Service Information
Document Title: Function Group: Information Type: Date:
Steering system, 600 Service Information 2014/3/11
description
Profile:
CWL, L45B [GB]
Steering system, description
The machine has hydrostatic Load Sensing (LS) articulated steering with two double-action steering cylinders and damped
sideways oscillation.
The steering pump is a gear pump with priority valve.
Figure 1
Steering system, principle illustration
1. Steering unit
2. Hydraulic oil tank
3. Steering pump
4. Accumulator charge valve
5. Steering cylinder
Service Information
Document Title: Function Group: Information Type: Date:
Steering system, 640 Service Information 2014/3/11
troubleshooting and
elimination
Profile:
CWL, L45B [GB]
Steering system, troubleshooting and elimination
General
The table below should help operators and maintenance staff determine the possible cause of a malfunction in the steering
system before damage occurs. It does not claim to be complete, but serves merely to support troubleshooting and
diagnosis. The column "Malfunction/error" contains defective functions or malfunction symptoms which can occur in
practice. The column "Possible malfunction cause" lists assemblies, operating media or states which may cause the
malfunction.
The malfunction is located or eliminated by testing or changing the components specified in the column "Malfunction
elimination".
Malfunction/Error Possible malfunction cause Malfunction elimination
The steering wheel is difficult to Insufficient oil pressure. Too little oil in the hydraulic oil tank, add oil.
turn. The pump does not work. Carry out a function test.
Pump faulty. Change pump.
Pump is worn out. Change pump.
The pressure limiting valve stays open, Repair the pressure limiting valve or remove
or the setting is too low. dirt, adjust pressure limiting valve.
Constant corrections with the Spring force of steering unit too low, Change steering unit.
steering wheel (snaking drive). spring broken.
Spring in double safety valve broken. Replace faulty parts.
Gear worn. Change steering unit.
A steering cylinder has seized or the Replace faulty parts.
piston seals are worn.
Steering wheel does not return Steering column and steering unit are Centre the steering column with the steering
to neutral, there is a tendency to fitted with distortion. unit.
pull to one side. Insufficient or no play between steering Adjust play, if necessary shorten spline pins.
column and steering unit.
Inner and outer sliders on steering unit Change steering unit.
are sticking.
The steering wheel continues to Spring force of steering unit too low, Change steering unit.
turn on its own. spring broken.
Inner and outer sliders on steering unit Change steering unit.
are sticking, possibly dirty.
Steering wheel play The propeller shaft is worn or broken. Change steering unit.
Spring force of steering unit too low, Change steering unit.
spring broken.
Work spline on steering column. Replace steering column, if necessary replace
steering unit.
Tyre vibration during steering Air in steering cylinders. The reason for the air collection must be
process. found and eliminated.
Mechanical connections are worn (run Replace faulty parts.
out).
The steering wheel can be No oil in tank. Add oil and bleed system.
turned continuously without The steering cylinders are worn. Replace worn parts.
giving any steering movement.
Worn gear set. Change steering unit.
Pressure limiting valve set higher than Adjust pressure limiting valve to spec. sheet.
double safety valves.
The steering wheel is too slow The steering unit is not getting enough Replace pump, check engine speed, adjust as
or heavy to move for quick oil, the pump is faulty. in data sheet.
turns. The pressure limiting valve is set too Adjust pressure limiting valve to spec. sheet.
low.
The pressure limiting valve sticks, dirty. Clean the valve.
"Kick–back" in steering wheel Faults in system. Please contact Customer Service.
from the system, jerks from the
wheels.
Strong impact in steering wheel Incorrect adjustment of propeller shaft Change steering unit.
to both sides. and gear set.
When the steering wheel is The hydraulic hoses to the steering Check hoses and connect correctly.
turned, the steering movement cylinders are mixed up.
takes place in the opposite
direction.
Hard point at start of turn of Oil too thick (cold). Check oil, change if necessary. Run engine
steering wheel. until the oil is warm.
Insufficient control force The pump output is too low. Check pump, replace if necessary.
(possibly only on one side). Steering cylinder faulty. Replace steering cylinder.
Leaks from: input shaft, end cap, Faulty shaft seal. Replace shaft seal.
gear set or casing, or upper Loose bolts. Tighten bolts with the prescribed torque.
part.
Washers or O–rings are faulty. Replace faulty washers or O–rings.
Abnormal noise Suction–return filter in hydraulic oil tank Replace filter insert.
dirty
Steering pump draws in air. Eliminate leaks.
Oil level in hydraulic oil tank too low. Add hydraulic oil and bleed steering unit.
Lines chafing. Route lines properly and attach, or replace.
Oil loss on hydraulic steering unit. Replace hydraulic steering unit.
Continued turning and/or Oil level in hydraulic oil tank too low. Eliminate leak, add hydraulic oil and bleed
catching on rapid steering steering system if necessary.
movements.
Steering wheels moves to left or Suction–return filter in hydraulic oil tank Replace filter insert.
right on its own. dirty
Return line to hydraulic oil tank dirty. Change return line, return pressure at 60 °C
≤6 bar (87 psi).
Steering wheel can be turned Internal leakage in hydraulic steering Check slip on steering wheel, replace steering
further when front and rear unit too great. unit if necessary.
parts stop. Internal leakage in steering cylinders too Check internal leakage on cylinders, replace
great. sealing rings or replace steering cylinders if
required.
Service Information
Document Title: Function Group: Information Type: Date:
Hydraulic diagram, steering 640 Service Information 2014/3/11
system
Profile:
CWL, L45B [GB]
Hydraulic diagram, steering system
Figure 1
Hydraulic diagram, steering system
1. Steering valve (ORBITROL)
2. Steering pump
3. Accumulator charge valve
4. Steering cylinder
P Pressure connection, steering pump
L Pressure connection, steering cylinder ground side
R Pressure connection, steering cylinder rod side
T Return, hydraulic oil tank
LS Load Sensing Signal
Service Information
Document Title: Function Group: Information Type: Date:
Steering system, checking 645 Service Information 2014/3/11
and adjusting working
pressure
Profile:
CWL, L45B [GB]
Steering system, checking and adjusting working pressure
Op nbr 645-028
11666020 Pressure gauge
11666037 Hose
Test
1. Run the machine until a hydraulic oil temperature of 55 + 5°C (131 + 41°F) is reached.
2. Connect pressure gauge to test connection on steering pump.
Figure 1
3. Start engine and run at low idle.
4. Turn the steering clockwise or anticlockwise to the end position of the articulated steering, and check the steering
pressure.
Steering pressure nominal value: see Specifications
NOTE!
If the specified nominal value is not reached, set steering pressure on the steering valve (ORBITROL).
5. Adjustment
Remove steering column trim in cab.
6. Unscrew plug on pressure limiter valve and remove seal ring.
Figure 2
Plug - pressure limiting valve
7. Turn pressure limiter valve adjusting screw to left until the pressure gauge shows the nominal value.
Turn to right: increase pressure
Turn to left: reduce pressure
Figure 3
Pressure limiter valve, adjustment screw
8. Screw in plug with seal ring and tighten with a torque of 50 Nm (36.8 lbf ft).
9. Refit steering column trim in cab.
Service Information
Document Title: Function Group: Information Type: Date:
Steering valve, 645 Service Information 2014/3/11
reconditioning (removed)
Profile:
CWL, L45B [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
Many thanks for your purchase.
Happy every day.
file:///C|/Users/yeqiwen/Documents/QIWEN-YE-END.txt[2014/3/11 18:55:56]
