In my opinion, the best way to start would be to locate and identify the leak. If your A/C system has no refrigerant in it, it has leaked out somewhere. There is also a lubicant in the system called PAG Oil. If the clutch on the compressor is slipping, it's a possibility that the front compressor seal has been leaking and the PAG Oil has contaminated the compressor clutch. The 134a refrigerant is ozone-friendly and resonably inexpensive, so if you add a can and use it to check for leaks; you may be able to visually find the leak if it is a large one. A fill-kit can be purchased at any good auto-parts store for a minimal amount of money. And if it is indeed the compressor seal, a compressor rebuilt kit is probably available. Compressor replacement may not be necessary.

Answered by Dan_K (expert)
224 answers provided

With the engine off does the center of the clutch turn freely?Or is it all bound up?It could be low on charge causing the compressor to cycle.Or the pressures could be too high causing the pressures to cycle.The low side fitting should be a standard r134 fitting.Its not a good idea to just press the a/c valve in doesnt tell you if the system is full and can be dangerous.To properly do this your self you will need to get a r134 gauge set to see what the high and low pressures.

Answered by saturntech9 (expert)
23,190 answers provided