[V8] Air Conditioning Q's

[Scott Phillips]

Craig.. That's what I was looking for, there are valves under the
switches so they can be swapped out without losing the charge should
they need to be replaced,. But while I'm there I should as lease replace
the valve ;-)

 

Scott

 

From: NicolCS at aol.com [mailto:NicolCS at aol.com] 
Sent: Wednesday, March 28, 2007 10:17 AM
To: Scott Phillips; V8 at audifans.com
Subject: Re: [V8] Air Conditioning Q's

 

Why are you worrying about the switches?  Check the HP switch for
continuity. Continuity=probably fine. While the system is empty, check
under HP and LP switches; if there's a schrader valve under switch (and
that's likely) you can change them after the system is charged if you
need to.   I'm pretty sure the system uses an orifice tube, the car has
an accumulator so 99% sure it has an o-tube.  If so, it should be
downsized.   Change O-rings. FLush system except compressor. Drain oil
from compressor. Prefill compressor with proper amount of E100. Change
the dryer. Evacuate and check if it will hold vacuum.  If OK, add vapor
to about 50 PSI and sniff (with detector) for leaks.  If OK, add
refrigerant until pressure prevents any more; listen for LP switch.
Rotate compressor by hand to verify no oil blocking. Start system.  If
compressor won't start, bypass LP switch to force compressor ON and
slowly meter balance of refrigerant in through low side.  Remove LP
switch bypass and check for cold at entrance to accumulator and cool at
exit. If you have cold at the accumulator, you're good to go!  IME, 90%
of the time, all that's wrong is a refrigerant leak or compressor
failure.  If you wanted to be picky, you could change the LP switch to a
134 type, but it should work with the existing LP switch, it just won't
be "optimal".  

 

Craig Nicol

90 V8Q

95 S6 avant





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