Test and Assembly Work on Power Steering
Test and assembly work on power steeringGeneral
General
Note: Rack-and-pinion steering gear and servo pump must not be repaired or dismantled!
Damage to the power steering is caused by a shortage of oil in the hydraulic system. Even small leaks can cause the fluid to escape and damage the servo pump as a result of the high oil pressure in the hydraulic circuit.
Grunt-like noises on turning the steering to full lock or foam formation in the reservoir indicate a shortage of oil and/or the absorption of air. Before filling the reservoir, any existing leaks must be eliminated . In this case the oil level in the reservoir must be checked with the engine running as well as stopped! If the oil level drops to the bottom of the reservoir or bubbles rise up, then there is air in the hydraulic system.
Use only Pentosin CHF 11 S in the reservoir. Pentosin CHF 11 S can be ordered under the following part number: Quantity supplied 1 liter = 000.043.203.33.
A dipstick with a MAX/MIN marking is mounted on the reservoir cap -> see figure. The marks are for a fluid level with a cold engine (approximately 20 °C)!
Checking fluid level for power-assisted steering
Checking fluid level for power-assisted steering
ATTENTION: Increased risk of accident and material damage if too much Pentosin CHF 11 S is filled in or if Pentosin CHF 11 S comes into contact with the coolant hoses when filling or topping up.
^ Overfilling of the system with consequent overflow of Pentosin CHF 11 S onto coolant hoses and other components may occur.
-> Before inspecting the fluid level, run the engine for approximately 20 seconds. Multiple steering operations (maneuvering) will alter the fluid level in the reservoir! Check the fluid level.
-> If coolant hoses come into contact with Pentosin, thoroughly clean them with water IMMEDIATELY.
-> Replace visibly swollen coolant hoses.
Note:
^ The reservoir is located at the front left of the engine compartment.
Pentosin tank in the engine compartment
^ A dipstick with MAX-MIN marks is mounted on the cap of the reservoir. They are for a fluid level with a cold engine (approximately 20°C).
^ The MAX mark can easily be exceeded at higher temperatures.
Check the fluid level (Pentosin CHF 11 S) when the engine is stopped and cold (approximately 20°C).
The fluid level must be between the MAX and MIN marks -> see figure.
1. Start engine and run it at idle speed for approximately 20 seconds. Switch off engine.
2. Open engine cover and the lid of the engine compartment cover.
3. Open reservoir cap.
4. Wipe dipstick. Close and then reopen cap. The fluid level must be in the indicated range (MAX/MIN level at approximately 20 °C). Top up with Pentosin if necessary.
Bleeding the steering system
Bleeding the steering system
1. After installation is complete, raise the vehicle so that the wheels are no longer touching the ground.
2. Open engine cover, lid and reservoir.
3. Fill reservoir up to the MAX mark, until the level no longer drops.
4. Then turn the steering to the left and to the right. Hold the steering on full lock for approximately 30 seconds on each side until the level no longer drops. Continually check the fluid level and fill to the MAX mark again if necessary.
5. Lower vehicle onto the wheels. Briefly start the engine, let it run for approximately 1 second and add Pentosin again. This procedure causes the fluid level in the reservoir to fall rapidly, so constantly add Pentosin CHF 11 S. The reservoir must not be sucked dry.
6. If the fluid level in the reservoir does not fall any further when the engine is briefly turned over, start the engine and let it run at idling speed.
7. Turn steering on full lock several times to left and right at idling speed and observe the fluid level during this procedure (second worker required). If it continues to fall, add fluid until the level in the reservoir remains constant and no more air bubbles circulate in the reservoir when the steering wheel is turned.
8. Switch engine off and set the correct fluid level. This must be between the MAX and MIN markings.
When the correct level has been reached, no air bubbles must be circulating in the reservoir and the fluid level must no longer drop.