RE: 5000S Air Conditioning System Problems

[enzeder@ix.netcom.com]

FWIW, the receiver/dryer on my '86 4ks has a little plug that blows over a certain pressure.  I think it's painted over because I don't think I ever saw 
it until it popped.  Don't know what the pressure is, but my advice is to double check which way you all hook up AC lines.  Luckily, the replacement was 
only about $20 (from Audi no less).  BTW, you can overcharge an AC system, there has to be room for expansion.  So far my AC has over 200k miles and is 
going strong, well, it still works;-)  The AC on my car cycles too, as it should.

Arryn.



On 10/23/97 14:43:12 you wrote:
>
>I'm not an AC specialist nor have I BTDT, just thinking loud...
>I guess enough pressure buildup could cause the compressor to stop
>spinning and, in order, the clutch could burn. But such pressure would
>probably blow a line first, and keep in mind that there's a safety
>pressure switch that disengages the compressor in case of high pressure
>in the system. A restriction in the circuit causing such enormous
>pressure buildup would prevent the system from normal operation even if
>the freon level was low. And you say the AC worked right after putting
>the new compressor in. I doubt if the copressor cycling is a symptom of
>low freon pressure. It is supposed to switch on and off to keep the
>evaporator temperature at constant level. My compressor switches on and
>off quite frequently, yet the AC works very good. I suggest that you let
>a competent AC shop check and maybe partially disassemble the system to
>look for a possible restriction (I doubt if it exists, though). A faulty
>control unit could cause it only if both evaporator thermostat and high
>pressure safety switch failed. To protect the new compressor I would
>suggest that you adjust the compressor drivebelt a little loose. This
>way the belt would rather slip than cause the clutch to fry.
>
>Aleksander Mierzwa