Power Steering Pump: Service and Repair

Removing and installing hydraulic pump (Cayenne Turbo/Cayenne S)





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 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.

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 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.





Hydraulic pump (belt pulley removed)

1. Remove left front wheel.





2. Remove engine guard.





3. Remove front left wheel housing liner. The engine compartment can be accessed once the -air cleaner housing (arrow)- is removed.
4. Remove left engine compartment cover.





5. Pull the cover of the throttle body vertically upwards.
6. Remove cowl for throttle body (Y-shaped pipe).

Note!
^ Cayenne Turbo only: Before removing the air cleaner compartment lid, the intake manifold of the turbocharger must be disengaged from the air cleaner housing.
^ Loosen the belt pulley of the hydraulic pump before removing the drive belt.





7. Remove the left air cleaner housing.





8. Disconnect intake manifold on air cleaner lid. Remove the air cleaner cover on the Cayenne S.





9. To do this, turn the pins 180° and pull them out. Then pull off the intake manifolds.





10. Once the lid is removed, remove the intake manifold completely along with the clamp. To do so, disconnect crankcase venting pipe at the pressure pipe and up to the hydraulic pump (clamp locks).





11. Separate the pressure pipe on the turbocharger and on the charge air cooler (engine guard removed).





12. Loosen drive belt on hydraulic pump. To do this, -relieve tension on drive belt- and set it aside.
13. Remove belt pulley on hydraulic pump completely.
14. Clamp both lines to the hydraulic pump (suction line, pressure pipe) as close as possible to the hydraulic pump using a hose clamp 3094.
15. 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.





16. Remove the hydraulic pump (3 x front Torx E12, 1 x rear Torx E12).

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 (22 ft. lbs.) ± 3 Nm (2 ft. lbs.), M6 screws 10 Nm (7.5 ft. lbs.)). Remove hose clamps 3094.
6. Fit the pressure pipe on the turbocharger and on the charge air cooler. Connect crankcase venting pipe at the pressure pipe and up to the hydraulic pump (not Cayenne S). Position heat shield.
7. Fit intake manifold on the turbocharger (not Cayenne S) and install air cleaner housing.
8. Fit cowl for throttle body (Y-shaped pipe).
9. Fit the air cleaner element and the lid for the air cleaner housing.
10. Fit intake manifold on air cleaner housing lid.
11. Install wheel housing liner.
12. 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.
13. 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).
14. 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).
15. Fit the pressure pipe on the servo oil cooler.
16. 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.
17. Fit the wheel and tighten to the prescribed tightening torque.
18. Install engine guard.