90q A/C compressor hose leaks

[Andrei Kogan <abk@phy.duke.edu>]

Hello everone,

My A/C died the next day I replaced the timing belt. The electrical part
seemed working fine, that is, the clutch would kick in and out, but the
cycling was very frequent (1 sec on and 5 sec off) and there was zero
cooling at the vents. I had it checked and the diagnosis is a leak in the
hose that attaches to the compressor. My guess is that it was working
marginally and when the compressor was moved it finally cracked open. I am
going to replace both hoses and have a couple of questions:

1. The guy who looked at it got me confused. he told me, it was the hose
that goes to the condenser, and it was on the low pressure side of the
compressor. Isn't the condenser located on the high pressure side? My
understanding of the the AC cooling is that the compressor lowers the
pressure in the evaporator which causes  the liquid agent to
evaporate/absorb heat, then compresses the hell out of the vapors  which
causes them  to condense and release heat some place else. At least this is
how the helium-4 cryostat operates in my lab :-) 

2. Just realised that there could be a different cooling principle used
--Joule-Thompson effect. In this case, the cooling would  be generated by
forcing the agent through a flow restriction rather than by evaporating the
liquid. It would still mean that the "condenser" , that is, the place were
the heat is released, is on the high pressure side.  Could someone tell me
which design is used, or is there some other principle involved that I am
not aware of? 

3. Are the compressor  hoses hard to replace? If they aren't too expensive,
I would probably just do both of them. What should I watch out for --- any
tricks when attaching them, or dealing with the a/c system in general. Is
there a diy procedure for checking if the system is OK for recharging?

4. Is the a/c system on the 90q similar/identical to 1984-87 5 cyl audis
(4kq/cgt)? Then I could use  guidance from my Bentley (1984-87 4k)  

Many thanks, this car keeps me entertained but I feel that there is some
light emerging at the end of the tunnel.



Andrei