My A/C compressor clutch seems to be alternating between slipping and running when refrigerant is cycling thru the system. When the clutch slips it makes a sort of whining noise. Does this mean my compressor's clutch has gone bad? Can you replace just the clutch or do you need to replace the entire compressor?

Van is a '93 B150 3.9L if that matters.

Check the belt tension first. If the belt is loose that will cause the whining noise you are hearing. Does it do this at idle, when stepping of the gas, or only when the clutch engages?

You may want to check the voltage at the clutch it self. If the ground is not real good or if the power wire does not have sufficient voltage that may cause the clutch not to fully engage.

Most times it is better to replace the whole compressor than just the clutch. How old is the AC compressor? If over a year old it would be better to get a new complete unit, if that is the problem.

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I do Mobile Automotive Repair and use Mitchell On Demand 5.8
1997 B2500 Custom(izing) Cargo Van, 3.24:1, 5.2L, 35 Gal. tank, 333K total miles. Check out my photos: http://dodgeforum.com/forum/album.php?u=88523
1977 Impala Sedan, 5.0L, 72K total miles.

I figured out the problem - sort of. There was too much refrigerant in the system and the compressor could not push it properly, so it was slipping. Over the weekend the R134a busted out of the system witha loud WHOOSH and now the compressor is no longer running. No refrigerant=no pressure=no A/C.

So now my question is: does this A/C system have a relief valve or did I blow a gasket or o-ring somewhere?

A relief valve would've just blown off the excessive pressure then closed. Most likely you blew out a seal.

Look for refrigerant oil and that will mostlikely be the part that blew out the seal. I hope it was not the compressor.

__________________
I do Mobile Automotive Repair and use Mitchell On Demand 5.8
1997 B2500 Custom(izing) Cargo Van, 3.24:1, 5.2L, 35 Gal. tank, 333K total miles. Check out my photos: http://dodgeforum.com/forum/album.php?u=88523
1977 Impala Sedan, 5.0L, 72K total miles.

Noise came from directly under the engine cover. Scared the bejeezus out of me. I see a wet/oily area directly behind the compressor. Refrigerant lines all seem to be in tact.

You may have just blown the seals for where the lines connect to the compressor. If so just replace the o-rings, vacuum down the system and refill with the proper amount of R134-a and that should solve it.

__________________
I do Mobile Automotive Repair and use Mitchell On Demand 5.8
1997 B2500 Custom(izing) Cargo Van, 3.24:1, 5.2L, 35 Gal. tank, 333K total miles. Check out my photos: http://dodgeforum.com/forum/album.php?u=88523
1977 Impala Sedan, 5.0L, 72K total miles.