I need to replace the compressor on my 1985 4000S quattro, it knocks/bangs when running. Can anyone suggest a good source for compressor. Does anyone make conversion kit to go from piston to rotary compressor. Griffiths quoted $499 and that was more than I wanted to spend. I've got plently of R12 so I do not need to convert the freon.

Peter

 

Do you have the facility to do add R12 without leaking? You could get into serious trouble (federal offense) if you leak that stuff into the atmosphere. For the parts, try here:
autohausaz

 

Sterns,

If I am not mistaken, the air coditioning compressor used is an AC-Delco R4, I think is the nomenclature.

It is not an Audi design, just an off the shelf component, bolted to an Audi designed mounting plate.

Straight changeover.

Cheers,

George

 

I think York made the compressors, probably one of the biggest AC parts manufacturer. The clutch you can sometimes get on your own. Check out RockAuto.com! On the 4000 models I have seen both rotary vane and piston type compressors used. If you go to a junkyard you can probably get all the parts that you need, mostly compressor and mounting brackets. You can change from R12 to R134A by changing O-rings and the hoses. The R134A has smaller molecular structure and eventually will bleed through the older hoses. The problem with R134 is that it doesn’t have the same cooling capacity as the older R12.

 

Kinda ontopic here lets see if you guys know cant hurt.

I have a problem. I just noticed that my A/C clutch has a wire connected to it. Well duh it would rite?

Anyway it splits off 2 ways and then one goes into a tube then through the bumper I guess. And the other goes to a plug that has a rubber boot on it. I cannot for the life of me figure out where this 2 wire plug goes. Its about foot and half long wire with a rubber boot on the end it forks off from the clutch wire. If you have a 1984ish Audi 4000S Quattro please I really would like to know where this plugs in I dont like having dangle wires

Thanks guys.

 

The Audi 4000S AC system is rather simple. Typically the clutch will be connected in series with an over-pressure switch as well as an under-pressure switch. I suspect that this "2 wire plug" is from one of these switches, that is if your system is not working. Otherwise it could a leftover for optional equipment, other markes or even some sort of a diagnostic port.

 

its not working properly and I dont know where it plugs in and I cant figure it out :/ thats my problem I wish I knew where it went.

 

If one of the two mentioned switches is disconnected, the clutch won't engage the compressor.