K 2500 Suburban 4WD V8-454 7.4L VIN N TBI (1995)
Compressor Shaft Seal: Testing and Inspection
1. Blow shop air behind and in front of the compressor clutch/pulley for at least 15 seconds.
2. Wait 1-2 minutes.
3. Probe the area in front of the pulley. If the detector goes to a solid alarm, a leak has been found.
5. If possible, visually inspect the core face with a flashlight for evidence of refrigerant oil.