Power Steering Pump Replacement

Introduction

Procedure contributed by Erik Ohrnberger.

Before replacing the power steering pump, confirm it is actually the source of the problem. On the 944, the hoses and reservoir are more commonly the source of power steering fluid leaks than the pump itself. Inspect the high-pressure hose, return hose, and reservoir for seeping or weeping before committing to a pump replacement. If the leak is at a hose fitting or the reservoir, the pump can often be left in place.

If the pump is confirmed as the source — typically a shaft seal leak behind the pulley or a crack in the pump body — proceed with the replacement below.

The owner's manual specifies ATF Dexron as the power steering fluid for this system.

Part references in this procedure follow the factory parts catalogue numbering. Part #26 is the short hose (high pressure, pump to rack); part #39 is the long hose (return line, rack to reservoir). Note that the hose part numbers given here are for a non-turbo 944; turbo cars use different hoses, so confirm fitment before ordering.

Tools

• Standard metric socket set
• Metric combination wrenches
• Belt tension gauge or feeler gauge
• Drain basin
• Rags and fluid catch materials

Procedure

1. Disconnect the negative battery terminal.

2. Remove the lower plastic splash guards to gain access to the bottom half of the engine, and remove the right front plastic inner fender cover for better working room.

3. Place a drain basin beneath the power steering pump. Disconnect the high-pressure hose (part #26) and return hose (part #39) at the pump. Plug or cap the hoses immediately to minimize fluid loss and contamination.

4. Loosen the power steering pump belt tension adjuster bolt. Slip the belt off the pump pulley and set aside.

5. Once the fluid has drained, loosen the two reservoir clamps and remove the two reservoir hoses. Remove the reservoir from the car and clean it thoroughly with mineral spirits, then wash with soapy water and rinse with hot water. Set the reservoir aside and let it dry completely before reinstallation.

6. Remove the pump mounting bolts. There are typically three bolts — two on the adjustment bracket and one pivot bolt. Support the pump with one hand as the final bolt is removed.

7. Lower the pump out of the engine bay. Take care not to spill residual fluid from the pump body.

8. Transfer any brackets or fittings from the old pump to the replacement unit, if not already installed on the new pump.

   Caution: Bolt #8 must be tightened very securely when transferring it to the new pump. If this bolt is not very tight, power steering fluid will leak out.

9. Position the replacement pump on its mounting bracket. Start all mounting bolts by hand before tightening any.

10. Snug the mounting bolts, then install the drive belt. Adjust belt tension so there is approximately 1/4 inch of deflection at the midpoint of the longest belt span under moderate thumb pressure. Torque the mounting bolts fully once belt tension is set.

11. Reconnect the high-pressure hose (part #26) and return hose (part #39) to the pump. Ensure the hose ends seat fully and fittings are hand-tight before applying a wrench. Do not cross-thread.

12. Fill the power steering reservoir with ATF Dexron to the maximum mark.

13. Reconnect the negative battery terminal.

14. Start the engine and allow it to idle. Slowly turn the steering wheel lock-to-lock several times to purge air from the system. Check the reservoir level and add fluid as needed. Continue until no bubbles are visible in the reservoir and steering feel is smooth and consistent.

15. Check all hose connections and fittings for leaks with the engine running. Shut off the engine and recheck the fluid level.

16. Lower the car so there is some weight on the front wheels, then turn the steering wheel lock-to-lock again to stress the power steering system. Raise the car back up and inspect once more for leaks, retightening hose clamps as needed.

17. Refit the right front plastic inner fender cover and the lower plastic splash guards.

Note: A slight amount of seepage at freshly tightened hose fittings may appear on the first drive. Recheck and retorque if needed after the car has been driven and the system is at operating temperature.

Caution: Do not run the pump with the reservoir empty or the hoses disconnected — this will cause rapid pump damage.