Hydraulic System: Service and Repair

FILLING AND BLEEDING THE H31 HYDRAULIC SYSTEM
Filling with Engine Stopped
- With engine off, remove cover from power steering fluid tank.
- Fill oil level up to (A) = approx. 25 mm (1 in) below upper edge of tank.

Filling and Bleeding with Engine Running
Filling
- Pour in remaining amount of oil uniformly while starting engine. Oil volume:

With Ride Level Control 2.4 L (2.54 qt).

CAUTION: Pay close attention to fluid identification label on fluid tank.

Bleeding
- Turn steering wheel as far as left and right lock 2 times, operate brake pedal 5 times, wait about 30 seconds and operate brake pedal five more times.

Checking Oil Level with Engine Stopped
- With the engine off, operate brake pedal until hydraulic reservoir is empty. The reservoir is empty when oil level in tank no longer rises (visual check) or when suddenly more force is required to press the brake pedal down (force check).

Vehicles without ride level control, oil level must now be about 10 mm (0.39 in) below upper edge of tank.

Vehicles with ride level control, lift rear axle until wheels clear the floor. Oil level must now be max. 5 mm (0.2 in) above bottom of filter screen after 2 minutes (accumulators for level regulation are discharged).

FILLING AND BLEEDING ASC + T OIL CIRCUIT
Filling

CAUTION: Ensure that the brake system is filled with brake fluid before filling mineral oil circuit with hydraulic oil.





- With the ignition switch off, disconnect the ABS/ASC + T control unit electrical connector.
- Follow procedure for Filling and Bleeding the H31 Hydraulic System above.

Bleeding ASC + T Oil Circuit
- Switch "Off" ignition.
- Reconnect the ABS/ASC + T control unit electrical connector.
- Start the engine and run at idle speed for at least 60 seconds (charges ASC + T plunger accumulator).





- Fit special tool 34 3 110 to the bleeder screw (1) on the hydraulic plunger unit and insert end of hose in hydraulic oil tank.
- Open bleeder screw and flush plunger hydraulic unit until hydraulic oil emerges without bubbles (at least 15 seconds).
- Close bleeder screw.
- Recheck hydraulic oil level as before.