Checking Power Steering Balance and Pump Pressure
Checking power steering balance and pump pressure
Special tools:
999 5055 Pressure gauge 999 5055 Pressure Gauge
999 5175 NIPPLE 999 5175 Nipple
999 5319 CLUTCH 999 5319 Clutch
999 8081 TORQUE GAUGE 0-6 Nm 999 8081 Torque Gauge 0-6 Nm
998 8695 TEST DEVICE 998 8695 Test Device
Connect the test instrument
Place paper over the generator (GEN) as protection against the oil.
Connect instrument 999 5055 Pressure gauge 999 5055 Pressure Gauge between the pump and the pressure hose from the steering gear housing.
Use nipples 999 5175 NIPPLE 999 5175 Nipple and 999 5319 CLUTCH 999 5319 Clutch.
Close nipple 999 5175 NIPPLE 999 5175 Nipple using the pipe screw and washers from nipple 999 5319 CLUTCH 999 5319 Clutch.
D4192T with air conditioning (AC) system: first remove the inlet hose.
Note! Connect the pipe from the instrument cock to the pressure pipe for the steering gear.The cock should be parallel with the hose.Check the direction of flow.
Position the manometer in the engine compartment so that it can be read off from the driver's seat
Check the oil level in the servo reservoir. Top up if necessary
Remove paper over the generator (GEN).
Start the engine. Allow the engine to idle.
Remove the steering wheel module
Remove:
- the battery negative lead
- the two torx screws on the reverse of the steering wheel module.
Disconnect the connector. Remove the steering wheel module
Connect test dummy 998 8695 TEST DEVICE 998 8695 Test Device.
The test dummy is used to prevent a diagnostic trouble code (DTC) being stored when the engine is started.
Install the battery negative lead.
Checking balance when turning wheel to right
Start the engine.
Turn steering wheel nearly to the right limit position.
Connect torque gauge 999 8081 TORQUE GAUGE 0-6 Nm 999 8081 Torque Gauge 0-6 Nm to the steering wheel screw. Turn the torque gauge slowly to the right. Read off the torque just as the manometer reaches 1.2 MPa (12 bar).
Checking the balance when turning the steering wheel to the left
Turn the wheel nearly to the left limit position. Read off the torque in the same way as for the right-hand side.
Interpreting the torque measurements
The torque must be between 2.8 and 4.0 Nm (28 - 40 kpcm) and must not deviate by more than 0.7 Nm (7 kpcm) between the right and left-hand sides.
Note! If the deviation is excessive, the steering gear housing must be replaced.
Checking the pump pressure
Checking the pump pressure at the left limit position
Start the engine.
Turn the steering wheel to the left. Press to the limit position for a maximum of 10 seconds while reading off the manometer.
Note! Correct pressure: 9.6 MPa (98 bar, Saginaw), 11.0 MPa (110 bar, ZF).
Checking the pump pressure at the right limit position
Turn the steering wheel to the right limit position. Read off the manometer as above.
Check the pump capacity if the pump pressure is incorrect
Shut the cock for a maximum of of 10 seconds. If the pump is not faulty the manometer pressure should rise to the correct value: maximum 9.6 MPa (Saginaw), 11.0 MPa ZF.
If the pressure lies outside the values:
recondition or replace the pump.
Switch off the engine
Install the steering wheel module
Remove:
- the battery negative lead
- test dummy 998 8695 TEST DEVICE 998 8695 Test Device.
Install:
- the connector. Hold the lower part of the steering wheel module on the steering wheel
- the steering wheel module. Tighten both the torx screws. Tighten to 10 Nm.
Check that nothing is trapped and that the steering wheel module is correctly secured.
Remove the test instrument
Place paper over the generator (GEN) as protection against the oil.
Remove the test instrument and nipples.
Connect the inlet hose to the pump.
Use a new O-ring.
D4192T with air conditioning (AC) system: secure the inlet hose using a new tie strap.
Fill and bleed the servo system
Fill the servo reservoir with oil. Bleed the system. See the specifications for the oil grade.
Apply the parking brake. Start the engine.
Turn the steering wheel from lock to lock several times.
Check that the function is OK and that there is no leakage.
Check the oil level. Top up if required.
Note! Power steering fluid, quality ATF F,G, Dexron D/E Ford Mercon