A/C Compressor

[JohnO]

The A/C compressor on my 73 makes alot of noise when I turn the air on? Any idea on what it could be. Sounds like a bearing or something has gone inside the compressor. If that is the case - it sounds like it would have to go to an A/C shop to fix. Any ideas? Thanks

[rocketraider]

If it was the bearing, you'd hear the noise constantly whether the compressor clutch was engaged or not. It could be the clutch coil itself, but my money says yer compressor is shot. Replacing it is a straightforward job, but you have to be certified to handle refrigerants if there's any R12 in it. I have no idea what the stuff is selling for this year.

You might want to consider a R134a retrofit if you have to replace the compressor, and if you plan to keep and use this car. That won't be cheap either, but R134a is available OTC and once the job is done you no longer have to worry about finding R12 and paying an exorbitant (90%+ taxes) price for it.

I still say all this ozone hole BS about R12 came about because DuPont's Freon patents were about to expire and they were going to lose the royalties. You wanna talk about a hazardous refrigerant, let's go after anhydrous ammonia.

[NTX5467]

From my experience, when the A-6 compressors have some "miles" on them and start making a rattling noise when they are running, it could just be that it needs a full charge of R-12 and nothing more. I agree that if it was a bearing, it would be constant as the bearing is pressed into the pulley that runs at belt speed, unless it's one of the bearings on the compressor's "guts".

Much easier to replace the compressor with a quality reman unit (cost wise) than to repair what you have, unless there's a decal or other "something" specific to your vehicle that you would desire to keep for originality concerns. You can buy the reman compressor for less than putting the bearing/clutch assembly on an existing compressor. Your judgment call on that one.

If you take the orifice tube out for inspection and find it full of metal, you'll need to get the shop to get any residual metal out of the system by flushing or replacement and/or installing an in-line filter in the system that can be changed when it gets clogged up. Such a filter would alter the originality of the situation, but is a GM recommended situation when a compressor "trashes".

As mentioned, if you have to start replacing the compressor, it would be a good idea to consider changing over to R134A from R12. Not to mention changing the accumulator/receiver/drier at the same time. R134A takes about 20% less gas than R12 does. There's also a "variable orifice tube", that you can buy from NAPA and others, that helps with the R134A situation as it seems to act like the old "suction throttling valve" in the non-orifice tube systems.

Investigate what your options are, but if all it needs is a pound or two of R12, that might be the least expensive option.

Enjoy!
NTX5467