Steering: Testing and Inspection
Checking the fluid level for power steering
Notes on power-steering fluid
Damage to the power-assisted 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 occurring in the hydraulic circuit.
Grunt-like noises that can be heard when the steering is locked, or foam formation in the reservoir indicate a shortage of oil and/or that air has also been sucked in. Before filling the reservoir, any existing leaks must be eliminated on the suction side. Alternatively, the defective part on the pressure side should be replaced.
Use only Pentosin hydraulic fluid in the reservoir. Pentosin can be ordered under the following part number:
Quantity supplied 1 litre = 000.043.203.33.
Checking power-steering fluid level - up to MY 2008
The reservoir is located in the engine compartment.
There are two markings on the dipstick located on the cap. One surface shows the marking "Cold" for the cold engine Cold marking: approx. 20 degrees C, while the other surface shows the marking "Hot" for the hot engine Hot marking: approx. 80 degrees.
Checking power-steering fluid
1. Remove engine compartment cover.
Check the fluid level (Pentosin CHF 11 S) when the engine is stopped and cold - Cold marking: approx. 20 degrees C
2. Start the engine and let it run at idle speed for approx. 20 seconds. Switch off the engine.
3. Open engine cover. Open reservoir cap.
4. Wipe off the dipstick. Close and then reopen the cap. The fluid level should be in the hatched area beneath the "Cold" marking (marking = max. level) at Cold marking: approx. 20 degrees C.
Top up with Pentosin if necessary. The upper "Hot" marking is intended for a fluid temperature of approx. 80 degrees C. temperature.
Do not add too much Pentosin! The respective marks are for the maximum fluid level at the "COLD" or "HOT" temperature.
If assembly work was performed previously, check fluid level with the engine idling and without operating the steering.
Multiple steering movements (maneuvering) with the engine switched off change the fluid level in the reservoir fluid level rises. In this case, the engine must be run for at least 20 seconds immediately prior to the fluid level check.
When topping up or filling in Pentosin, make sure that it does not come into contact with the coolant hoses! If coolant hoses come into contact with Pentosin, thoroughly clean them with water IMMEDIATELY! Replace visibly swollen coolant hoses!
5. Close the cap carefully.
6. Fit engine compartment cover.
Checking the steering system for leaks (visual check)
With engine idling, turn steering wheel as far as the stop and hold still. The maximum possible line pressure results in this way.
In this position, check all pipe connections for leaks.
Perform the check for a maximum of 10 seconds. A longer check should always be interrupted by a brief pause after approx. 10 seconds.
Bleeding the steering system
1. To fill the whole system after the installation of new steering components or lines or after a substantial loss of hydraulic fluid, briefly start the engine a few times and, when it fires, switch it off again immediately. This procedure causes the fluid level in the reservoir to fall rapidly, so constantly add more Pentosin. The reservoir must not be sucked dry.
2. 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.
3. Rapidly turn the steering wheel from full-lock to full-lock several times so that the air can escape from the cylinders. At the end positions of the piston, do not pull the steering wheel with more force than is necessary in order to turn the steering (to prevent unnecessary build-up of pressure initially).
4. Observe fluid level during this procedure. If it continues to fall, add fluid until the level in the reservoir remains constant and no more air bubbles rise in the reservoir when the steering wheel is turned.
5. Correct the fluid level with the engine at idling speed and without moving the steering.