How to Replace the A/C Compressor Shaft Seal
The A/C compressor shaft seal keeps dirt and water out of the auto A/C compressor, so when the seal is broken, the quality of air from the car's A/C unit will be affected as well as the performance of the compressor. So if you notice any signs of leaks or excessive noise from your car's A/Ccompressor, check the seal and have it replaced if necessary.
Difficulty level: Moderate to Difficult
- Crescent wrench
- Snap ring pliers
- Clutch assembly puller tool (situational)
Step 1: Get the Freon gas from the A/C unit discharged by a qualified technician. Make sure both the A/C unit and engine are turned off while discharging.
Step 2: Using a crescent wrench, disconnect the battery cable and the electrical wiring harness from the compressor. Detach the drive belt from the compressor pulley.
Step 3: Take out the refrigerant lines connected to the compressor. With the hoses are out of the way, remove the mounting bolts from the compressor mounting bracket. Have someone to hold the clutch assembly steady while you remove the nuts. Note: Check the direction of the threads. Some compressor mounting bolts have left-handed threads that can get damaged if turned the wrong way.
Step 4: Once you have removed the mounting bolts, lift the clutch out of the vehicle. In some car models, you may have to use a special clutch assembly puller tool to pry the clutch out. The puller tool resembles a combination nut and bolt and threads directly into the clutch assembly. The bolt runs through the center and pushes against the compressor shaft, forcing the clutch to move away and off the compressor.
Step 5: Remove the housing bolts under the compressor, open the compressor housing and carefully slide out the seal from the compressor shaft. If the seal is held in place by a large retaining ring, use a pair of snap ring pliers to grip and pull out the ring. Carefully take the seal out.
Step 6: Clean the seal area and install the new seal into the compressor.
Step 7: Replace the housing, the housing bolts and the clutch. Make sure that there is a proper air gap between the clutch and the hub (you can check with the manufacturer for the optimal gap). Attach the refrigerant lines, compressor belt, and other components you've removed previously.
Step 8: Have the A/C system recharged with refrigerant and start the engine. Let it run for a few minutes to check if the A/C is working properly again.
- Do not use an air wrench or similar pneumatic tools when working with the A/C compressor and clutch assembly. These parts are usually made from aluminum and could be damaged if over-tightened.