Flushing The Steering System

Information 

The following components of the steering system must also be replaced on all vehicles:

• Reservoir 
• Suction hose from reservoir to hydraulic pump (referred to as "suction hose" in the text) 
• Return line from steering fluid cooler to reservoir (referred to as "return line" in the text) 

If a fluid-carrying component of the steering system was replaced, the steering system must be flushed with approx. 3 - 4 liters of steering fluid. This will flush impurities, resulting from defective components and/or wear, out of the steering system. A second mechanic is required for some of the repair work.

Work preparation: Hose (shop-made) 

Return line extension, for draining steering fluid.

Length of hose (shop-made) for return line extension

• > Internal diameter + 12 mm + 3 mm
• > Length + 1, 700 mm + 300 mm

1. Remove engine guard and place a suitable container underneath for collecting steering fluid, e.g. a 10-liter canister.

   > 108019 REMOVING AND INSTALLING ENGINE GUARD

2. Disconnect return line -1-  at the steering fluid cooler and drain steering fluid.

   Fit return line again after draining the steering fluid.

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Fluid cooler lines: 1 - return, 2 - supply

3. Remove cover on lock carrier and trim panel in the engine compartment at the left.

   > WM 700219 REMOVING AND INSTALLING FRONT TRIM PANEL (ENGINE COMPARTMENT) (CAYENNE, CAYENNE GTS, CAYENNE TURBO S, CAYENNE S, CAYENNE S E-HYBRID, CAYENNE TURBO, CAYENNE S DIESEL, CAYENNE (3.0))

4. Disconnect the return line at the reservoir -4-  .

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Reservoir (1), suction hose (3) and return line (4)

5. Remove single-lug clamp between the short rubber hose and rigid line. Then pull off the short rubber hose.

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Removing short rubber hose from rigid line

6. Fit the hose (shop-made) onto the rigid end of the return line.

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Fitting hose (shop-made)

   Guide the other end of the hose (shop-made) into the steering fluid collection container.

   Information 

   Use a sufficiently large container to collect steering fluid, e.g. a 10-liter canister.

   • Secure the free end of the hose (shop-made) in the collection container (strong flow of fluid). 

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Hose (shop-made) 1

7. Replace and fit suction hose -3-  and reservoir -1-  .

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Reservoir (1), suction hose (3) and return line (4)

8. Close off connection piece for the return line -4-  at the reservoir.
9. Fill the reservoir up to the MAX marking until the fluid level no longer drops.

   Engine is not started! 

10. Raise the vehicle until the wheels are no longer touching the floor. Turn the steering fully to the left and right and hold it at full lock for approx. 30 seconds on each side until the level no longer drops. Continually check the fluid level and fill to the MAX marking again.
    CAUTION: Escaping (spraying) Pentosin 

    • Risk of skin and eye irritation 
    • Swollen water hoses 
      1. Wear protective gear (goggles, gloves).
      2. If water hoses come into contact with Pentosin, clean them thoroughly with water IMMEDIATELY.
      3. Swollen water hoses must be replaced.
11. Procedure for flushing the steering system 

    The vehicle must be standing on its wheels.

    1. 11.1 - Have a can containing approx. 3 - 4 liters of steering fluid ready. First mechanic continually checks the fluid level in the reservoir and checks that Pentosin flows safely into the container.

       The reservoir must not run dry!

       NOTE: NOTIFICATION 
       Rotating components 

       • Danger of limbs being trapped or severed 
         1. Do not reach into rotating parts.
         2. Do not start the engine until the second mechanic has clearly confirmed that it is safe to do so.
    2. 11.2 - Second mechanic  sits in the vehicle and

       starts the engine for max. 1 second following consultation with the first mechanic. 

    3. 11.3 - Second mechanic  must also start turning the steering to the left and right at full lock on either side.
    4. 11.4 - Stop the engine IMMEDIATELY after flushing the system for 1 second! Fill the can with steering fluid if necessary and check the flow in the collection container (secure it to prevent it from slipping out!).
    5. 11.5 - Check the fluid level in the reservoir and continually top it up each time the engine is started. Then restart the engine several times following consultation with the first mechanic  until the steering fluid (3 - 4 liters) you are using to flush out the system has been flushed through.

    Then stop the engine IMMEDIATELY.

12. Once the flushing process is complete, remove the hose (shop-made).
13. Fit new return line.
14. Bleed the steering system and correct the fluid level in the reservoir.

    >4890IN TEST AND ASSEMBLY WORK ON POWER STEERING 

15. By shining a torch in the reservoir, check for shimmering metal particles (like metallic paint) in the steering fluid. Don't confuse these with air bubbles! If metal particles are visible, flush the system again.
16. Install cover on lock carrier and trim panel in the engine compartment at the left.

    > WM 700219 REMOVING AND INSTALLING FRONT TRIM PANEL (ENGINE COMPARTMENT) (CAYENNE, CAYENNE GTS, CAYENNE TURBO S, CAYENNE S, CAYENNE S E-HYBRID, CAYENNE TURBO, CAYENNE S DIESEL, CAYENNE (3.0))

17. Fit engine guard.

    > 108019 REMOVING AND INSTALLING ENGINE GUARD