Compressor Removal and Installation

Overview

This procedure details how to remove and install the air conditioning (A/C) compressor on a Porsche 944 S / S2 with a 16v engine. The compressor is critical for circulating refrigerant to cool the cabin. Removing and replacing it may be necessary due to clutch failure, leaks, or internal damage. This guide assumes the A/C system uses R134a, as most S / S2 models have been converted from R12. If R12 is present, professional refrigerant evacuation is required before starting.

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Tools Required

• 10mm (3/8 inch) socket and ratchet
• 13mm (1/2 inch) socket and ratchet
• 17mm (11/16 inch) wrench
• Flathead screwdriver
• Torque wrench (covering 20-50 Nm / 15-37 ft-lbs)
• Safety glasses and gloves (nitrile and leather)
• Manifold gauge set (for confirming system evacuation)

Parts Required

• A/C compressor (Sanden SD7H15 for R134a, 944 126 011 02)
• Compressor O-rings (assorted kit, 999 707 162 40)
• PAG-46 oil (100-150 mL, 000 043 305 15)

Step-by-Step Procedure

Step 1: Prepare the Vehicle and Safety Precautions

1. Park the vehicle on a flat surface in a well-ventilated area, away from open flames or sparks.
2. Ensure the engine is off and the A/C system is not running.
3. Wear safety glasses and gloves (nitrile under leather) to protect against refrigerant exposure or pinch injuries.
4. Disconnect the negative battery terminal using a 10mm (3/8 inch) wrench to prevent electrical hazards.

Step 2: Confirm Refrigerant Evacuation

5. Locate the low-pressure port on the compressor (driver’s side wheel well) and high-pressure port near the receiver/drier (near the radiator).
6. Connect a manifold gauge set to both ports and confirm the system is fully evacuated (pressure at 0 bar / 0 psi). If pressure exists, professional evacuation is required.

Step 3: Access and Remove the Compressor

7. Turn the steering wheel fully left to access the compressor through the driver’s side wheel well.
8. Remove the A/C compressor drive belt by loosening the tensioner pulley with a 17mm (11/16 inch) wrench.
9. Disconnect the compressor’s electrical connector by pressing the release tab and pulling gently.
10. Remove the refrigerant lines from the compressor using a 13mm (1/2 inch) wrench, capping the lines immediately to prevent contamination.
11. Remove the four compressor mounting bolts (13mm / 1/2 inch) using a socket and ratchet, and carefully lower the compressor from the engine bay.

Step 4: Prepare the New Compressor

12. Compare the new compressor (944 126 011 02) to the old one to ensure identical fittings and pulley alignment.
13. Add 100-150 mL of PAG-46 oil (000 043 305 15) to the new compressor’s inlet port, per the Porsche 944 Workshop Manual.
14. Install new O-rings (999 707 162 40) on the refrigerant line fittings, lubricating them with PAG oil.

Step 5: Install the New Compressor

15. Position the new compressor in the engine bay and secure it with the four 13mm (1/2 inch) mounting bolts, tightening to 45 Nm (33 ft-lbs).
16. Reconnect the refrigerant lines to the compressor, tightening the bolts to 20 Nm (15 ft-lbs) using a 13mm (1/2 inch) wrench.
17. Reattach the electrical connector to the compressor, ensuring it clicks into place.
18. Reinstall the A/C drive belt and adjust the tensioner pulley with a 17mm (11/16 inch) wrench to achieve proper tension (slight deflection under thumb pressure).

Step 6: Finalize and Test

19. Reconnect the negative battery terminal and tighten to 10 Nm (7 ft-lbs) using a 10mm (3/8 inch) wrench.
20. Inspect all connections for secure fittings and proper alignment.
21. Start the engine and briefly engage the A/C to check for compressor clutch engagement (listen for a click and watch for pulley rotation).
22. Check for leaks at the refrigerant line connections using a UV dye kit or electronic sniffer.
23. Drive the vehicle for 5 miles (8 km) to ensure the compressor operates smoothly without unusual noises.

Post Procedure Checklist

• Verify the compressor clutch engages when the A/C is turned on.
• Check for leaks at all refrigerant line connections using UV dye or an electronic sniffer.
• Ensure the drive belt is properly tensioned with slight deflection under thumb pressure.
• Confirm no unusual noises (e.g., grinding, squealing) from the compressor during operation.
• Check that all bolts are tightened to specified torques (45 Nm / 33 ft-lbs for mounting, 20 Nm / 15 ft-lbs for refrigerant lines).

Sources

• Clark’s Garage
• Pelican Parts
• Porsche 944 Workshop Manual, Volume 1
• Youtube