is a reduction of total resistance in
preglow system (e. g. short circuit to ground of one or
several glow plugs by coking or by contact with pre-
chamber.

A ground short on glow plug results in varying effects

in preglow system. A glow plug ground short of the
4th or 5th cylinders, for example, will immediately
make the fuse defective, while in the event of a glow
plug ground short of the 3rd cylinder, the glow plug
of the 4th cylinder will burn out (perhaps after several
preglowing operations, as the case may be). Therefore,
in the event of a burnt-out glow plug, always test the
prior glow plug for a ground short and replace, if
required.
a) Preglow system not preglowing

This complaint is caused by an interruption in current

circuit of preglow system.

For accurate determination of fault source (whether

glow bulbs or other components), connect voltmeter
(measuring range 0-30 volts) to current input of glow
plug of 4th or 5th cylinder and to vehicle ground and
read voltage (preglow system engaged).

Readout approx. 12 volts = interruption at glow plugs

including connections (but not at preglow time relay).

Readout 0 volt = fuse defective, preglow time relay

or activation of relay defective.

1. Check glow plugs for interruption

Connect negative cable of voltmeter t o ground. Check

voltage by means of positive cable of voltmeter con-
nected to current input and output of 4 or 5 glow
plugs (while disconnecting ground of glow plugs on
1s t cylinder).

I f 12 volts are measured at current input of a glow

plug and 0 volt at output, this glow plug is inter-
rupted and must be replaced.
Attention !
Never short connections of glow plugs or resistance
conductors against ground (e. g. screw driver against
engine block); this may result in failure of preglow
time relay!

2. Testing preglow time relay and connections

Pull coupler from preglow time relay. Connect nega-

tive cable of voltmeter to vehicle ground. Check
voltage at jack 5, 4 and 3 one after the other by means
of positive cable, at jack 3, the starter should be
actuated.

Then connect negative cable of voltmeter to jack 1

and positive cable t o jack 5 and measure voltage.

Nominal values

Jack 5 = approx. 12 volts (terminal 30, continuous

voltage)
Jack 4 = approx. 12 volts (terminal 15, preglow
system engaged)
Jack 3 = approx. 12 volts (terminal 50, while starting)
Jack 1 = approx. 12 volts (terminal 31, negative line)

I f 0 volt is measured at one of the jacks, test respective

line for interruption or repair interruption.
If 12 volts are measured on all jacks, the preglow
time relay is defective, replace preglow time relay.

Wiring diagram

1 Preglow time relay 6 Line connector (engine harness)

2 Rotary light switch 7 Glow plugs and resistance conductors
3 Steering lock starting switch 8 Fuse
4 Temperature sensor a T o battery
5 Ready-f or-starting indicator b T o starter
b) Preglowing system glowing too slowly or too fast

Nominal time at: + 20 " ~ 1 6 "8F approx. 12 seconds

- 5 " ~ 1 2 3" F approx. 30 seconds

Preglowing system preglows too slowly because not

enough current can flow through transition resistances
in glow plugs or on connections.

Preglowing system preglows too fast because too

much current flows through one or several glow plugs
due to ground short.
-30 -2b -lb t0 +lo +2b +4bI+50 + 6 0 +TO
+$ +a0 +90

Temperature "C

These faults can be found by measuring voltage drop of

each glow plug. Measure voltage on glow plugs a t
current input and output with test points of volt-
meter (measuring range 0-3 volts).

Engine 6 1 5 , 6 1 6
a To fuse

Engine 6 1 7
a To fuse
Attention!
Measure as close as possible to glow plug, since other-
wise measuring faults (higher voltage drop) will show
up by including the resistance conductors into measur-
Ing.

When measuring, pay attention t o risk of short circuit!

c) Preglowing system preglows, preglow indicator

not lighting up or not going out

If the preglow indicator lamp is not lighting up, pull

coupler from temperature sensor - indicator lamp
should now light up. In such a case, replace tempera-
ture sensor.

I f the indicator lamp is not lighting up, pull coupler

from preglow time relay and bridge jack 5 (terminal
30) with jack 7. If the indicator lamp is now lighting
up, replace preglow time relay. If indicator lamp i s
not lighting up, check bulb or renew, or repair line
interruption.

I f the preglow indicator lamp is not going out after

attaining ready-for-starting condition, connect coupler
of temperature sensor t o ground. If indicator lamp is
now going out, the temperature sensor is interrupted
and should be replaced. I f the indicator lamp is not
going out, the preglow time relay is defective or the
line to relay is interrupted. Replace preglow time
relay or repair line interruption.
Note: The temperature sensor can be tested with an
ohmmeter.

Resistance values according to coolant temperature:

0 "C/O "F = approx. 8500 ohms

+25 " ~ 1 7 7O F = approx. 2500 ohms
1 "F = approx. 300 ohms
+80 " ~ 176

At readout of 0 ohm, the temperature sensor has a

short circuit, at readout 0" ohm, the temperature
sensor i s interrupted and should be replaced.
F. Quick-start preglow system engine 615, 616,617.91 in model 123.1

Wiring diagram

1 Preglow time relay

a Power relay
b Electronic unit
c Temperature sensor (NTC-resistor)
d Reed relay
e T o starter terminal 3 0
f T o fuse box terminal 1 5
g To plug connection starter lockout and
backup lamp switch terminal 5 0
4 Preglow indicator lamp
G 1 - G 5 Pencil element glow plugs

Note: On engine 61 5,616, pencil element glow plug

G 5 is not required.

1. Test bwlb and its line

Complaint:

Preglow indicator lamp not lighting up when pre-

glowing system is switched on, in spite of ready-for-
starting condition.
Rernedy:

Pull 4-point coupler from preglow time relay, turn

key into position "2", bridge jack 1 and 3 for coupler.

If preglow indicator lamp is not lighting up, check

bulb or renew, if required.

If bulb i s in order, check black line from coupler of

jack 3 of preglow time relay up to preglow indicator
lamp for interruption, repair interruption.

If preglow indicator lamp is lighting up, the preglow

time relay i s defective and should be replaced.

2. Test main current circuit of preglow system for

interruption

Complaint:

Preglow indicator lamp not lighting up, engine cannot

be started.
Remedy:

Measure voltage at terminal 30 of preglow time relay

against ground by means of voltmeter.

If no voltage i s indicated, check red line from starter

terminal 30 up t o preglow time relay terminal 30 for
interruption, and, repair interruption, if required.

If voltage i s indicated (approx. 12 volts), test 80-amp

fuse for tight seat or interruption and renew, i f
required.

I f so far no fault has been found, test voltage at jack

1 of 4-point coupler of preglow time relay against
ground.
I f no voltage is indicated with preglow system
switched on, test blacklblue-green line from fuse box
terminal 15 up to coupler jack 1 of preglow time
relay for interruption and repair interruption, if
required.

If voltage is indicated (approx. 12 volts), connect

voltmeter to jack 1 (terminal 15) and jack 4 (terminal
31 ) and test voltage (should be approx. 12 volts).

If no voltage is indicated, test brown line from jack 4

to ground for interruption and repair interruption,
i f required.

If so far no fault has been found, preglow time relay

is defective, replace preglow time relay.

3. Test pencil element glow plugs and their lines

Complaint:

Preglow indicator lamp not lighting up, engine firing

poorly, one or several pencil element glow plugs or
their lines to pencil element glow plugs may be inter-
rupted.

Complaint:

Preglow indicator lamp lighting up, engine firing

poorly after attaining ready-for-starting condition,
a pencil element glow plug or a line to pencil element
glow plugs of cylinders 2-4 (2-5) may be interrupted.
Pull 6-point coupler from preglow time relay.

Measure resistance against ground (engine block) by

means of ohmmeter one after the other as follows:

Jack 1 of coupler = pencil element glow plug cylinder 1

Jack 2 of coupler = pencil element glow plug cylinder 2
Jack 3 of coupler = pencil element glow plug cylinder 3
Jack 4 of coupler = pencil element glow plug cylinder 4
Jack 5 of coupler = pencil element glow plug cylinder 5

-
If resistance is measured, the respective pencil ele-
ment glow plug or supply line or connection may be
interrupted.

If measured resistance is smaller (e. g. a t 20 " ~ 1 6 O8F

< 1 ohm), the supply line and the pencil element glow
plug is in order.

Note: It i s possible that (as the result of unfavorable

tolerances) the indicator lamp will indicate a fault
only after 2 pencil element glow plugs in cylinders
2-5.

To make sure that the fault indication in preglow

time relay i s not defective, disconnect 2 pencil ele-
ment glow plugs of cylinders 2-4 (2-5) in such a
case and repeat preglow procedure.

If warning lamp now indicates a fault (not lighting up),

the preglow time relay is in order.
15-512 Damage on filament-type glow plugs and its cause

1. Filament wire torn (hair crack)

Cause:

Start of delivery too early or damaged nozzles

(dropping, hanging).

2. Filament wire burnt oat or scorched

(wire Mack or brown)

Cause:

Overheated while driving by damaged nozzles

(dropping, hanging), begin of delivery too early or oil
in combustion area (e. g. caused by leaking vacuum
pump or damaged valve stem seal).

Note: I f a filament wire is burnt out, always test

prior glow plug. Also pay attention to deposits in
glow plug bore. If coked, clean glow plug bore with
reamer 617 589 00 53 00.
3. Filament wire burnt down (wire grey)

Cause:

a) Ground short on glow plug stem (outer pole,

arrow) caused by coked glow plug bore (remedy
by reaming glow plug bore in cylinder head).
Ground short by distored conductor resting
against throttle linkage (for example at full load).

b) Preglow time relay not switching off after starting

(test preglow time relay).

4. Glow plug stem burnt out (arrow)

Cause:

a) Coolant in combustion area through damaged

cylinder head seal or crack in cylinder head.

b) Water in fuel, if all glow plugs are showing the same

damage pattern.

c) Oil in combustion area caused by leaking vacuum

pump, damaged valve stem seal or excessively high
engine oil level (e. g. considerable internal leaking
of injection pump with engine circulation lubrica-
tion).
5 . Ground short between glow plug stern and
housing

Cause:

Oil carbon, as the result of predominating short-

distance operation, excessively early begin of delivery
or metallic particles (e. g. chips).
 ................................................................ ............ ............................................................ .................................... ..

15-515 Removal and installation of glow plugs

..

f ightening torque Nrn

-

Glow plugs 50
- -

Special tools
- --

Box wrench

Reamer 11004- 8589 617 589005300

Removal

1 Unscrew all nuts, remove connecting line,

connection insulators and conductors.

2 Unscrew glow plugs with box wrench.

3 Prior to installing glow plugs, clean glow plug

channels and bores in prechambers with reamer. For
this purpose, f i l l flutes of reamer with grease and
ream glow plug channels.

Note: I n the course of time, oil carbon will settle

in glow plug channels. This may result in a ground
connection of glow plugs.

4 After reaming glow plug channels, crank engine

several times with starter motor, so that the
residue is blown out of combustion chamber.

5 lnstall glow plugs, connect to conductors,

connect connection cable and attach with nuts.

7 Check glow plugs for function.

15-520 Adjustment of cable control
-

Adjustment

1 Push start and stop control into stop position.

2 Unscrew adjusting screw (6) until steering lock

switch is released. Then unscrew by an additional
1 to 1 1/2 turns and counterlock adjusting screw.

1 Preglow starter switch 4 Cap nut M 10

2 Steering lock switch Part no. 001 587 01 00 01
3 Cable control 5 Start and stop control
6 Adjusting screw

3 Check adjustment.

Attention!
If the preglow starter switch is in driving position,
actuation of key in steering lock switch should not
be possible.
15-535 Removal and installation of prqlow starter switch with cable control
- P.....

A. Model 11 5.1

Removal

1 Remove instrument cluster.

2 Unscrew pull knob and rosette and pull preglow

starter switch ( 1 ) into range of combination
cutout.

3 Unscrew cable control (3) from steering lock

switch (2).

4 Loosen start and stop control (5)to injection

pump on preglow starter switch and disconnect.

5 Pretension cable control with cap nut (41,

disconnect on preglow starter switch and unscrew.

6 Disconnect electric lines.

1 Preglow starter switch 5 Start and stop control

2 Steering lock switch 6 Adjusting screw
3 Cable control
4 Cap nut M 10
Part no. 001 587 01 00 01

7 For installation proceed vice versa.

Connection of electric lines:

Color redlblack Terminal !% 2.5 mm2
Color purplelwhite Terminal 50a 2.5 mm2
Color purplelwhite Terminal 17 4 mm2
Color purple /blue Terminal 19 4 mm2
0. Model 123.1

Removal

1 Remove start and stop control on injection pump

and Bowden wire for idle speed adjuster on guide
lever at cylinder head cover.

2 Remove pull-push knob on instrument panel. For

this purpose, insert a wire through bore of pull-push
knob and press off cover.

3 Unscrew hex nut and remove pull-push knob.

4 Unscrew fastening nut on instrument panel and

pull out preglow starter switch with Bowden wires
in downward direction.

Attention!
Avoid buckling of Bowden wires.

5 Remove Bowden wires.

a) Remove start and stop control ( 1 1. For this pur-

pose, force off lock (4).

b) Remove Bowden wire for idle speed adjuster (2).

For this purpose, remove clamp ( 3 ) ,unscrew wire
coil, l i f t slightly and pull out.

1 Start and stop control 3 Clamp

2 Bowden wire for idle 4 Lock
speed adjuster

6 Unscrew cable control (4) on steering lock

switch (2).
7 Disconnect electric lines and remove preglow
starter switch.

8 For installation proceed vice versa.

Connection of electric lines:

Color redlblack Terminal 15/54
Color purple Terminal 19
Color purplelwhite Terminal 50
18-005 Oil circuit, oil pressure, pressure relief valve and oil filter

A. Model 1 15.1

Oil circuit

1 Oil pump 6 Pressure relief valve 11 Oil pipe

2 Oil filter 7 Intermediate gear shaft C1 Oil return flow front
3 Bypassfilter element 8 Worm gear for oil pump C2 Oil return flow bore rear
4 Main flow filter element 9 Camshaft bearing sprocket end C3 Oil return flow via throttle
5 Overflow valve filter element 10 Chain tensioner of bypass filter into oil pan

Air oil cooler and thermostat in oil filter

Engine with air oil cooler thermostat in oil filter

61 5.91 2 up to chassis end No. 400248 -

616 general -

61 7 general general
Oil pressure

A t operating temperature, the oil pressure at idle may

drop to 0.5 bar gauge pressure (0.5 atij). During accel-
eration, the oil pressure should rise again immediately
and should attain at least 3 bar gauge pressure (3 a t i i )
at 3000/min.

Opening pressures of pressure relief valves bar gauge pressure (atii)

Bypass valve - filter element 3.5 (3.5)

Bypass valve - air oil cooler 1.5 (1.5)

Pressure relief valve in main oil duct front engine 615 5.0 (5.0

Pressure relief valve on oil pump engine 616,617 8.0 or 7.0 (8.0 or 7.0 atu)

Thermostat - oil filter engine 617 "C

Begin of opening 95 -+ 4

Fully opened 110*4

Pressure re1ief valve

On engine 615, the pressure relief valve is screwed in

or on, respectively, main oil duct at engine face and
on engines 6161617 at oil pump.

If there is no oil pressure or if the oil pressure is too

low, check whether oil pressure relief valve on oil
pump has dropped or become loose.
In both cases, coat threads of oil pressure relief valve
with sealing compound, part No. 002 989 94 71 and
screw-in.

Bypass valve in oil filter

The bypass valve (11) opens when the difference in

pressure between the dirty side and the clean side of
f i lter exceeds 3.5 bar gauge pressure.
This will happen when the filter element is heavily
contaminated. The oil will then flow to engine in un-
cleaned condition.

2 Closing plug with sealing ring

3 Connection for oil pressure gauge
11 Star valve (overflowvalve - filter element)
12 Compression spring
Oil filter

The main and bypass filter elements are separately lo-

ca ted.
During first inspection (500-1000 km), replace ini-
tial operation filter element with filter cartridge ( 4 )
and main flow filter plate element (3).

Then replace filter cartridge during oil change every

5000 km.

1 Filter t o p
2 Sealing r i n g
3 M a i n f l o w f i l t e r element
4 Bypass filter element
5 Compression spring w i t h
spring retainer
6 Filter b o t t o m
7 Sealing r i n g
8 Hex. b o l t

Clean main flow filter plate element with holding pli-

ers 1 10 589 00 68 00 in benzine.
Operation

Engines 615 and 616

Coming from feed duct (a), the oil flows into oil filter
housing. The major portion of the oil flows through
main flow filter element (4) and via duct (b) into main
oil duct and to the bearing points. The remaining oil
flows from outside through bypass filter element (6)
where i t is finely filtered and from there across a
groove in hex. bolt (10) through throttle bore (d)
back into oil pan.

Engine 6 1 5
1 Filter t o p
2 Closing plug w i t h sealing r i n g
3 Connection f o r o i l pressure gauge
4 Main f l o w f i l t e r element
5 Sealing r i n g
6 Bypass filter element
7 Filter b o t t o m
8 Comprersion spring w i t h spring retainer
9 Sealing -ing
10 Hex, b v l t
11 Star valve ( o v e r f l o w valve - f i l t e r element)
12 Compression spring
a Uncleaned o i l t o f i l t e r
b Cleaned o i l t o lube points
c Cleaned o i l f r o m bypass filter element i n t o
o i l pan
d T h r o t t l e (also installed o n engines 61 6, 61 7.91 1
Engine 616

Starting at a differential pressure of approx. 1.5-1.7

bar, the oil will flow directly to main and bypass filter
element.

Below approx. 1.5-1.7 bar differential pressure, the

bypass valve (11) will close. The oil will now flow via
air oil cooler to main and bypass filter element.

Engine 616
1 Filter t o p
2 Screw c o n n e c t i o n w i t h sealing r i n g (uncleaned o i l
t o o i l cooler)
3 Connection f o r o i l pressure gauge
4 M a i n f l o w f i l t e r element
5 Sealing r i n g
6 B y pass f i l t e r element
7 Filter b o t t o m
8 Compression spring w i t h spring retainer
9 Sealing r i n g
10 Hex. b o l t
1 1 Star valve (bypass valve - air o i l cooler)
12 Compression spring
1 3 Closing p l u g w i t h sealing r i n g
14 Screw c o n n e c t i o n w i t h sealing r i n g (uncleaned
o i l f r o m o i l cooler)
15 Closing p l u g w i t h sealing r i n g
16 Star valve ( o v e r f l o w valve - f i l t e r element)
17 Compression spring
b Cleaned o i l t o lube p o i n t s
c Cleaned o i l f r o m bypass f i l t e r element i n t o o i l pan

Engine 617

Starting at an oil temperature of approx. 9 5 O ~ ther-

,
mostat ( 13) begins displacing control valve ( 12).

In end position, the direct flow to main or bypass

filter element is closed except for a given quantity of
oi I.
This quantity of oil is enough to guarantee lubrication
of engine a t low outside temperatures when the
through-flow in oil cooler i s extensively prevented by
the viscosity of the oil.

The major portion of the oil flows to air oil cooler

and is cooled there, it will then flow back to oil filter
housing and through main and bypass filter element
to bearing points or oil pan.

Engine 617
1 Filter t o p
2 Closing p l u g w i t h sealing r i n g
3 Connection f o r o i l pressure gauge
4 M a i n f l o w filter element
5 Sealing r i n g
6 By pass f i l t e r element
7 Filter b o t t o m
8 Compression spring w i t h spring retainer
9 Sealing r i n g
10 Hex. screw
1 1 Compression spring
1 2 C o n t r o l valve
1 3 Thermostat
1 4 Screw connection w i t h sealing r i n g
(uncleaned o i l t o o i l cooler)
1 5 Screw connection w i t h sealing r i n g
(uncleaned o i l f r o m o i l cooler)
1 6 Closing p l u g w i t h sealing r i n g
1 7 Star valve ( o v e r f l o w valve - filter element)
18 Compression spring
b Cleaned o i l t o lube points
c Cleaned o i l f r o m bypass filter element i n t o o i l pan

When the filter element i s badly contaminated and the

differential pressure between the dirty and the clean
side of the filter exceeds 3.5 bar gauge pressure, the
bypass valve ( 17) will open. The oil will then flow to
engine in uncleaned condition.
B. Model 123.1

Oil circuit

1 Oil p u m p w i t h screwed-on 8 Chain tensioner

pressure relief valve 9 Camshaft bearing sprocket end
2 Oilfilter 10 O i l pipe
4 Pressure gauge 12 A i r o i l cooler
7 Intermediate gear shaft

On engines 616.912, starting February 1979, on ve-

hicles with air conditioning system, the air oil cooler
of version A has been replaced by version 0.

Air oil coolers of version B cannot be installed in ve-

hicles with version A.
Air oil cooler and thermostat in oil filter

Engine with air oil cooler and thermostat in oil filter

61 5 only on vehicles with air conditioning system

616 standard up to June 1978, starting July 1978 on

vehicles with air conditioning system only

6 17 general

Oil pressure

A t operating temperature, the oil pressure at idle may

drop to 0.5 bar gauge pressure (atu).
During acceleration, the oil pressure should immedi-
ately rise again and attain at least 3 bar gauge pressure
(atu) a t 3000lmin.

In the event of complaints about trembling of oil

pressure gauge needle, the throttle pin, part No. 123
542 00 74 can be installed in pressure gauge line a t
instrument end with tip first.

Pressure relief valves

Opening pressure of pressure relief valves bar gauge pressure (atu)

Bypass valve (8) in oil filter 3.5

Pressure relief valve on oil pump 7

Thermostat - oil filter engine 617 "C

Begin of opening 95 *4
Fully opened 110t4

Pressure relief valve on oil pump

The dampened oil pressure relief valve (7 bar gauge

pressure) is screwed to oil pump.
At no or insufficient oil pressure, check whether oil
pressure relief valve has dropped from oil pump or
has become loose.

In both cases, coat threads on oil pressure relief valve

with sealing compound, part No. 002 989 94 71 and
screw-i n.

Bypass valve in oil filter

The bypass valve (8) opens when the differential

pressure between the dirty and the clean side of the
filter exceeds 3.5 bar.

This will happen when the filter element i s badly con-

taminated. The oil will then flow to engine in un-
cleaned condition.

8 By pass valve
a from oil pump
b to main oil duct

Oil filter

The main and bypass filter element are combined in

a cartridge.

During the first insprection (500-1000 km), replace

initial operation filter element (1) with combination
filter element (2).

1 Initial operation oil

filter element
2 Combination filter element

Then replace combination filter element during oil

change every 5000 km.
Filter element (B), part No. 617 184 01 25 replaces
filter element, part No. 61 7 184 00 25 and can be in-
stalled in all diesel engines with upright oil filter.

On the other hand, do not install filter element, part

No. 61 7 184 00 25 in engine 61 7.950.

A Combination filter element

dimension a = 40 m m
B Combination filter element
dimension b = 55 mm
1 s t version

Up to October 1976, the oil filter cover has been at-

tached with a central bolt (1). The central bolt (1) is
simultaneously the return flow pipe for the fine-fil-
tered engine oil.

The central bolt has no check valve.

1 Central b o l t
8 By pass valve
16 Filter element
22 Header ptpe
24 Sealing r i n g

When changing the filter element, loosen central bolt

and pull out until the throttle bore (arrow) projects
about 5 mm above housing cover. As a result, the re-
turn flow duct in filter housing lower half will no
longer be closed by the central bolt and the engine
oil can flow back into oil pan.

2nd version

Starting November 1976, the oil filter cover is attached

by means of two nuts.

The return flow pipe (18) is pressed into cover and is

provided with a check valve (19).

When changing the filter element, unscrew cover (3)

and pull up for a given distance. As a result, the return
flow pipe (18) on cover will free a bore which con-
nects the ducts (b) and (c) with each other. The oil in
oil filter will flow into oil pan through duct (c).
Operation

The oil filter comprises the following main compo-

nents:

a) Oil filter housing with bypass valve, return flow

locking valve and thermostat.

b) Cover with return flow pipe, check valve and seal-

ing ring.

C) combination filter element.

1 Nut M 8 1 7 Valve seat r e t u r n f l o w

2 Stud M 8 locking valve
3 Cover 1 8 R e t u r n f l o w pipe
4 Sealtng r i n g 1 9 Check valve
5 O i l f ~ l t e housing
r 20 O-ring
6 Threaded connection 21 O-ring
6aThreaded connection 22 Header pipe
7 Compression spring 23 Connection f o r o i l pressure
8 Star valve gauge
9 Valve seat by pass valve A Uncleaned o i l t o air o i l
10 Compression spring cooler
1 1 Thermostat B Uncleaned o i l f r o m air o i l
1 2 C o n t r o l valve cooler
1 5 Compression spring a f r o m oil pump
1 6 Star valve b t o bearing p o i n t s
C f i n e f i l t e r e d o i l t o o i l pan
d o i l r e t u r n f l o w bore t o o i l
Pa n

Coming from feed duct (a), the oil flows through re-
turn flow locking valve (16 and 17) into oil filter hou-
sing and flows directly to combiantion filter element.

After flowing through combination filter element, the

oil, which has been cleaned in main flow filter element
(16a1, continues flowing through header pipe (22) and
duct (b) to main oil duct and on to bearing points.

On the other hand, the oil, which has been fine-filtered

in bypass filter section (16), flows through return
pipe ( 18) and duct (c) to oil pan.

To keep the main flow and the bypass flow separate,

a rubber seal is inserted in combiantion filter element.

a f r o m oil pump c f ine-f iltered o i l

b t o bearing points t o o i l pan
e o i l pressure gauge
Engine 617 and engines 615, 616 with air oil cooler

Starting at an oil temperature of approx. 9 5 ' ~the ~

thermostat (11) beginns displacing the control valve
(12), which will attain i t s end position at approx.
1 loOc.In the end position, the direct flow to combi-
nation filter element is closed except for a given quan-
tity of oil (g). This oil quantity is enough to guarantee
lubrication of engine at low outside temperatures,
when the through-flow in oil cooler i s considereably
detained by the now viscous oil.

The major oil quantity arrives at air oil cooler where

i t is cooled and then flows back to oil filter housing
and through oil filter housing from outside in.

The cleaned oil flows through header pipe (22) or re-

turn flow pipe ( 18) to bearing points or into oil pan.

A to air oil cooler c f ine-f iltered oil to oil pan

B from air oil cooler e oil pressure gauge
a from oil pump g oil quantity directly to
b to bearing points combination filter element

If the filter element is badly contaminated and the

differential pressure between the dirty and the clean
side of the filter exceeds 3.5 bar, the bypass valve
(8 and 9) opens. The oil will then flow to engine in
uncleaned condition.

The return flow locking valve (16 and 17) and the
check valve (19) in return flow pipe (18) prevent the
oil from oil filter flowing back into oil pan when the
engine is shut off for longer periods.
a from oil pump
b to bearing points
e oil pressure gauge
Complaints concerning oil filter

1 On oil filter 1st version, the oil may flow from oil
filter housing back into oil pan after an extended pe-
riod of inoperation of engine. As a result, the follow-
ing faults will occur:

a) Delayed indication of oil pressure by pressure

gauge.

b) Oil level in engine too high.

Note: Replacement of oil filter because of these com-

plaints is not justified, since in this connection any
fears concerning subsequent bearing damage are un-
founded. The lubrication of the bearing points i s
guaranteed by the residual oil in bearing points in
spite of a delayed response of the oil pressure gauge.

2 I f following a change of filter element an oil pres-

sure (0.5 atii) is indicated at idle speed, observe the
following:

Excessive force when inserting central bolt ( 1) during

a filter change may push the sealing ring (24) out of
its hold into a position in front of header pipe (22).
The oil will then be supplied via the overflow valve
(8) which will result in a drop in oil pressure. To avoid
pushing out sealing ring (24), insert central bolt (1)
into oil filter without using force.
Check pressing-in depth of riser pipe in oil filter.
Height of riser pipe from upper edge of pipe up to
contact surface of filter element should not exceed
41 + 1 mm. If the height exceeds 42 mm, renew com-
plete oil filter.
18-110 Removal and installation of oil filter
P

Tightening torques Nm (kpm)

Central bolt - oil filter cover (version 1 )

20-25 (2.0-2.5)
Nuts for oil filter cover (version 2)

Screws for oil filter on cylinder crankcase 30 (3)

Special tools

Torque wrench 318" square,

8-32 Nm (80-320 kpcm)

Box wrench open, 12 mm, 318" square 61 7 589 01 03 00

rek04-8562

Note

When the oil filter is removed, residue from gasket

may remain stuck to flange surface of cylinder crank-
case.

To prevent such residue from entering the clean oil

duct (arrow) of cylinder crankcase during removal
(e.g. by scraping), make sure to cover or close bores
first.

Removal

1 On 1 s t version, loosen central bolt and pull out for

approx. 50 rnm so that the oil can flow back into oil
pan. Throttle bore (arrow) should be visible.
On 2nd version, unscrew oil filter cover and pull up
for a short distance so that the oil can flow back to
oil pan.

2 Unscrew oil cooler lines (arrows). Apply counter-

hold to threaded connections for this purpose.

3 Unscrew oil pressure indicator with open box

wrench on oil filter.

4 Unscrew oil filter and remove.

5 Clean sealing surfaces on oil filter and cylinder

crankcase.

For this purpose, close bores on cylinder crankcase.

Installation

6 Position oil filter with new gasket and screw down.

7 Screw-on oil cooler lines.

8 Connect oil pressure indicator to oil filter.

9 Insert new oil filter element, if required.

10 Mount oil filter cover and screw down.

11 Run engine a t idle speed and check for leaks.

18-120 Checkingthermostatinoilfilter

Thermostat - oil filter OC

Begin of opening 95 + 4
- - - - - - -

Fully opened 110+4

Special tool

Telethermometer for measuring

engine oil temperature

Nose

The following engines are provided with a thermostat

in oil filter:

Engine 615 in model 123.1 on vehicles with air con-

ditioning system.

Engine 616 in model 123.1 generally up to August

1978 and starting August 1978 on vehicles with air
conditioning system only.

Engine 61 7 in model 11 5.1 and 123.1 generally.

1 Exchange oil dipstick for flexible heat sensor

2 Run engine at increased speed and watch telether-

mometer.

3 A t 95 f 4 " ~ a, clear rise of oil temperature on oil

cooler should be noticed (manually ).

If not, replace thermostat.

18-125 Removal and installation of thermostat in oil filter

Tightening torques Nm (kpm)

Central bolt for oil filter cover (1st version)

20-25 (2.0-2.5)
Nuts for oil filter cover (2nd version)

Valve seat ring in oil filter housing (model 123.1)

- 40 (4
Closing plug in oil filter housing (model 115.1)

Special tools

Torque wrench 318" square,

8-32 Nm (80-320 kpcm)

Socket 112" square for valve seat

ring

Box wrench open, 12 mm, 318" square

Note

The following engines are provided with a thermostat

in oil filter:

Engine 61 5 in model 123.1 on vehicles with air con-

ditioning system.

Engine 616 in model 123.1 up to August 1978 gen-

erally and starting August 1978 on vehicles with air
conditioning system only.

Engine 617 in models 115.1 and 123.1 generally.

Remove functioning thermostat only at temperatures

below 60°c, since otherwise the thrust pin (a) willbe
pushed out.

Never pull thrust pin (a) out of wax thermostat, since

otherwise proper function will not be guaranteed any
longer.
A. Engine 61 7 in model 115.1

Removal

1 Unscrew closing plug (arrow).

2 Remove thermostat with control valve and com-

pression spring.

Installation

3 Insert thermostat with control valve and compres-

sion spring.

4 Screw-in closing plug with new sealing ring

5 Check oil level

0. Engine 615, 616, 617 in model 123.1

Removal

1 Remove oil filter (18-110).

2 Unscrew valve seat ring ( 17) with wrench socket.

3 Remove start valve (16), spring retainer (13) and

compression spring ( 15).

4 Remove thermostat ( 1 1) with control valve (12)

and compression spring (10).

10 Compression spring 1 5 Compression spring

1 1 Thermostat 16 Star valve
12 Control valve 1 7 Valve seat ring
13 Spring retainer
Installation

5 lnsert thermostat (11) with control valve (12) and

compression spring (10).

6 Insert spring retainer ( 13), compression spring

(15) and star valve ( 16).

7 Position valve seat ring and tighten to 40 Nm

(4 kpm) with wrench.

8 Peen valve seat ring in both recesses on oil filter

housing (arrows) by means of a crosscut chisel.

9 Install oil filter with new gasket.

10 Correct oil level.

18-210 Removal and installation of oil pump

Tightening torques Nm (kpm)

M 12 40 (4
Oil drain plug to oil pan
M 26 50 (5)

Oil pan lower half to upper half 10 (1)

Special tools

Torque wrench handle 20-100 Nm (2-10 kpm) 001589352100

-
Torque wrench handle 50-200 Nm (5-20 kpm) 001 5 8 9 4 4 2 1 0 0

Plug-type ratchet 1/2" square for

torque wrench

Allen wrench 5 mm, 300 mm long

Note

As a spare part, the oil pump, part No. 115 180 13 0 1,

of engine 115 will be delivered for engines 615.91 21
9 13.

Removal

1 Drain engine oil.

2 Remove oil pan lower half.

3 Unscrew fastening screw on cy tinder crankcase

and on bearing cap.

4 Pull out oil pump.

Installation

5 For installation proceed vice versa.

1 8-215 Removal and installation of oil pressure relief valve

Tightening torques Nrn (kprn)

Oil drain plug to oil pan

Oil pan lower half to upper half 10 (1)

Oil pressure relief valve 40 (4)

Opening pressures of pressure relief valves bar gauge pressure (atii)

Pressure relief valve in main oil duct front (engine 61 5.9 121913) 5.0 (5.0)

Pressure relief valve on 011pump (engines 615.9401941, 616, 617.91) 7.0 (7.0)

Notes

The engines are provided with different oil pressure

relief valves:

On engines 61 5.912/913 the oil pressure relief valve

is installed in main oil duct, and on engines 615. 9401
941, 616 and 61 7 i t is screwed to oil pump.

On engines 616.916 and 61 7.910 differeni oil pres-

sure relief valves were installed.

Version A (engine 616.916!

Oil pressure relief valve (8 bar gauge pressure), part

No. 100 180 03 15, with 3 control bores.
Version B (engines 616.91 6 and 617.910)

Oil pressure relief valve (8 bar gauge pressure), part

No. 616 180 00 15, with diagonal slot (shark mouth).

Version C (engines 615.9401941, 616 and 61 7)

Oil pressure relief valve ( 5 bar gauge pressure), part

No. 1 15 180 02 15, with axially offset control bores.

Version D (engines 615.91 21913)

Oil pressure relief valve ( 5 bar gauge pressure), part

No. 1 15 180 02 15, with 3 control bores.

Complaints concerning engines 616.916, 61 7.910

On these engines, when engines are cold, oil noises or

a pressure drop may occur (at idle below 2 bar with
cold oil or 1 bar with warm oil). As a remedy, the oil
pressure relief valve of version C may be installed.

Loose or dropped oil pressure relief valves can be

screwed in using sealing compound, part No. 002 989
94 71.
A. Engine 61 5.91 2/91 3

Removal

1 Unscrew closing plug on face.

2 Unscrew oil pressure relief valve (arrow).

lnstallation

3 For installation proceed vice versa. Screw-in closing

plug with new sealing ring.

B. Engine 615.940/941, 616 and 617

Removal

1 Drain engine oil.

2 Remove oil pan lower half.

3 Unscrew oil pressure relief valve on oil pump.

Installation

4 For installation proceed vice versa. Correct oil level

in engine.
20-005 Coolantcircuitandenginecooling

A. Model 1 15.1 and 123.1 (version up t o February 1979)

Coolant circuit

Circuit at coolant temperatures above approx. 9 4 ' ~

1 Waterpump A to radiator
2 Radiator B f r o m radiator
3 Radiator cap, C to water p u m p
code N o . 100 (bypass line)
4 Thermostat D f r o m engine
6 Temperature transmitter E vent line
for telethermometer
12 Regulating valve for
valve heater
13 Heat exchanger
Thermostats

Thermostat begins Up to Starting Starting begin

Engine
to open a t engine No. engine No. of series

The thermostat layout on model 123.1 ( 1 s t version)

differs. On vehicles without air conditioning system,
the thermostat housing with thermostat i s located
horizontally and on vehicles with air ,conditioning
system vertically for reasons of space.

Layout on vehicles without air conditioning

The ID'Sof connections in direction of radiator were

reduced from 35 mm to 29 mm.

When filling, unscrew vent screw (arrows) on thermo-

s t a t housing cover until coolant flows out.

Layout on vehicles with air conditioning

The main valve is closed up to a coolant temperature
of approx. 8 0 ' ~and the bypass disc is fully opened.
The flow ( B ) from radiator is thereby interrupted and
the coolant flows via bypass line (C) directly to water
Pump.

A to radiator
B from radiator
C bypass line
D from cyl~nderhead

A t coolant temperatures of approx. 8 0 ' ~to 9 4 " ~ ,the

main valve as well as the bypass valve are more or less
opened, depending on engine load. The coolant flows
via radiator ( A ) and bypass line ( C ) to water pump.

A to radiator
B from radiator
C by pass line
D from cylinder head

A t coolant temperatures above approx. 9 4 ' ~ , the by-

pass line ( C ) i s closed by the bypass disc. The entire
coolant volume should flow through radiator (refer
to overall diagram). I t is therefore wrong to remove
thermostat for better cooling of engine.

If the thermostat is replaced, make sure during instal-

lation that the punched-on arrow is pointing upwards
or in driving direction toward the rear.
B. Model 123.1 (2nd version starting February 1979)

Coolant circuit

Circuit at coolant temperatures above approx. 9 4 " ~ .

1 Water p u m p A t o rad~ator
2 Rad~ator B f r o m radiator
4 Thermostat C t o water pump (bypass Ilne)
6 Temperature transmitter D f r o m engine
f o r telether m o m e t e r E vent line
1 2 R e g u l a t ~ n gvalve f o r
vehtcle heater
13 H e a t exchanger

Thermostat

The thermostat installed on all engines begins to open

at 8 0 " ~ .
The main valve i s closed up to a coolant temperature
of approx. 8 0 ' ~and the bypass disc is fully opened.
The flow (0) from radiator is thereby interrupted and
the coolant flows via bypass line (C) directly to water
Pump.

A to radiator
B from radiator
C bypass line
D from cylinder head

At coolant temperatures of approx. 8 0 ' ~to 9 4 ' ~ ,

the main valve as well as the bypass valve are more or
less open, depending on engine load. The coolant
flows via radiator ( A ) and bypass line (C)to water
Pump.

A to rad~ator
B from radiator
C bypass line
D from cylinder head

At coolant temperatures above approx. 94Oc, the by-

pass l ~ n e(C) is closed by the bypass disc. The entire
coolant volume should flow through radiator (refer
to overall diagram). I t is therefore wrong to remove
thermostat for better cooling of engine.

Venting of thermostat housing

The thermostat housing is suspended and has an inte-

grated, independent venting system.

The air in the cool~ngsystem can flow to the radiator

and the expansion tank through a bore which bypasses
the thermostat.

a from radiator
b to rad~ator
This venting method has the following advantages:

a) When filling-in the coolant, the coolant circuit will

be independently vented.

b) Better continuous venting of coolant circuit when

engine is operating.

Engine cooling

The spring-loaded cap (code No. 100) on radiator es-

tablishes a gauge pressure of approx. 1 bar (atij) in
the cooling system.

The cooling system is filled ex factory for use through-

out the year with a coolant which comprises approx.
55 % by volume of water and 45 % by volume of anti-
freeze.

The anti-freeze provides protection down to -30'~

and by means of additives in anti-freeze prevents cor-
rosion in cooling system. Since the additives are sub-
ject to ageing, the coolant should be changed every
two yerars.

If no anti-freeze is available and only water is filled in,

be sure to add 1 % of treating compound (anti corro-
sion oil) ( 1 0 cc/i water).

On model 1 15.1 always add 1 % = 10 cc/l of treating

compound for lubricating heater valves, also when
using anti-freeze.

The anti-freeze increases the boiling point, which

amounts to approx. 1 1 8 * for
~ water at 1 bar (atii)
gauge pressure, to approx. 1 2 5 ' ~by the mixture fil-
led-in at the factory.
The red mark on telethermometer begins at 122'~
(since the middle of May 1975, formerly a t 1 1 5 ~ ~ )

This point must be specially observed when only

water and treating agent are filled in. In such a case,
water may be thrown out before the indicator of the
coolant thermometer is at the red mark.

When driving under full load, on mountain roads and

bumper to bumper, or following a fast ride on an ex-
press highway with subsequent traffic congestion, or
when driving in areas with high outside temperatures,
the coolant temperature indicator may rise up to the
red mark if an anti-freeze of at least -30'~ is filled
in, without any ejection of coolant or faulty running
of engine.

When the engine is operated for an extended period

with the vehicle stopped, e.g. vehicle congestion, i t
will be of advantage on vehicles with automatic trans-
mission to move the selctor lever into position ,,N".
This will reduce the heat development in transmission
and thereby additional heating up of coolant by way
of the transmission oil cooler.

When coolant i s lost by leaks in cooling system or by

ejection as a result of overheating, add a pertinently
prepared coolant.

Losses caused by evaporation can be compensated by

adding tap water.
20-010 Draining and filling-in of coolant - Anti-freeze table
-

Tightening torques Nrn (kpd

--

Drain plug radiator model 1 15.1 6-10 (0.6-1

Drain plug radiator model 123.1 1.5-2') (0.15-0.2)

'1 T h i s t o r q u e can b e set b y means o f a washer o r a coin.

Mixing ratio of anti-freeze1) and water2)

Anti-freezelwater in liters
ModeI
115.1

Engi ne

n n rl- I r eere
- 30"~
up to
- 40" c
Total filling capacity in liters 11 10 11

I Refer t o specifications f o r service p r o d u c t s page 325.

) Refer t o specifications f o r service p r o d u c t s page 310.
3 , W i t h water, a d d 1 % = 10 cc/l a n t i -c o r r o s i o n c o m p o u n d , o n m o d e l 11 5.1 also w h e n using anti-freeze (refer t o s p e c i f ~ c a t i o n sf o r
service p r o d u c t s page 31 1 ).

Self-made tool for vehicles with automatic climate control

Coupling (I), part No. 002 545 49 28

approx. 1 rn cable 1.5mm 2 black (b) +
approx. 1 m cable 1.5 mrn2 brown (c) -
1 cable terminal +
1 cable terminal -

a = Fixing groove
Note

A thermostat housing with automatic vent is installed

on model 123.1 starting February 1979 (2nd version).

When filling up on vehicles with automatic climate

control, proceed as described in section ,,B".

Draining

1 Open radiator cap in steps (only below 9 0 " ~ ) .

2 Unscrew drain plug on radiator.

Model 1 1 5.1

Model 123.1

3 Unscrew drain plug on cylinder crankcase.

a) Vehicles without automatic climate control

4 Fill-in coolant up to mark on radiator filler neck.

5 On models 115.1 and 123.1 (1st version), open

vent screw on coolant thermostat housing until cool.
ant flows out.

Model 1 15.1

6 Start engine and run warm. Mount radiator cap.

Model 123.1

b) Vehicles with automatic climate control

4 Slowly fill-in coolant up to mark on radiator filler

neck. Do not mount radiator cap.

5 Start engine and run warm up to approx. 4 0 ' ~ .

6 Pull-off plug of heating water pump (arrow) on

feed line. Connect heating water pump to battery
with self-made tool and push ,,DEF"-button.

7 Run engine warm under intermittent acceleration

until thermostat opens.

Note: Mount radiator cap starting at 6 0 ' ~ .

8 Connect heating water pump again to feed line.

9 Check coolant level (below 9 0 ' ~ )and fill-up to

specified level.
20-01 5 Cleaning the colling system
- - -

1 Completely drain cooling system.

2 Remove thermostat element and set heater lever to

warm.

3 Fill cooling system with a 5 % solution of water

and P 3 Standard (made by Henkel) (50 g P3/1 I water
water).

Attention !
On vehicles with al~~rninurn radiator, a neutral cleaner
such as P 3 Croni (made by Henkel) or Grisiron 7220
(made by Farhwerke Hochst) must be used instead of
the heavily alraline cleaner P 3 Standard.

4 Run engine warm at medirlm speed UP tc approx.

80"~ ( 1 7 6 " ~and
) hold at this temperature for about
5 minutes.

5 Stop engine and permit cooling svstem to cool

down to approx. 5 0 " ~
(122'~).

6 Completely drain ~ o l u t i o n .

7 l mmediately thereafter, fill cooling svstem twice

with fresh water, run warm (approx. 5 mint~tes)and
drain.

B. Decalcification, derusting

Attention !
Prior to decalcification, be sure to de-oil cooling sys-
tem, even if there is no visible oiling-~rp.
1 After second flushing job during de-oiling, fill cool-
ing system with a 10 % (100 gll) solution of water and
citric acid, tartaric acid or oxal ic acid (sold by the
chemical trade), while giving preference to citric acid.

2 Run engine warm at medium speed up to approx.

80"~ ( 1 7 6 " ~and
) hold for approx. 10 minutes at
this temperature.

3 Stop engine and permit to cool down to approx.

50"~ (122"~).

4 Completely drain decalcification solution.

5 Flush cooling system at least three times with fresh

water, while running engine for at least 5 minutes
with each flushing charge.

Badly calcified cooling systems may require a repeti-

tion of the treatment. Always prepare a fresh decal-
cification solution and repeat flushing steps.

6 Install thermostat element with new seal.

7 Fill the cooling system with specified coolant spe-

cification for service products page 310 to 325).

Note: For decalcification and derusting, commercial

products named with the acids nemed above may also
be used.

Chromic acid or products containing chromates are

prohibited by sewage regulations.
20-1 10 Removal and installation of thermostat

Tightening torques Nm (kpm)

Screws for thermostat housing cover 10 (1)

Typ 11 5.1 6-1 0 (0.6-1 )

Drain plug, radiator
Typ 123.1 1.5-2') (0.15-0.2)

' ) This torque can be set by means of a washer or a coin.

Special tools

Tester for cooling system

Radiator cap with hose for

leak test

A. Model 1 15.1 and 123.1 ( 1st version up to February 1979)

Removal

1 Drain coolant.

2 Disconnect hose on thermostat housing cover.

3 Unscrew thermostat housing cover.

4 Remove thermostat with seal out of cover.

Installation

5 When a riew thermostat is installed, place a new

gasket on tnermostat housing.

6 Position thermostat with gasket in cover in such a

manner that tne arrow on therrnostat is pointing up-
wards or toward the rear in installed coridition.

7 Screw-on cover and connect hose.

8 Add coolant (20-010).

9 Pressure- test cool~ngsystem WI th tester.

B. Model 123.1 (2nd version starting

February 1979)

Removal

1 Drain coolant.

2 Disconnect hose on therrnostat housing cover.

3 Unscrew thermostat hous~ngcover.

4 Remove thermostat with gasket out of cover.

5 When a new thermostat is installed, place a new
gasket on thermostat housing.

6 Position thermostat with gasket in cover in such a

manner that the arrow on thermostat i s pointing up-
wards or toward the rear in installed condition.

7 Screw-on cover and connect hose.

8 Add coolant (20-010).

9 Pressure-test cooling system with tester.

20-210 Removal and installation of water pump

Tightening torques Nm (kpm

- - - - -- -

type 11 5.1 6-10 (0.6-1)

Drain plug, radiator
type 123.1 15-2') (a 15-0.2)

Water pump to water pump housing 9 (0.9)

Fan to water pump 25 (2.5)

' ) Thls torque can be set by means of a washer or a c o ~ n .

Special tools

Tester for cooling system

Radiator cap with hose for leak test

for leak test

1 Completely drain coolant (20-010)

2 Unscrew fan.

3 Slacken V-belt of alternator and remove.

Drain plug on cylinder crankcase

4 On vehicles with automatic climate control, remove

York refrigerant compressor with carrier and connect-
ed lines and put aside.
For this purpose, on engine 61 7 in model 123.1, re-
move adaptor between air filter and scoop.
5 Unscrew water pump and remove.

Installation

6 Insert water pumpwith new gasketand screw

down.

7 For further installation proceed vice versa.

8 Tension V-belt of alternator ( 13-340).

9 Pressure-test cooling system with tester.

20-220 Reconditioning of water pump

Self-made tools

Spacing plate
b=2mm

Installation sleeve

Note

On engine 61 7.91 2, from engine end No. 046716 to

061 708 with manual transmission and from 043754
to 058448 with automatic transmission, the water
pump of engines 615, 616 with the smaller bearing dia.
of 36 mm (D) has been installed.

1 Fan h u b 7 O -r i n g
2 Water p u m p shaft 8 Impeller
w i t h compact bearing a 22.8-23.2 mm
3 B e a r ~ n ghousing b 2mm
5 Sliding r i n g seal c Vent bores
6 Counter-ring D Bearing dia.

The water pump of engine 61 7.912 has a bearing dia-

meter of 40 mm. In the event of repairs, install the
water pump used up to now.
On engine 617.912 with 9.5 V-belt profile, the water
pump pulley version A has been replaced by version B
with soldered-in cup (arrow) starting October 1978.
In the event of repairs, install new pulley with part
No. 617 205 01 10.

A 1 st version
B 2nd verslon

On engine 616.912, the water pump pulley with 12.5

V-belt profile is installed since February 1979 on ve-
hicles with manual transmission with a diamter of
176 mm ( C ) and on vehicles with automatic transmis-
sion with a diameter of 148 mm (Dl.

C Manual transmission w ~ t hV-belt 12.5 x 1035

D Automatic transmission w ~ t hV-belt 12.5 x 1000

Water pump engine 61 7

1 Fan h u b 7 O-ring
2 Water pump shaft 8 Impeller
w i t h compact bearing a 22.8- 23.2 m m
3 Bearing hous~ng b 2mm
5 Sl~dingrlngseal c Vent bores
6 Counter-ring

Disassembly

1 Support bearing housing with pertinent tubing and

press-out water pump shaft by means of a mandrel.

2 Knock sliding ring seals from bearing housing.

3 Remove counter-ring from impeller.

Note: Always replace compact bearing and fan hub

following disassembly.

Assembly
-

4 Press-in new compact bearing flush with bearing

housing by means of a tube positioned against outer
race.

Do not press against water pump shaft.

5 Coat mounting bore of sliding ring seal in bearing

housing sliding ring with sealing compound.

Press-in or knock-in sliding ring seal with pressing-in

sleeve.

Attention !
Support only against bearing housing and not against
water pump shaft.

6 Coat O-ring on counter-ring with brake cylinder

paste and push with chamfered side (arrow) into tho-
rougly cleaned impeller.
7 Clean sealing surfaces of counter-ring and sliding
ring seal free of dust by means of a chamois cloth.

8 Degrease both shaft studs and impeller in bore.

9 Press-on impeller flush with shaft while SI

water pump shaft.

10 Heat fan hub on a hot plate to approx. 300'~(an-

nealing color dark - up to light blue).

Place heated fan hub on a recessed base. Hold spacing

plate on water pump shaft, slip water pump shaft on
fan hub and apply a blast of compressed air against
hub. Wait for a few seconds until fan hub is firm and
then cool immediately in water bath.
20-225 Sealing of water pump

Self-made tools

Pressing-off disc f o r impeller

Pressing-in sleeve

Fan hub Sliding ring seal

Water p u m p shaft w ~ t h Counter-ring
compact bearing O-ring
Bearing housing l mpel ler
Disassembly

1 Press-off impeller. For this purpose, place pressing-

off disc between impeller and bearing housing.

2 Apply light hammer blows at several points be-

tween bearing housing and sliding ring seal to cancel
the pre-load and force sliding ring seal out.

3 Force counter-ring out of impeller.

Assembly

4 Slightly coat mounting bore of sliding ring seal in

water pump housing with sealing compound.

Press-in sliding ring seal by means of pressing-in sleeve

or knock out.

Attention !
Support at bearing housing only and not at water
pump shaft.
5 Coat O-ring on counter-ring with brake cylinder
paste and push with chamfered side (arrow) into tho-
roughly cleaned impeller.

6 Clean sealing surfaces of counter-ring and sliding

ring seal free of dust with chamois cloth.

7 Degrease shaft stud and impeller in bore.

8 Press-on impeller flush with shaft while support-

ing water pump shaft.
20-230 Removal and installation of water pump housing

Tightening torques Nm (kpm)

type 1 15.1
Radiator drain plug
type 123.1

Water pump to water pump housing 9 (0.9)

Fan to water pump 25 (2.5)

) This torque can be set by means of a washer or a coin.

Special tools

Tester for cooling system

Radiator cap with hose for

leak test

Socket 27 mm, 112" square

for rotating engine

Removal

1 Completely drain coolant (20- 010).

2 Remove radiator (20-420).

3 Unscrew fan.

4 Slacken V-belt and remove.

Drain plug on cylinder crankcase

5 On engine 61 7, remove pulley and vibration damper.

6 Disconnect heating water return hose on water

pump housing.

7 Disconnect hose between thermostat and water

pump housing.

8 Unscrew vent line from water pump housing (ar-

row).

9 Unscrew water pump housing and remove together

with water pump.

Installation

10 Position water pump housing with new gasket and

screw down.

11 For further installation proceed vice versa to re-

moval.

12 Add coolant (20-010).

13 Pressure-test cooling system with tester.

20-31 0 Viscofan coupling, temperature-controlled (engine 617 )

Operation

The Viscofan coupling is a maintenance-free, hydrau-

lic coupling which operates independent of tempera-
ture as well as infinitely variable.

When the engine is started (cold start), the fan will in-
itially run at higher speed until the oil has flown back
from the working chamber (75) into the reservoir (74)
(approx. 1-3 minutes). The fan coupling will then
switch off. The fan speed in disconnected condition
depends on engine speed, but a fan speed of approx.
2 1 OOImin should not be exceeded.

This condition remains in force as long as the engine

maintains its normal operating temperature.

If the coolant temperature increases as the result of a

higher load or higher outside temperatures, the air
which flows through the radiator and actuates bimetal-
lic s t r i p will become warmer. The bimetallic strip (69)
changes its shape under the increasing heat and opens
at approx. 7 3 ' ~a valve by means of a control pin (68)
and thereby the path of the oil from the reservoir (74)
into the working chamber (75) so that the fan will be
additionally engaged.
Detail on A
During this control operation, the coolant temperature
is between 90 and 9 5 " ~ .

With the clutch engaged, the fan speed in lower speed

range will increase approximately proportional with
the increasing engine speed, but will not exceed 35001
min in upper speed range.

Checking connected temperature

60 Coupling body (secondary member 1

Run engine at 4000-4500lmin. When a coolant tem- 6 1 Pulley (primary member)
perature of 90 to 9 5 ' ~is attained, the fan speed 62 Flange shaft
6 3 Sealing ring
should increase by approx. 1 OOOImin., which can be 64 Needle bearing
clearly noticed accoustically. 6 5 Cooling fins
6 6 Oil scraper
6 7 Compression spring
6 8 Control pin
6 9 Bimetallic strip
Reconditioning 70 Cover with holding clip
71 Intermediate washer
7 2 Feed hole
A defective coupling cannot be repaired with work- 7 3 Valve lever
74 Reservoir
shop equipment, and a new coupling should be instal- 75 Work chamber
led.
Transportation and storage

Temperature-controlled Viscofan couplings should be

transported and stored vertically. For short periods-
e.g. during assembly - the coupling may rest on a
flange, but never on front end.
20-490 Thermostat layout

A. Engines 615, 616 in model 115.1

38 Screw 4 8 Thermostat housing

39 Sealing ring 4 9 Gasket
42 4 combination screws 57 Hose
43 Thermostat housing cover 58 Clamp
44 Gasket 59 Water pump with housing
45 Thermostat
6. Engines 615, 616 in model 115.1 with air conditioning system

38 Screw 46 Screw
39 Sealing ring 47 Spring washer
42 3 combination screws 48 Thermostat housing
43 Thermostat housing cover 49 Gasket
44 Gasket 57 Hose
45 Thermostat 58 Clamp
59 Water pump with housing
C. Engine 617 in model 115.1

38 Screw 46 Screw
39 Gasket 47 Spring washer
42 3 combination screws 48 Thermostat housing cover
43 Thermostat housing cover 49 Gasket
44 Gasket 57 Hose
45 Thermostat 58 Clamp
59 Water pump with housing
D. Engine 617 in model 1 15.1 with air conditioning system
Engines 61 5, 61 6 in model 123.1 (1s t version) with air conditioning system

38 Screw 4 6 Screw
39 Sealing ring 4 7 Spring washer
4 2 4 combination screws 4 8 Thermostat housing
43 Thermostat housing cover 49 Gasket
4 4 Gasket 57 Hose
4 5 Thermostat 58 Clamp
59 Water pump with housing
E. Engines 615, 616, 617 in model 123.1 (1st version)

42 3 combination screws 46 Screw

43 Thermostat housing cover 47 Spring washer
44 Gasket 48 Thermostat housing
45 Thermostat 49 Gasket
57 Hose
58 Clamp
59 Water pump with housing
F. Engines 615, 616, 61 7 in model 123.1 (2nd version)

42 3 combination screws 46 2 screws

43 Thermostat housing cover 47 2 spring washers
44 Gasket 48 Thermostat housing
45 Thermostat 49 Gasket
57 Hose
58 Clamp
59 Water pump with housing