Power Steering Pump: Service and Repair
Removing and installing hydraulic pump (Cayenne V6)
Position of hydraulic pump on engine
General
Damage to the power steering is caused by a shortage of oil in the hydraulic system. Even small leaks can cause the hydraulic fluid to escape and damage the servo pump as a result of 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.
Caution! Danger of damage to property if too much Pentosin CHF 11 S. is filled or if Pentosin CHF 11 S comes into contact with the coolant hoses when filling or topping up.
^ Observe the following specifications in order to avoid overfilling and thus overflowing.
^ The engine must be run for approximately 20 seconds prior to the fluid level check. Multiple steering operations (maneuvering) change 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.
Removal
Note!
^ The engine does not have to be removed in order to remove and install the hydraulic pump.
^ The hydraulic pump in the V6 engine is accessible from beneath.
Hydraulic pump (belt pulley removed)
1. Remove left engine compartment cover.
Note!
^ Before removing the air cleaner compartment lid, the intake manifold must be disengaged from the air cleaner housing.
^ Loosen the belt pulley of the hydraulic pump before removing the drive belt.
2. Disconnect intake manifold on air cleaner lid. To do this, turn the -pins through 180°- and pull them out. Then, set the intake manifold aside.
3. Remove air cleaner.
4. Loosen belt pulley on hydraulic pump, but do not remove it.
5. Slacken the drive belt and remove it from the belt pulley.
6. Lift the vehicle.
7. Remove engine guard.
8. Remove belt pulley.
9. Clamp both lines to the hydraulic pump (suction line, pressure pipe) - as close as possible to the hydraulic pump - using a hose clamp 3094.
10. Remove both lines to the hydraulic pump (suction line, pressure pipe). Close the open connections with suitable plugs. Collect emerging hydraulic fluid in a suitable container.
11. Remove hydraulic pump.
Installation
Note!
^ In vehicles without Servotronic, the hydraulic system must be rinsed with approximately two liters of Pentosin.
^ The hydraulic system must be bled following repair work . Vehicle must be lowered onto the wheels for this.
^ Only use Pentosin CHF 11 S to fill the hydraulic system.
^ Pay attention to the hydraulic fluid level.
^ Replace sealing rings.
^ Observe the information in the Technical Information, Replacing servo pump.
^ Use correct tightening torques.
1. Fit the hydraulic pump (tightening torque: 23 Nm (17 ft. lbs.)).
2. Fit belt pulley of the hydraulic pump and insert screws.
3. Install drive belt in correct position and tighten.
4. Tighten belt pulley on hydraulic pump to 23 Nm (17 ft. lbs.).
5. Fit both hydraulic lines (tightening torque: banjo bolt 30 Nm (22 ft. lbs.) ± 3 Nm (2 ft. lbs.), M6 screws 10 Nm (7.5 ft. lbs.)). Remove hose clamps 3094.
6 .Install air cleaner.
7. Fit intake manifold on air cleaner housing lid.
8. Disconnect pressure pipe on the servo oil cooler (line leading to the hydraulic fluid tank). Have a suitable plug ready for closing the line (hydraulic fluid escapes!). Collect emerging hydraulic fluid in a suitable container.
9. Fill the hydraulic fluid tank. Use a suitable auxiliary hose (approximately 10 - 15 cm, shop-made) to carry hydraulic fluid that emerges during rinsing into a suitable container (approximately 1.5 liters).
10. Rinse the hydraulic system with the engine running by turning the steering several times to the right or left stop, and adjust the hydraulic fluid level several times as required. Vehicle must be lowered onto the wheels for this. The tank must not run on empty while the engine is running (two workers required).
11. Fit the pressure pipe on the servo oil cooler.
12. Bleed the hydraulic system with the engine running by turning the steering several times to the right or left stop, and adjust the hydraulic fluid level several times as required.
13. Install engine guard.