SECTION

LOCOMOTIVE 1
SERVICE MANUAL

FUEL SYSTEM AND ENGINE STARTING

DESCRIPTION fuel tank through the return fuel sight glass mounted on the filter
housing. A restriction inside the return glass causes back
A pictorial diagram of the fuel oil system is shown in Fig. 1-l. pressure, thus maintaining a positive supply of fuel for the
Fuel is drawn from the storage tank through a suction fuel injectors.
strainer by the motor driven gear type fuel pump.
The fuel pump delivers more fuel to the engine than is burned in
From the pump the fuel is forced through a double element fuel the cylinders. The excess fuel circulated is used for cooling and
filter mounted on the engine. After passing through the filter, lubricating the fine working parts of the injectors.
the fuel flows through manifolds that extend along both banks
of the engine. A primary fuel filter and a 207 kPa (30 psi) fuel filter bypass
valve can be provided upon special request of the customer. If
These manifolds supply fuel to the injectors. The excess fuel not equipped, the 207 kPa (30 psi) bypass valve is connected across
used by the injectors returns to the the primary fuel filter so that fuel will be supplied to the engine
in case the primary fuel filter becomes clogged
.

Fig.1-1 - Fuel Oil System, Pictorial Diagram

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FUEL SIGHT GLASSES EMERGENCY FUEL CUTOFF SWITCHES

Two sight glasses, Fig. 1-2, are located on the engine mounted In the event of an emergency, the fuel supply to the engine can
filter housing to give visual indication of fuel system condition. be stopped by pressing on any one of the three emergency fuel
cutoff switches. Two switches, one on either side of the
For proper engine operation the return fuel sight glass (the glass locomotive, are located on the underframe in the vicinity of the
nearer the engine) should be full, clear, and free of bubbles. The fuel filter, and the third switch is located on the engine control
fuel flowing through this glass is the excess not required by the panel. The switches are connected in series with the fuel pump
engine. Upon leaving the glass it returns to the fuel tank for control relay FPCR. Pressing in on any of the switch buttons,
recirculation. momentarily, will de-energize the FPCR, stop the fuel pump,
and shut down the engine. The buttons are spring loaded and do
At the time of engine start the sight glass will be empty. When not need to be reset. See the fuel pump circuit drawing at the
the fuel system is primed, turbulent flow will occur and when end of this section.
the fuel in the glass flows clear and free of bubbles the engine
may be cranked. MAINTENANCE
The engine mounted filter is also equipped with a bypass relief
valve and sight glass. This sight glass, farther from the engine, FUEL STORAGE FACILITIES
is normally empty. When more than a trickle of fuel is seen in
the bypass sight glass, it indicates that the relief valve is open. Effective wayside fuel filtration is necessary to ensure
Fuel will pass through the bypass sight glass and relief valve to cleanliness, quality, and uniformity of the fuels supplied to the
bypass the engine and return to the fuel tank when the filter engine fuel tanks. This is especially true since 1974, due to a
elements become clogged. This general decrease in fuel cleanliness resulting from more
condition may become serious and cause the engine to shut frequent fuel turnover (shortened storage tank settling time), and
down from lack of fuel. reduced fuel inventories (which can result in increased agitation
of tank bottoms during filling).

Fuel contaminants can be classified into two categories; soft or

deformable, and hard. Soft contaminants include micro-
organisms (such as bacteria and algae), waxes, and water. Hard
contaminants include rust, scale, cracking catalyst fines, dirt,
and wear metals.

Soft contaminants such as waxes generally are kept in

suspension and do not normally cause trouble. However, both
water and micro-organisms are detrimental to fuel system
components. The presence of slime on fuel filters indicates that
bacteria and fungi are present in troublesome quantities. The
effects of water in fuel are well known, and it is recognized that
water must be removed or kept at the lowest possible level.

Electro-Motive strongly recommends the utilization of wayside

fuel filtration facilities that will efficiently remove water and
contaminants 2 micron size and larger, and provide fuel that
meets the cleanliness specifications given in the applicable
Maintenance Instruction.

Fig.1-2 - Engine Mounted Fuel Filters With Sight Glasses

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DRAINING CONDENSATE FROM THE FUEL

TANK
Condensate should be drained from the locomotive fuel tank at
the intervals stipulated in the Scheduled Maintenance Program,
or more frequently if conditions warrant. During draining, the
locomotive should be placed on an incline with the drain end of
the tank facing downhill to facilitate Condensate drainage. A
ball valve drain, Fig. 1-l, is provided for this purpose. To drain,
simply remove the pipe plug and position flow indicator to
"open."

FILLING THE FUEL TANK

The fuel tank can be filled from either side of the locomotive. A
short sight level gauge is located next to each fuel filter. This
gauge indicates the fuel level from the top of the tank to about
114 mm (4-1/ 2") below the top and should be observed while
filling the tank to prevent overfilling. DO NOT HANDLE
FUEL OIL NEAR AN OPEN FLAME. The basic filler cap
assembly, Fig. 1-3, is equipped with a screen strainer, and
should be periodically inspected. Also check the condition of
the filler cap gasket and replace with a new one if necessary.
See Service Data.

Fig.1-4- Fuel Suction Strainer, Exploded View

Fig.1-3 - Fuel Filler Assembly 3. Withdraw the mesh strainer element, discard the oil and
sediment held in the strainer shell.
FUEL SUCTION STRAINER
4. Clean the mesh element in a container of clean fuel oil. A
brush may be used and a round wooden dowel employed
The fuel suction strainer, Fig. 1-4, should be cleaned and
to spread the pleats and determine the degree of
inspected at the intervals stated in the Scheduled Maintenance
cleanliness, but no special tools are necessary.
Program or at shorter intervals if operating conditions warrant.
CAUTION
CLEANING PROCEDURE Chlorinated hydrocarbon solvents and
temperatures above 82° C (180° F) will damage
1. Stop the diesel engine, and place the fuel pump circuit the epoxy material bonding the strainer element to
breaker in the OFF position. the end caps.
2. Remove the bolts holding the strainer shell to the strainer 5. Clean the shell with fuel oil and wipe clean. Note that the
cover, and remove the shell and strainer from the cover. spring in the bottom is spot welded to the shell.
To prevent loss, thread the bolts with washers into the
strainer shell threaded openings. 6. Inspect the housing-to-cover "O" ring, and replace it with
a new ring if necessary.

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7. Place the cleaned strainer element in the shell and reapply

the shell to the strainer cover. Tighten firmly into place 6. Inspect the filter housing cover gasket and replace with a
after making certain the "O" ring is properly seated new gasket if necessary. Replace the housing cover and
firmly tighten the retaining bolts.
PRIMARY FUEL FILTER
(Special Order) 7. Retighten the pipe plug at the base of the filter housing.

The primary fuel filter element, Fig. I-5, should be changed at 8. Operate the fuel prime switch until fuel runs free and
the intervals stated in the Scheduled Maintenance Program or at clear of bubbles in the return fuel sight glass. Check for
shorter intervals it operating conditions warrant. leakage at the drain plug and the housing cover.

PRIMARY FUEL FILTER BYPASS VALVE

AND GAUGE (Special Order)
This gauge, Fig. I-6, indicates the condition of the primary fuel
filter. Increased pressure differential across the primary fuel
filter will be indicated by a greater reading on the gauge.
Normally, with a new primary filter, the gauge should read in
the green zone.

Fig.1-5 - Primary Fuel Filter And Housing

CLEANING PROCEDURE
1. Stop the diesel engine, place isolation switch in
ISOLATE position.
Fig. 1-6 - Primary Fuel Filter Bypass Valve And Gauge
2. Place a container which will hold approximately 19 litres
(5 gallons) under the filter housing to catch fuel drainage, As the filler element becomes plugged, the indicator will read
and remove drain plug. higher until it reaches the red CHANGE FILTER one at
approximately 207 kPa (30 psi) pressure differential. At this
NOTE point, the bypass valve will begin to open, allowing the fuel oil
to bypass the primary fuel filter. Renew primary fuel filter
If the pipe plug or the filter cover are opened shortly after element when the indicator reaches the CHANGE FILTER
engine shutdown, pressure retained in the system will cause fuel zone.
to spurt out o1 the opening.

3. Loosen the filter cover plate retaining nuts, then twist the
cover and remove it. Withdraw and discard the filter
clement.

4. Place the fuel prime switch in FUEL PRIME position to

introduce a flow of fuel and wash out any sediment that
may be held at the base of the filter housing.

5. Insert a new filter into the housing being careful not to

damage the lower seal on the filter element.
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ENGINE MOUNTED FUEL FILTERS The fuel pump and motor need no routine maintenance if
operation is satisfactory. However, the motor and pump should
The engine mounted fuel filters should be changed at the be reconditioned in accordance with EMD Maintenance
intervals stipulated in the Scheduled Maintenance Program, or Instructions listed on the Service Data page. Maintenance
whenever fuel appears in the bypass sight glass. The filter should be performed at the intervals stipulated in the Scheduled
assembly should be maintained in accordance with the Maintenance Program.
instructions in the Engine Maintenance Manual.
CAUTION
Refer to the following procedure while changing filter elements. Use care during washing of the engineroom to protect the fuel
pump motor from water. Water in the motor can cause an
1. Shut engine down. electrical ground.

2. Unscrew and discard the elements. Use a strap wrench if FUEL PUMP CIRCUIT (MU)
necessary.
When locomotive control circuits are established, and the
3. Clean the filter and sight glass assemblies. control and fuel pump switch on the control stand is closed, the
fuel pump relay FPR, Fig. 1-8, is energized. This establishes a
4. Apply a film of oil to the element gaskets. circuit that provides the operator with the means of shutting off
the fuel pump from a switch on the control stand. However,
5. Apply the elements to the filter body. Hand tighten until before the engine is running, the fuel pump relay performs no
the gasket contacts the filter body, then tighten one-half function.
turn.
With the control circuits established, the No. 1 contact of the
6. Check for leaks after the engine is started. fuel prime/engine start switch is energized. Power is supplied to
the fuel pump contactor coil when the switch is held in the
FUEL PUMP AND MOTOR FUEL PRIME position. The contacts of the fuel pump contactor
close to supply power to the fuel pump motor.
The motor driven fuel pump, Fig. 1-7, is mounted on the
equipment rack. It is an "internal" gear pump driven by battery After the system is primed and fuel flows free and clear in the
power during system priming and by power from the auxiliary return fuel sight glass, the fuel prime/ engine start switch FP/ES
generator during operation. is rotated to the START position. The fuel pump contactor is
held picked up, and the 9-10 contacts of FP/ES switch close to
pick up the fuel pump control relay FPCR. Other contacts of
FP/ES are used in the engine starting circuit.

The battery continues to power the fuel pump motor until engine
speed comes up sufficiently to cause auxiliary generator output
voltage to exceed battery voltage. If the FP/ES switch is
released after the engine fires, but before engine speed and
auxiliary generator voltage are up, the fuel pump contactor may
drop out. However, fuel in the system will allow the engine to
come up to speed, and when auxiliary generator voltage is
sufficient the fuel pump contactor will again pick up.

Fig.1-7 - Fuel Pump Cross Section

Fuel is drawn into the inlet portion to fill a space created by the
gear teeth coming out of mesh. The fuel is then trapped in the
space between the gear teeth and carried to the outlet side of the
pump. There the gears mesh, forcing the fuel from between the
gear teeth and through the outlet.

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When the locomotive controls are properly set up for engine

starting, the isolation switch (IS) is in START position and the
fuel pump relay FPR is energized. When the Fuel Prime/ Engine
Start FP/ES switch is held in the FUEL PRIME position, Fig. 1-
8, battery power is applied to the fuel pump contactor coil FPC
through FP/ES contacts 1-2. Pickup of FPC provides a feed to
the fuel pump motor. The fuel pump provides fuel to the engine
injectors and is returned to the fuel tank by way of the return
fuel sight glass on the engine mounted fuel
filter.

After the system is primed, hold the FP/ES switch to ENGINE

START. This energizes the generator (engine) start contactor
GS, Fig. 1-9, and the fuel pump contactor FPCR, Fig. 1-8.
Pickup of GS provides cranking power to the main generator.
Pickup of FPCR sets up the fuel pump circuit so that the fuel
pump is connected to the auxiliary generator when FP/ ES is
released. Pickup of FPCR also provides a holding circuit to
FPCR. FPCR remains energized until the feed is interrupted by
opening the EFCO/STOP, EFCO1, or EFC02 switch. Opening
the feed to FPCR provides a feed to the governor DV solenoid
which results in immediate engine shutdown by withdrawing the
injector racks. Opening the Control and Fuel Pump switch
removes power from the fuel pump motor, but the engine will
continue to run until the fuel in the system is used.

After the engine has started, and FP/ ES is released, GS drops

out to remove cranking power from the main generator. Power
is provided from the auxiliary generator to the fuel pump
contactor through FPR, FPCR, and FP/ES contacts 5-6.

ENGINE STARTING PROCEDURE

CAUTION
Before attempting to start a new engine, an engine that has been
overhauled, or an engine that has been shut down for more than
Fig.1-8 - Fuel Pump Circuit 48 hours, perform PRELUBRICATION OF ENGINE procedure
contained in Section 2. If engine temperature is near 0° C (30°
The fuel pump motor will stop if either the fuel pump relay FPR F) the engine should be preheated prior to starting.
or the fuel pump control relay FPCR opens to drop out the fuel
pump contactor FPC. However, dropout of FPR and FPC will 1. Check oil level of engine, governor, and air compressor,
not immediately stop the engine. Dropout of the fuel pump and add oil if required. Check engine oil level in strainer
control relay FPCR is required for immediate withdrawal of housing and, if required, add oil to strainer housing until
injector racks and engine shutdown. it overflows into the oil pan. Make certain that the
strainer element is securely seated.
ENGINE STARTING CIRCUIT 2. Check engine coolant level.
The D32 generator is used as a motor to crank the engine during
engine start. This eliminates the necessity for separate starting
motors.

The D32 generator is equipped with a shunt field, a separately

excited field (battery field), and a starting field. During engine
start the starting field is used and the battery field is
disconnected. However, during power operation the battery field
is used and the starting field is disconnected.

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Fig.1-9 - Starting Circuit Of GP15-1, Simplified Schematic Diagram

3. Open cylinder test valves and bar over the engine at 8. Place generator field and engine run switches in the
least one revolution. Observe for leakage from test OFF (down) position.
valves. Close the test valves.
9. Place the isolation switch in the START position.
NOTE
10. At the equipment rack in the engineroom, place the
It is good practice and highly recommended that the Fuel Prime/Engine Start Switch in the PRIME
engine be barred over one complete revolution with the position until fuel flows in the return fuel sight glass
cylinder test valves open before starting. If any fluid clear and free of bubbles. On units so equipped, if
discharge is observed from any cylinder, find the cause the automatic water drain system was disabled prior
and make the necessary repairs. This practice should apply to engine start, placing the switch in PRIME
particularly to engines that are approaching a scheduled position will turn off the WATER DRAIN
overhaul after several years of service or have had a DISABLED light.
history of water or fuel leaks.
11. Check that the starting fuse is in good condition and
4. Remove the starting fuse. Check that all other fuses of the proper rating. Install starting fuse, Fig. 1-10.
are installed, are in good condition, and are of the
proper rating. CAUTION

5. Verify that the main battery switch is closed, and Do not crank engine for more than 20 seconds or "inch"
that the ground relay switch is closed. engine with starter.

6. Place the local control and the control circuit If engine is equipped with purge control system, do not
breakers in the ON (up) position. push injector rack control lever (layshaft) until engine has
cranked for six seconds.
7. Place the control and fuel pump switch in the ON
(up) position.

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Fig.1-10 - Starting Fuse - 400 Amperes

12. Position the injector control lever (layshaft lever) at 14. Check that the low water detector is not tripped. If
about one-third rack (approximately 1.6 on the the detector is tripped, wait for one-half minute after
scale), then move the Fuel Prime/ Engine Start engine start, then press the reset button and hold for
switch to the START position. Hold the switch in five seconds to reset. If the detector trips again,
the START position until the engine fires and speed verify engine oil pressure, then slowly position the
increases. injector control lever to increase engine speed
momentarily before resetting the button.
13. Release the injector control lever when the engine
comes up to idle speed. Do not advance lever to 15. Check that cooling water level is satisfactory, that
increase engine speed until oil pressure is lube oil pressure is satisfactory, and that governor
confirmed. oil level is satisfactory.

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SERVICE DATA

FUEL SYSTEM AND ENGINE STARTING

REFERENCES

Diesel Fuel Recommendations - All EMD And Former CDED Diesel Engines ............ M.I. 1750
Fuel And Soak Back Pumps ......................................................... M.I. 4110
Fractional Horsepower Motors ....................................................... M.I. 4101

ROUTINE MAINTENANCE PARTS AND EQUIPMENT

FILTERS

Part No.

Primary Fuel Filter...................................................... 8379120, 9502100

Pleated Paper Element........................................................ 8345482
Cover Gasket.................................................................... 8358905
Engine Mounted Filter Assembly ................................................... 8479355
Filter Element............................................................... 8423132
Suction Strainer.................................................................. 8341983
Wire Mesh Element .......................................................... 8344103
"O" Ring, Housing-To-Cover.................................................. 8343161
Pressure Differential Gauge With Bypass Valve....................................... 9323489

FUEL PUMP

Fuel Pump Flange Gasket......................................................... 8426937

SPECIFICATIONS

Fuel Tank Capacity - Basic .............................................. 9 085 Litres (2400 Gal.)

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