I just had a guy help me recharge my AC on my 87 Cutlass. I bought a drier, oriface tube, a flush kit, R134a and an 8 oz bottle of pag oil. I changed all of the orings. We drained all of the oil, flushed and blew air through the system. The guy helping me, poured the oil into the back of the compressor then bolted everything up. Vacuumed the system. Charged the system with 3 cans of Freon. The system with r12 was supposed to use 48oz. I read where R134a should be charged at about 80% of what r12 uses. So 36oz should be close, if anything just shy of 80%. The system before, worked, just did not cool below mid 60's. It now cools very well. Shortly after the recharge I started hearing noise, I could see where the belt, on the down side, was bouncing so I thought the noise was belt noise. I tried tightening the belt, noise is still ther, sounds like the compressor is knocking.... still blowing cold. Would a can of oil charge help?

 

I've had this same problem on my wife's 85 D88 and frankly don't have an answer. The R4 that came on the car was a rebuilt unit that knocked when engaged. I finally got tired of this and replaced it with a Four Seasons rebuilt from RockAuto. It worked great for the first year, but now is knocking just like the last one. Of course, you'd think that by now I'd have learned NOT to waste money on cheap rebuilt units...

I may just pitch the whole thing and convert to a Sanden. I have a Sanden (and Olds-specific bracketry) on the way to use in my 67 Delta and depending on how that goes, I may get another one.

 

I know the sanden compressor is more efficient and likely more suitable to R134a. I also know this would entail new hoses, etc. where did you find Olds specific brackets?

 

Classic Auto Air. Mine are on the way and should be here next week.

 

I went to their website and did not see Olds fitment, did you request special assistance?

 

Every so often you have to actually dial the phone and speak to a human.

I was fortunate to connect with Mike Oliveras, who is also a member here. He owns a 68 Delta that has served to prototype some of the Olds-specific parts. You can reach him at:

813-251-2356 ext 7029
MikeO@classicautoair.com

Here is a photo of a customer's Cutlass with the Sanden setup.

 

Very common problem with R4 compressors, my old boss would go through his junk yard till he found on that didn't knock. I have had them seize but you might get a couple of years out of it.