Power Steering Pump: Service and Repair
Removing and installing hydraulic pumpTools
General
Position of hydraulic pump on engine
Damage to the power steering will occur if there is 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.
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.
Preliminary work
Note: The engine does not need to be removed to remove and install the hydraulic pump.
Note: Cayenne Turbo only: Before removing the cover of the air cleaner box, the intake manifold of the turbocharger must be disengaged from the air cleaner housing. * Loosen the pulley of the hydraulic pump before removing the drive belt.
1. Remove left front wheel.
2. Remove engine guard.
3. Remove front left wheel housing liner. Once the air cleaner housing is removed -Arrow- access to the engine compartment becomes available.
4. Remove the left engine compartment cover.
Removing hydraulic pump (Cayenne Turbo/Cayenne S)
Note: The engine does not need to be removed to remove and install the hydraulic pump. Hydraulic pump (pulley removed)
1. Pull the cover of the throttle body up and off.
2. Remove air box for throttle housing (Y-pipe).
Note:
^ Cayenne Turbo only: Before removing the cover of the air cleaner box, the intake manifold of the turbocharger must be disengaged from the air cleaner housing.
^ Loosen the pulley of the hydraulic pump before removing the drive belt.
3. Remove the left air cleaner housing. To do this, follow points 4 and 5 -Air path on Cayenne Turbo (left side)-. Points 5 to 11 are not relevant for the Cayenne S.
4. Disconnect intake manifold at the air cleaner cover.
5. To do this, turn the -pins 180°- and pull them out. Then pull off the intake manifolds.
6. Once the cover is removed, remove the intake manifold completely along with the clamp. To do so, disconnect the positive crankcase ventilation pipe at the pressure pipe -Arrow- and at the hydraulic pump -Arrow- (clamp locks).
7. Separate the pressure pipe at the turbocharger and at the charge air cooler from below (engine guard removed).
8. Loosen pulley on hydraulic pump. Do so by slackening the drive belt -see illustration- and set it aside.
9. Remove pulley on hydraulic pump completely.
10. Clamp both lines to the hydraulic pump (suction line, pressure pipe) with a hose clamp 3094 as close as possible to the pump.
11. 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.
12. Remove the hydraulic pump (3 x front Torx E12, 1 x rear Torx E12).
Installing hydraulic pump (Cayenne Turbo/Cayenne S)
Note:
^ In vehicles without Servotronic, the hydraulic system must be flushed with approximately two liters of Pentosin.
^ The hydraulic system must be bled after repair ->48 Test and assembly work on power steering'. The 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.
^ When replacing the hydraulic pump observe the instructions in the Technical Information, Replacing servo pump.
^ Observe correct tightening torques.
1. Fit hydraulic pump. Tightening torque 17ft. lbs.
2. Fit pulley on the hydraulic pump and screw in the screws.
3. Fit drive belt in correct position and tension.
4. Tighten the pulley on hydraulic pump. Tightening torque 17 ft. lbs.
5. Fit both hydraulic lines. Tightening torque 22 ft. lbs. ± 2.0 ft. lbs. Tightening torque 7.5 ft. lbs..
6. Fit the pressure pipe on the turbocharger and on the charge air cooler. Connect positive crankcase ventilation pipe at the pressure pipe and at 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 air box for throttle housing (Y-pipe).
9. Fit the air cleaner element and the cover for the air cleaner housing.
10. Fit intake manifold on cover for air cleaner housing.
11. Insert wheel housing liner.
12. Disconnect pressure pipe on the servo oil cooler (line leading to the hydraulic fluid tank). Have a suitable plug ready and close the line (emerging hydraulic fluid!). 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 flushing 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. The vehicle must be lowered onto the wheels for this. The tank must not run 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. ->48 Test and assembly work on power steering'
Subsequent work
1. Fit the wheel and tighten to the specified tightening torque .
2. Fit the engine guard.