One more problem, my A/C didnt work for a couple of years do to low refigerent. I had it serviced and it worked fine for about a month. Its still cools now but it makes a chattering noise from the compressor. My brother converted it from R-12 to 134a 2 years ago and it only worked for one day. This guy serviced it again and found a minor leak at the center of the compressor which he said is no big deal. He put in the 134a... now im not sure but I think the old R-12 is still there... is that gonna cause problems if its mixed?? I know there are bigs warning for this in the manual. Again Im not really sure if it is mixed or not. I dont think thats a problem since I told the A/C specialist the history I told you. Well anyways the chattering happens only at low RPM if you rev the motor or dirive at almost any speed it goes away. It only happens if the A/C is on. The clutch does cycle on and off as well when on. Is that normal it does cool fine but I guess it could be colder. Could this be a problem with the 2 different collant possible being in contact or low refgerant or what I am leaning to .... the clutch wearing out. If it is the clutch. Does any one know what parts I should get and replace and how much they might cost. Also any special tools? Is there any instructions on how to do this on the internet? And finally how much time am I looking at? Thanks.... Erik

 

Anybody, know about this?

 

All I can add is, I don't think it's your compressor. I have the same problem and it viberates the whole car at idle (650rpm). If I move the idle up with the pedal to just 800-900rpm it shutsup and smoothes out completely.
At the time I had the converstion done the following new parts were installed a.c. delco comp, NAPA drier, orfice, master conversion kit ( more complete), system was flushed, vacumed for 45min. charged with guages and the correct amount of oil/134 installed (system uses sligthly less 134 than r12).
It has progressivly gotten worse. It's reach the point where I have to turn off the A/C to order at a drive thru. I had planned to just let it go till she blowsup. But it's reached the point where I no longer want to drive it i.e. 87 Formula 350 TPI. auto.

 

If the system wasn not recovered, a new expansion control installed, system flushed, evacuated, re-oiled, and filled with refrigerant, something wasn't done right. Mixing the two is not acceptable, since the oils are not compatible.

If you're having cooling problems with R134A (who isn't?) you might want to look into R414B. It works VERY well in my '86 - even better than the old R-12.

 

If you're having cooling problems with R134A (who isn't?) you might want to look into R414B. It works VERY well in my '86 - even better than the old R-12. from Vader

I have a couple of questions:
1) The a/c doesn't cycle. From what I.ve read here in doing a search on it should. I realize the 134 runs at higher line pressure. There was mention of adjusting the cycling switch if it had a small screw located between the spad terminals. Is there a rule of thumb on how many turns and is it out or in.

2) Vader you mentioned r414b as a possable better sub for r12.
What is it, where do you get it, what other changes do you need to make.

I've been in the retail parts bus. awhile now (28+yrs) and have never hered of r414b. At this point I'm ready to try some thing else. We've been having our usual mild summer here in S.TEX. the heat index has been 103 to 108 the last ten days. Thanks