Service Information

Document Title: Function Group: Information Type: Date:

Steering, description 600 Service Information 2014/4/28
Profile:
WLO, L90E [GB]

Steering, description

Figure 1
Steering system (principle diagram)

1. Steering valve
2. Hydraulic tank
3. Steering cylinder (2 pcs.)
4. Accumulator (2 pcs.)
5. Central valve
6. Hydraulic pump

The machine is equipped with hydrostatic load-sensing (LS) articulated steering, consisting of hydraulic pump P2, steering
valve, two accumulators and two steer cylinders.
Pump 2 (P2) is a variable axial piston pump located on the transmission's power take-off. P2 supplies oil to the central block.
The function of the central block is to distribute oil and pressure to brakes, steering (prioritized), servo and working
hydraulics.
Description central block, see Section 9.
The function of the accumulators is to give a slow pressure build-up, which results in smoother steering.
Steering valve
The steering valve is a non-reaction type with closed centre. The steering valve has a load sensing connection (LS), from
which a steering pressure is obtained to the central block's LSS-connection. From the central block's LSP-connection, the
steering pressure passes to the flow compensator on P2.
Figure 2
Steering valve

A. T-shaped groove (inner slide)

B. Hole (outer slide)
C. Punch marks, should line up when mounting
 Service Information

Document Title: Function Group: Information Type: Date:

Hydraulic pump, 645 Service Information 2014/4/28
description
Profile:
WLO, L90E [GB]

Hydraulic pump, description

The pump is a nine cylinder axial piston pump with variable flow.
The drive shaft (9) rotates, and the cylinder block (6), pistons (7) and the swash plate (8) rotate with it. The stroke of the
pistons will then be dependent on the angle of the regulating plate (10). The angle is determined by the difference between
the pressure from the hydraulic pump's control piston and the spring force acting on the regulating plate (10).
When the piston is in its innermost position, it passes (during the movement out), a concentric groove (4) in the distribution
plate (5). Oil is sucked (or more correctly, forced by atmospheric pressure) from the inlet port (3) via the inlet groove (4) into
the cylinder.
When the piston has passed its outermost position and is on its way into the cylinder, oil is pressed out through the outlet
groove (2) and on to the outlet port (1).

Figure 1
Hydraulic pump

1. Outlet port
2. Outlet groove in distribution plate
3. Inlet port
4. Inlet groove in distribution plate
5. Distribution plate
6. Cylinder block
7. Piston
8. Swash plate
9. Drive shaft
10. Regulating plate

Pressure/flow compensator, description

The function of the flow compensator (14) is to always control the pump via the control piston (11), so that it delivers an oil
flow with a pressure-drop in the system that corresponds to a fixed pressure difference between the pump's outlet and the
load-sensing port on the regulator.
The function of the pressure compensator (13) is to control the pump via the control piston (11) so that the max. pressure
for working hydraulics is limited.
Figure 2
Hydraulic pump

5 Distribution plate
6.7 Pump unit (with cylinder block and piston)
9 Drive shaft
10 Regulating plate
11 Control piston
12 Housing
13 Pressure compensator
14 Flow compensator
15 Bearing
16 Bearing

Figure 3
Hydraulic pump

1. Hydraulic pump
2. Inlet
3. Pressure compensator (main pressure)
4. Flow compensator
5. Outlet
 Service Information

Document Title: Function Group: Information Type: Date:

Steering cylinder, sectional 645 Service Information 2014/4/28
view
Profile:
WLO, L90E [GB]

Steering cylinder, sectional view

Figure 1
Steering cylinder, sectional view
 Service Information

Document Title: Function Group: Information Type: Date:

Steering valve, description 645 Service Information 2014/4/28
Profile:
WLO, L90E [GB]

Steering valve, description

Figure 1
Steering valve

The steering valve is of the "non-reaction" type with closed centre. The steering valve has a load-sensing port (LS), from
which a steering pressure goes to the central block's LSS-connection. From the central block's LS-connection the steering
pressure goes to the flow compensator on P2 (as well as P1 if the machine is not equipped with LS-separation).

Figure 2

A. T-shaped grooves (inner spool)

B. Holes (outer spool)
C. Punch marks, should line up when assembling

Function
When the steering wheel is kept still, the steering valve is in neutral, which means closed centre. The pump is in the non-
angled position and only supplies a stand-by pressure.
Figure 3
Steering valve, neutral position

Turning the steering wheel in either direction causes the inner and outer spools to turn relative to each other. When this
turning (displacement) has amounted to 1.5° the ducts to the metering unit and the LS-port begin to open. The pressure
from the steering pump is conducted directly to the load-sensing port, thus increasing the angle of the pump causing it to
supply a flow. Via the metering unit oil is supplied to the steering cylinders in proportion to the movement of the steering
wheel. When the steering wheel is released the inner and outer spools spring back to the closed position and the pump only
supplies stand-by pressure.
Figure 4
Steering, activation
Figure 5

Steering valve

1 Seal 15 O-ring
2 Valve housing 16 Distribution plate
3 O-ring/back-up ring 17 O-ring
4 Axial disc 18 Distribution plate
5 Needle bearing 19 Rotor
6 Bearing race 20 Rotor ring
7 Ring (carrier) 21 Cap
8 Inner valve spool 22 Washer
9 Outer valve spool 23 Bolt with guide pin
10 Cross pin 24 Bolt (6 pcs)
11 Leaf springs (4 pcs) 25 Type plate
12 Rotor shaft 26 Blind rivet
13 Ball (non-return valve) 27 LS-connection (load-sensing connection)
14 Bushing

No. 19 and 20 = metering unit

 Service Information

Document Title: Function Group: Information Type: Date:

Steer cylinder, left, 645 Service Information 2014/4/28
changing
Profile:
WLO, L90E [GB]

Steer cylinder, left, changing

Op nbr 64506

9993714 Puller bolt

9993722 Support
11666044 Jack
11666041 Pump
699901 Drift handle
699950 Drift plate
699970 Drift plate

Removing

1. Park the machine in the service position according to 191 Safety rules when servicing

2. Remove the left rear mudguard and side plate by the hydraulic oil tank.

Figure 1

3. Remove the mat and floor plates in the cab.

4. Loosen the tensioning straps and the pin's two lock bolts and connector SE601.
 Figure 2

1. Lock bolt
2. Tensioning strap

5. Remove the grease nipple.

6. Screw in the puller bolt under the rear pin and press it out.

Figure 3

1. 9993714
2. 11666044
3. 11666041

7. Remove the steer cylinder's hydraulic hoses. Plug hoses and cylinder.

8. Remove the front pin's lock ring (1), lock bolt and grease nipple.
 Figure 4
Front steer cylinder pin's lock ring

9. Pull out the front pin and lift away the cylinder. Cylinder weight: approx. 25 kg (55 lb)

Figure 5

1. 11666041
2. 11666044
3. 9993722
4. 9993714

Mounting, rear cylinder pin

10. Clean and inspect the parts for any damage.

WARNING
Risk of crushing injuries

11. Fit the steer cylinder with both rubber gaiters, push in the cylinder carefully.

12. Line up the rubber gaiters.

13. Screw in the guide bolts, 2 pcs. (M8x180mm) in the threaded holes.

14. Cool the steer cylinder pin to -20° C or colder.

15. Fit the steer cylinder pin (2) in its position so that the guide bolts (1) are guided in the two holes for the lock bolts.

Figure 6

16. Screw in the puller bolt and place the jack under the pin.

Figure 7

1. 11666041
2. 11666044
3. 9993714

17. Check that seals and steer cylinder are parallel with the guide pin hole. Screw in the pin completely.

18. Fit the pin's two lock bolts, tensioning straps and connector SE601.
 Figure 8

1. Lock bolt
2. Tensioning strap

19. Fit the grease nipple.

Mounting, front cylinder pin

20. Screw in a guide bolt (1) (M8x180mm) in the fork on the steer cylinder.

Figure 9

21. Cool the steer cylinder pin to -20° C or colder.

22. Align the gaiters and make sure that the pin can pass freely when it's pressed down.

23. Place the cooled pin in the hole and drive it down completely with drift and hammer.

Figure 10

1. Hammer
2. 699901 Drift handle
3. 699950 Drift plate
4. 699970 Drift plate

24. Fit the lock bolt, grease nipple and the steer cylinder pin's lock ring (1).
 Figure 11
Front steer cylinder pin's lock ring

25. Fit the steer cylinder's hydraulic hoses.

26. Fit the mat and floor plates in the cab.

27. Grease the steering cylinder pins. (Also for machines with central lubrication)

28. Restore the machine.

29. Bleed the hydraulic system by carefully alternating between steering right and left. Slowly increase the steering
angle and finally steer to lock in both directions a few times.

30. Test-run the machine and check for correct steering function. Check for any leaks.

31. Fit the side plate by the hydraulic oil tank and the left rear mudguard.
 Service Information

Document Title: Function Group: Information Type: Date:

Steering pressure, checking 645 Service Information 2014/4/28
and adjusting
Profile:
WLO, L90E [GB]

Steering pressure, checking and adjusting

Op nbr 64528

11 666 020 Pressure gauge 0–25 MPa (0–4000 psi)

11 666 037 Hose

WARNING
Do not remain under the machine when the engine is running.

Checking

1. Secure the frame joint with the frame joint lock. Chock the wheels (in front and behind).

Figure 1

2. Connect the pressure gauge to the pressure check connection on the steering valve.
 Figure 2

1. 11 666 020, 11 666 037

3. Start the engine and run at low idle speed. Make sure that the system is at normal operating temperature.

4. Steer towards the frame joint lock's end position and check the steering pressure.
Steering pressure: 21 ±0.35 MPa (3046 ±51 psi)
NOTE!
In neutral position, the pressure gauge normally displays approximately 2.5 MPa (363 psi), which is the priority
valve's opening pressure in the central block.

5. Stop the engine.

Adjusting

6. Adjust the steering pressure on the central block.

Steering pressure: 21 ±0.35 MPa (3046 ±51 psi)

Figure 3

1. Adjusting screw for steering pressure

7. Restore the machine.

 Service Information

Document Title: Function Group: Information Type: Date:

Stand-by pressure (P2), 645 Service Information 2014/4/28
checking and adjusting
Profile:
WLO, L90E [GB]

Stand-by pressure (P2), checking and adjusting

Op nbr 91303

11666019 Pressure gauge

11666037 Hose

Part no. 935756 Plug

The engine, hydraulic transmission and hydraulic system must have reached normal working temperature for checking.

Stand-by pressure, checking

1. Connect the pressure gauge to the pressure check connection on the central block.

Figure 1

1. Pressure check connection

2. Start the engine, run it at low idle speed and read off the stand-by pressure.
Stand-by pressure:2.4–3.5 MPa (24–35 bar) (348–508 psi)

NOTICE
None of the hydraulic functions must be actuated.

Stand-by pressure, adjusting

3. Turn off the engine.

NOTE!
To access the flow compensator on P2, the cab floor's rear plate must be removed.

4. Remove the mat from the cab.

5. Remove the rear plate in the cab floor.

6. Adjust on the pump's flow compensator until correct stand-by pressure is obtained.
 Figure 2

1. Flow compensator
2. Pressure compensator

If adjusting the stand-by pressure doesn't help, check the pressure again, with disconnected LS-line, and adjust
again.

Stand-by pressure, checking (LS-line removed)

7. Connect the pressure gauge to the pressure check connection on the central block.

Figure 3

1. Pressure check connection

8. Disconnect the LS-line that runs from the central block's LSP port. (Carried out so that LS-pressure from the
steering valve and control valve does not affect checking).
 Figure 4

9. The LS-line does not require plugging. Place a container beneath the LS-line to collect any oil that drains.

10. Plug the connection in the central block with the plug.
Part no. 935756.

11. Start the engine, run it at low idle speed and read off the stand-by pressure.
Stand-by pressure:2.2–2.8 MPa (22–28 bar) (319–406 psi)

NOTICE
None of the hydraulic functions must be actuated.

12. Restore the machine to operating condition.

If no higher stand-by pressure is obtained with the LS-line connected, the LS-line may be clogged.
 Service Information

Document Title: Function Group: Information Type: Date:

Steering valve, replacing 645 Service Information 2014/4/28
Profile:
WLO, L90E [GB]

Steering valve, replacing

Op nbr 645-082

14360000 Vacuum pump / 24V

NOTICE
Plug all pipes, hoses and connections when removing.

Removing

1. Place the machine in service position.

2. Connect a vacuum pump to the hydraulic tank. See

911 Hydraulic oil tank, vacuum-pumping, connecting and disconnecting pump

3. Mark up and disconnect all hydraulic hoses from the valve. Fit protective plugs.

4. Fold aside the front floor mat and expose the steering column's lower end.

5. Support the steering valve with a wooden board and wedge.

Remove the attaching bolts and lift away the valve. Weight: approx. 15 kg (33 lb)

Figure 1
 1. Attaching bolts (4 pcs.)

Installing

6. Fit the attaching bolts and the valve.

7. Remove the protective plugs. Connect all marked hydraulic hoses to the valve. Replace damaged O-rings.

Figure 2
Steering valve

8. Fold the front floor mat back into place.

9. Disconnect the frame joint lock.

10. Bleed the hydraulic system by carefully alternating between steering right and left. Slowly increase the steering
angle and finally steer to lock in both directions a few times.

11. Test-run the machine and check for correct steering function. Check for any leaks.

12.
 Service Information

Document Title: Function Group: Information Type: Date:

Steering valve, 645 Service Information 2014/4/28
reconditioning (removed)
Profile:
WLO, L90E [GB]

Steering valve, reconditioning (removed)

Op nbr 64581

6999 007 Handle

6999 025 Plate
6999 034 Plate

Dismantling

1. Mark the steering valve's parts in relation to each other to facilitate assembling.
Secure the steering valve in a vice. Use soft jaws.
Remove the cap.

Figure 1

2. Remove the rotor kit, rotor shaft and distribution plates.

Remove the O-ring.
 Figure 2
Removing rotor kit

3. Remove the lock pin.

Remove the steering valve from the vice and remove the ball.

Figure 3
Removing ball

4. Remove the inner and outer slides.

NOTE!
Do not pull on the outer slide. Risk of separating the parts which means that the return springs will lock the inner
slide in the housing.
 Figure 4
Removing inner and outer slide

5. Remove the thrust plate, needle bearing, bearing race and the ring.

Figure 5
Removing needle bearing and ring

6. Remove the inner and outer seals.

7. Carefully press the inner slide out from the outer slide.
Remove the leaf springs.
Clean and inspect for damage and wear.
Replace worn or damaged parts.
Replace all seals and washers.
Remove any burrs with a fine-grain whetstone.
Lapping paste must not be used.
Lube all parts with hydraulic oil before assembling.
Assembling

8. Fit the outer seal ring.

Secure the valve housing in a vice. Use soft jaws.

Figure 6
Installing seal ring

1. 6999 007
2. 6999 025
3. 6999 034

9. Place the assembled seal on the drift plate and press the seal into the housing.

Figure 7
Installing seal ring

1. 6999 007
2. 6999 025
3. 6999 034

10. Assemble the inner and outer slides so that the grooves for the leaf springs coincide and the T-shaped groove (A)
in the inner slide lines up exactly with the small holes (B) in the outer slide. Check that the punch marks on top of
the slides coincide.
 Figure 8

A. T-shaped groove (inner slide)

B. Hole (outer slide)
C. Punch marks

11. Fit the leaf springs. Make sure that they're fitted correctly.

Figure 9
Fitting leaf springs

12. Fit the thrust plate, needle bearing, bearing race and the ring on the inner and outer slide.
NOTE!
Fit the bearing race with the bevel facing the inner slide. Fit the lock pin on the inner and outer slide.

Figure 10
Fitting thrust plate, needle bearing, bearing race and ring

1. Ring
2. Bearing race
3. Needle bearing
4. Thrust plate

13. Fit the inner and outer slide in the valve housing. Rotate the inner and outer slides so that its drive pin stands 90° in
relation to surface A.

NOTICE
If the inner and outer slides have the incorrect position, the steering valve can function as a motor and the
 machine will self-steer.

Figure 11
Inner and outer slides and drive pin's placement in valve housing

14. Fit the O-ring. Fit the distribution plates so that the channel holes line up with the corresponding holes in the valve
housing.

Figure 12
Distribution plate on valve housing

15. Fit the rotor shaft. Fit the O-ring and the rotor kit so that two of the rotor's gear teeth are parallel with the surface
“A”.

Figure 13
Rotor kit's position in relation to valve housing

16. Fit the cap and bolts.

Fit the ball through pressure connection (P) and then fit the bolt with the lock pin. Wiggle the valve and listen if the
ball can move freely.
Tighten the bolts crosswise.
Tightening torque: 30 - 35 Nm (22 -26 lbf ft)

Figure 14
Ball's position in valve housing
 Service Information

Document Title: Function Group: Information Type: Date:

Description 647 Service Information 2014/4/28
Profile:
WLO, L90E [GB]

Description
The secondary steering is equipment that enables the operator to maintain steering capacity if the primary steering pump
fails. The operator receives information if there's a system malfunction for monitoring the secondary steering system, which
may endanger personnel, machine and property in case of continued operation. Alarm, control as well as logic diagnostics
shall only be performed if the equipment is installed on the machine. See wiring diagram 16.
The system includes an electrically driven hydraulic pump MO601 that is controlled by the V-ECU via RE601.
I-ECU receives its signals from test switches SW601, two sensors (monitors), SE601 and SE602, and the machine's travel
speed sensor SE403.
Differential pressure sensor SE601 senses the difference between the main pressure and LS-pressure.
Pressure monitor SE602 senses the main pressure.

Figure 1
Wiring diagram 16

Before engine start

If test switch SW601 or pressure monitor SE602 is connected, the ECU considers the equipment to be installed.
Figure 2
SW601, located on right instrument panel

V-ECU checks the sensor circuits.

Logic diagnostics:
Engine off and secondary steering pump not active and circuit open for more than 1 sec. With engine off and start key in
operating position, the following takes place in case of any open sensor circuits:

 Amber central warning flashes.

 Error is shown on information display.

ERROR
Monitoring
Steering System
Oil Pressure

V-ECU checks relay RE601.

Logic diagnostics:
Relay check; Error message indicates short-circuit or open circuit. Winding resistance at 20 °C (68 °F), 290–320 ohm. With
engine off and start key in operating position, the following takes place in case of open circuit in relay.

 Amber central warning flashes.

 Error is shown on information display.

ERROR
Secondary
Secondary steering

While operating
In case of primary steering pressure loss, the differential pressure monitor SE601 and primary steering pressure monitor
SE602 will close the switch. This means that the secondary steering pump starts if the speed is above 3 km/h (2 mph). In this
case, the pump will run for as long as the speed is above 3 km/h (2 mph).

Figure 3

1. Control light, warns for malfunction in primary steering system

2. Control light, indicates that secondary steering pump starts

The following will happen:

 Secondary steering pump starts

 Warning is shown on information display
 Red warning light, low steering pressure, is activated
 Central warning flashes
 Buzzer sounds
If only the differential pressure monitor SE601 closes the switch, this means that the secondary steering pump starts if the
speed is above 3 km/h (2 mph).
The following will happen:

1. Secondary steering pump starts

2. Amber warning light LC16, secondary steering pump, is activated

WARNING
Low
Steering System
Oil Pressure

In case of sensor malfunction

SE403, travel speed considered to be >3 km/h (2 mph).
SE201, engine rpm considered to be 0 rpm (0 rpm).
SW601, considered not active.
SE602, steering pressure considered to be low.
SE601, differential pressure considered to be low.
Electrical functions, description
See wiring diagram 16. The V-ECU is supplied with voltage via fuse FU30, sensor SE601, pin EA22, and SE602, pin EA8. The I-
ECU, pin P2.5, is supplied with voltage via switch SW601.

From the V-ECU, pin 3, the spool on relay RE601 receives current.

Figure 4

1. Control light, warns for malfunction in primary steering system

2. Control light, indicates that secondary steering pump starts

Via relay RE601, current is supplied to the secondary steering pump MO601 and the control light (amber) LC16 in the
instrument panel.
Figure 5
Wiring diagram 16

Hydraulic functions, description

Valve with differential pressure monitor SE601, see also hydraulic diagrams.
Valve and function diagram shows situation before start.
Before start, the peg 5 is kept in place by spring 3 via guide 4 and the piston 2, which means that sensor SE601 is closed.
Pressure monitor SE602 is closed.
After start, SE602 is open as long as the steering pressure is above 0.95 MPa (138 psi).
When the engine starts, the peg 5 is pressed against the guide 4, the spring 3 and the piston 2 (against SE601).
The LS-pressure enters the valve via connection LS and attempts to press the piston in the opposite direction. When the
difference between steering pressure and LS-pressure is greater than 0.7 MPa (102 psi), the spring will be compressed and
the piston opens the monitor SE601.
The LS-pressure also affects the piston 2 directly and when the LS-pressure exceeds 7 MPa (1015 psi), the piston will open
the monitor, independent of the pressure.
The secondary steering starts if the machine's travel speed is above 3 km/h (2 mph) and the pressure difference between the
steering pressure and LS-pressure is less than 0.7 MPa (102 psi) and the LS-pressure is lower than 7 MPa (1015 psi).
NOTE!
When the LS-pressure decreases, the need for differential pressure increases so that the secondary steering doesn't start.
Figure 6
Differential pressure valve

Figure 7
Hydraulic diagram, steering with CDC and secondary steering (larger diagram, see Section 9)

B Hydraulic oil pump, P2, brake, steering, servo and working hydraulics
C Hydraulic oil filter
D Central block
F Valve block
H Steering valve
I Electric motor, pump, secondary steering
J Sensor block, secondary steering
K CDC
 Service Information

Document Title: Function Group: Information Type: Date:

Function test, secondary 647 Service Information 2014/4/28
steering
Profile:
WLO, L90E [GB]

Function test, secondary steering

Function test of the secondary steering system is carried out with a stationary machine and the engine turned off. The
ignition key should be in position 1.

Figure 1
SW601

When switch SW601 is pressed down the connection to the I-ECU is interrupted. When monitors SE602 and SE601 are
closed, the following will happen:

Figure 2

1. Warning lamp, warns against fault in primary steering system

2. Control lamp, indicates that the secondary steering pump starts

1. The secondary steering pump starts up

2. Amber warning lamp LC16, secondary steering pump, lights up

The pump will be running as long as the switch is kept pressed down.
 Service Information

Document Title: Function Group: Information Type: Date:

Comfort Drive Control, 660 Service Information 2014/4/28
description
Profile:
WLO, L90E [GB]

Comfort Drive Control, description

The equipment allows steering, forward–reverse shifting, and Kick-down engagement to be handled with controls located on
the left armrest.

Figure 1
CDC armrest

SE603 Control lever with adjusting screws for steering speed, right and left
SW408 Activating CDC
SW409 Shifting, forward – reverse
SW410 Kick-down
SW407 Switch, CDC operates only when the armrest is lowered
CU601 Electronic unit

On most machines (depending on software) the machine speed can be limited to 30 km/h (19 mph) when lever steering
CDC is engaged, see also 301 Speed limitation for lever steering (CDC).
During transport operations on public roads, the steering wheel must be used and CDC must be disengaged.
The control lever has two adjusting screws for steering speed adjustment.
Electronic unit CU601 (Ramp alternator)
Electronic unit CU601 is not adjustable but has a fixed ramp/damping of approximately 0.2 seconds.
With help from electronic unit CU601, smoother steering is maintained by damping the signal to MA601 both at steering
start and steering stop. Damping (ramp) setting is fixed at approx. 0.2 seconds:
Electronic unit CU601 is designed as a circuit board.
When CDC is engaged, a green control light is lit on the middle instrument panel.
Figure 2
Centre instrument panel

1. Control light, CDC

The control valve, which is connected parallel to the primary steering valve, is located under the cab on the left side of the
machine.
The shuttle valve for LS pressure is located under the cab on the left side of the machine.
The primary gear selector control SW402 is prioritized in relation to the forward–reverse switch SW409 on the armrest. This
means that CDC is disengaged if the gear lever is moved forwards or backwards.
Function
Activating, operation and deactivating
To activate CDC, the armrest must be lowered, which closes SW407. Check that the primary gear control is in the neutral
position while simultaneously rotating the handle to the desired gear position (position 4 is normally selected). Select the
shifting mode with the Mode selector SW412.

Figure 3
Mode selector SW412 is located on the front panel.

CDC is activated with switch SW408 on the armrest. The green control light on the instrument panel should be activated.
Move steering lever SE603 to the desired steering position. Steering speed increases proportionally to the lever deflection.
Move the lever distinctly towards the neutral position when the steering movement is to be stopped.
Select forward, neutral and reverse gear with switch SW409. The Kick-down function is engaged with switch SW410 on the
side of the armrest.
CDC is deactivated by lifting the armrest, opening SW407 or by moving the primary gear selector control SW402 to forward
or reverse position.
 Service Information

Document Title: Function Group: Information Type: Date:

Electrical system, 660 Service Information 2014/4/28
description
Profile:
WLO, L90E [GB]

Electrical system, description

The equipment is connected to connector CDC in the electrical distribution box.

Figure 1
Cables in the electrical distribution box for lever steering.

CDC Connector in the electrical distribution box

1 Cables to armrest
2 Cable run, rear cab wall
OB Connector
OD Connector
31C Chassis connection

Gear shifting forward/reverse, description

See wiring diagram 17.
Feeds are obtained with a started engine.
SW407, SW408 and SW409 fed from FU30.
Relay RE602, connection 30 fed from FU30.
RE602 ensures that lever steering cannot be activated with a raised armrest.
When the armrest is lowered, SW407 closes and the V-ECU receives feed to EA18.
When switch SW408 is actuated and lever steering is activated, the V-ECU receives a voltage pulse to EA4.
The control lamp for lever steering comes on in the instrument panel.
When the engine is started, the V-ECU sends out a feed on EC6 which actuates RE602.
Through RE602 (30–87), the ramp alternators CU601 and MA601 obtain a feed.
Control lever SE603 receives feed via CU601. When the control lever is actuated, a signal (voltage) is sent to steering valve
MA601 via CU601 and steering can be started.
Even 4th gear can be used when lever steering is activated.
If the armrest is raised, SW407 interrupts the feed to EA18 on the V-ECU. When this occurs, the V-ECU interrupts the feed
out form EC6 to RE602 (86).
When RE602 is released, the feed to CU601 and MA601 is interrupted and lever steering is deactivated.
If the primary gear control SW402 is moved to forward or reverse position, the V-ECU will interrupt the feed to RE602 and
the feed to CU601 and SE603.
In order to re-activate lever steering with switch SW408, the armrest must be lowered and the primary gear selector must be
in neutral position.
Kick-down function obtained with SW410.
 Service Information

Document Title: Function Group: Information Type: Date:

Hydraulic system, 660 Service Information 2014/4/28
description
Profile:
WLO, L90E [GB]

Hydraulic system, description

Pump pressure builds up to the steering valve and CDC control valve K. The pressure to the valve slide 15 is reduced to
approx. 12 MPa (1740 psi) by the pressure reducing valve 14.
The pressure limiting valves 18 are blocked in closed position and therefore have no function in the system.
When the stand-by pressure has been accumulated, P2 angles down to “0-flow”.
When the steering lever is activated, an electric signal passes via the ramp alternator CU601 to the control unit in the control
valve. Oil is let in on valve slide 15, which moves and opens to a controlled oil flow to the steer cylinders.
The position sensor sends back signals to the control unit and indicates the slide's position. Oil is let in until the valve slide
has been moved corresponding to the lever deflection.
The pump's flow compensator is affected by the LS pressure and adapts flow to the existing demand.
NOTE!
If steering isn't used, the oil passes from Pump 2 to the servo, brake or working hydraulics. However, steering has priority.

Figure 1
Diagram, CDC, control valve K

MA601 CDC
A Pressure port, steering left
B Pressure port, steering right
T Return to tank via shift valve
P Pressure, inlet
LS LS pressure, outlet
14 Pressure reducing valve
15 Valve slide
16 Anti-cavitation valves
17 Shuttle valve
18 Pressure limiting valves, blocked
Figure 2
Control valve, CDC

14 Pressure reducing valve

15 Control slide
16 Anti-cavitation valve
17 Shuttle valve
18 Pressure limiting valves, blocked
b Non-return valve
 Service Information

Document Title: Function Group: Information Type: Date:

Control valve, description 660 Service Information 2014/4/28
Profile:
WLO, L90E [GB]

Control valve, description

When the steering lever SE603 is activated, an electric signal passes via the electronic unit CU601 to the control unit MA601
(25) on the control valve (11 volt or lower for steering to the left, 13 volt or higher for steering to the right).
Two of the solenoid valves (21–22 or 23–24) in the control unit are activated, which results in oil is let in on one side of the
control slide (15) and it opens to a controlled oil flow to one steering cylinder. The position sensor (27) sends signals back to
the control unit and indicates the slide's position. Oil is let in until the control slide (15) has been moved corresponding to
the lever stroke and desired steering speed has been achieved.
When the slide has assumed the position that corresponds to the signal to the control unit, the control unit cuts off feed to
the solenoid valve (21) or (23) depending on steering direction.
On the control valve's control unit, the light-emitting diode (28) is activated with a green light when steering. If the control
slide jams in the activated position when the lever is returned to neutral position, the diode is activated with a red light. If
such a malfunction occurs, the machine continues to steer even when the steering lever is unaffected.

Figure 1
Control valve with control unit

15 Control slide
21–24 Solenoid valves
25 Control unit with MA601 lever steering CDC
27 Position sensor
28 Light-emitting diode
29 Adjusting screw for position sensor
 Service Information

Document Title: Function Group: Information Type: Date:

Lever steering, adjusting 660 Service Information 2014/4/28
steering speed
Profile:
WLO, L90E [GB]

Lever steering, adjusting steering speed

Op nbr 66003

1. The steering lever has two adjusting screws for adjusting the steering speed. These can be reached by forcing (or
drilling) a hole in the recess in the upholstery on either side of the steering lever.

Figure 1
Arm rest

1. Recess in the upholstery can be found on either side of the steering lever

Figure 2
Adjusting screws for steering speed

A. Steering, left
B. Steering, right

2. Basic setting of steering speed:

4.0–5.0 seconds between full steering locks.
Speed: 1500 rpm
Adjust the steering speed by screwing the adjusting screws clockwise (to increase the speed) or counter-clockwise
(to decrease the speed).
The steering speed to the left and the right should be as equal as possible, and the steering lever must be fully
deflected when carrying out the adjustment.
 Service Information

Document Title: Function Group: Information Type: Date:

Lever steering CDC, 660 Service Information 2014/4/28
checking steering signals
Profile:
WLO, L90E [GB]

Lever steering CDC, checking steering signals

Op nbr 66005

1. Secure the frame joint with the frame joint lock. Block in front of and behind the wheels.

Figure 1

2. Remove the rear cab panel.

3. Start the engine.

4. Lower the armrest and activate lever steering with SW408.

NOTE!
The ordinary gear selector and gear selector on the armrest must be in neutral.

Check-measuring(Ref. 370 Wiring diagram 17)

5. Measure the voltage at connector OD (in cable harness under the circuit board). Leave the connector plugged in.

 The voltage between pin OD4 - OD1 shall be 28 V (system voltage).

 With the steering lever in neutral, the voltage between OD2 - OD1 shall be 13-14 V. Note the value.

6. If any of these values are incorrect, check that fuse FU 30 is intact, part the connector OD and repeat the
measurement. If the values are still incorrect, proceed to step 12.

7. Steer full left with the steering lever and measure the voltage between OD2-OD1. The voltage shall now be
between 6-10 V depending on how the steering lever is adjusted. Note the value.

8. Steer full right and repeat the measurement. The voltage shall now be between 17-21 V depending on how the
steering lever is adjusted. Note the value.
 9. Check how much the measured voltages at full steering deflection, left and right, deviate from the value in neutral
position.The voltage between OD2-OD1Example:

 Neutral position = 14 V.
 Full steering deflection left = 7 V. Difference from neutral position: 14-7 = 7 V
 Full steering deflection right = 20 V. Difference from neutral position 20-14 = 6 V

Excessive voltage difference between right and left may result in different steering speed. Adjust only if the steering
speed is experienced as different. Adjusting, see 660 Lever steering, adjusting steering speed

10. Stop the engine.

Steering lever CU601, checking

11. Loosen the four Allen head bolts under the armrest and turn over the upper part. Do not let the upper part hang by
the cable for the microswitch SW407.

12. Disconnect the black cable at the steering lever. Measure the resistance between black cable, at the steering lever,
and connector OE pin 1. Resistance shall be 0-1 Ω. If not, there is probably an open circuit in CU 601.

Figure 2

13. Start the engine and activate lever steering.

NOTE!
Check that the gear selectors are in neutral.

14. Disconnect white cable at the steering lever. Measure the voltage on the white cable. Voltage shall be 28 V (system
voltage). If there is no voltage, instead measure on the connector OE pin 2. If there is voltage on OE2 but not on
the white cable at the steering lever, there is an open circuit in CU 601.

15. Leave the lever steering activated. Refit the white cable on the steering lever and instead disconnect the green/
black cable.

 Measure the voltage on the middle pin on the steering lever. With the lever in neutral position, the voltage
shall be 13-14 V.
 Move the lever to the left. The voltage should drop to 6-10 V depending on how the steering speed is
adjusted with adjusting screw A.
 Move the lever to the right. The voltage should increase to 17-21 V depending on how the steering speed
is adjusted with adjusting screw B. If the values are incorrect, the steering lever is probably defective.

16. Refit the casing on the armrest. This facilitates installation if the whole armrest is removed and is turned upside
down. Remove the armrest at the joint E.
NOTE!
Do not part the armrest at the fore-aft adjustment D.
 Figure 3

17. Refit the armrest and check that the steering works. Stop the engine.

18. Restore the machine.

 Service Information

Document Title: Function Group: Information Type: Date:

Hydraulic diagram, steering 660 Service Information 2014/4/28
with CDC and secondary
steering
Profile:
WLO, L90E [GB]

Hydraulic diagram, steering with CDC and secondary steering

B Hydraulic oil pump, P2, steering, brake, servo and working hydraulics
C Hydraulic oil filter
D Central block
F Valve block
H Steering valve
I Pump, secondary steering
J Sensor block, secondary steering
K CDC
Figure 1
Hydraulic diagram, steering with CDC and secondary steering
 Thank you for your purchase.
Have a nice day.

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