Thinking about restoring AC system

[Rodericb]

When I bought my e34 2 years ago, the AC compressor was completely locked and the belt had been removed from the pulley. I was thinking about getting a new paint job but with the heat in South Louisiana already setting records in mid April (91 Degress today), I'm thinking that the money would be better used on repairing the AC system. My question is how much would I be looking at to get the system back up and running? What parts would I have to buy new and what parts could I get used? Just looking for some opinions. TIA.

[Evan]

You can buy a used compressor for $50. Then you'll need belts and Freon... if you do the work yourself it should cost you $100 - $200.

Look in classifieds for complete used AC systems. I think Jon K has all the parts you need...

[Blitzkrieg Bob]

Then you'll need to at least flush the system to get out any debrie from the failed compressor before putting any new or used parts on.

Check the system if there is dstill refrigerant under pressure, if so. then you're in luck...the compressor may be the only suspect part.

If you go with a used compressor, you'll still need a new drier and lots of O rings.

Good luck

[we_call_him_doher]

And don't forget about the cost of freon. My '90 uses R12 and yours probably will too. Here in texas it costs $40 a pound and I believe the system needs either 4 or 5 pounds so $160-200 total. Yikes..

[SharkmanBMW]

I had to replace almost all of mine, it kept leaking after each repair.
Cost me a ton, but it is still working today.
I was afraid it would only be a temp repair but so far so good!

Lots of labour to fix, parts costs are not a big deal.

[joshua43214]

I highly advise a new reciever dryer and all o-rings. If you get a reman compressor, it should be R134a compliant. the hoses may not be able to contain the r134a though and it may leak right through micro perforation inthe hose walls, but it may do that with r12 as well. The system will not cool as well in very hot weather when the car is not moving with r134a, but the new stuff is far cheaper than the old, so many people just live with it. I converted my 88 900t to r134a and it gets plenty cold as long as I am moving, and is livable when stoped, which is fine for a black car in Ohio.

I recomend letting a professional who understands AC well add the r134a so you will get maximum benifit, conversions can be picky about the proper amount of refrigerant.

[Rodericb]

Thanks for the input guys. I have a hookup on parts plus a few of my e28 friends could probably help me out with installing the parts. Nothing like a couple of cases of beer for some free wrenching. In any case, I was thinking about using Freeze 12 instead of r12 or doing the conversion. I've used it with success in my e28. What do you guys think about freeze 12? Is anyone here using it?

[Blitzkrieg Bob]

r134

[Kalevera]

It seems to be getting around that time of year again.

Read this article:

http://www.koalamotorsport.com/article-airconditioning.asp


Now, in my mind, the critical question is -- does the system still hold pressure (is it currently holding anything)? If it *isn't*, expect to replace everything. Repressurizing an old system seems to result in a chain reaction of failures -- one thing gets fixed, nex thing breaks -- 2 or 3 grand out the window right there.

If it is holding pressure, as others have said, find the faulty part(s) and replace them. You want to convert it to R134, not worth wasting time on R12. Be sure you've got an R134a compatible compressor as a replacement. You'll also need R134 valves, commonly available in various kits. I wouldn't worry about the other seals that may be included in that kit -- only replace the ones that are affected in repairing the system. R134 doesn't seem to blow out R12 seals.

Replace the receiver/drier. If the car still has the original unit, you'll need to replace the unit's pressure switch and harness with the later style (part is around $100). The original unit is NLA.


best, whit

[Alexlind123]

R12 is actually better than R134. You might notice the difference in louisiana.