It's May in Tucson, and my AC is on the fritz.
My 92 Accord Wagon has an apparent AC leak. AC worked in Feb, when I
bought the car, and when I exercised it (but didn't really need it)
during the winter and spring. Now that it's 100f, there is no coolant
pressure at the filling valve and, unsurprisingly, no cool air. I've
got a leak and am looking for a schematic or service manual for the AC
system. My Clymer is worthless. Do any of the aftermarket manuals
cover the AC system in any depth? If not, where can I find the info?
Google isn't sniffing out what I need.
I've fed the system a small can of 134 based coolant and oil, with UV
dye. This gets me slightly cool air, but does not reveal any leakage.
I haven't run the system for more than a few minutes for fear the
mongrell coolant load will damage something.
The previous owner had just installed a new compressor before selling.
There is no sign of dye on or near the compressor, or fittings.
I'd like a fairly comprehensive AC guide, so I can take out various
sections for cleaning/testing/replacement.
Leaks occur in two common places: round the hose O-rings and through pin
hole corrosion in alloy parts.
Less commonly it leaks through the wall of old R12-type hoses.
Your 92 was built for R12 refrigerant When the compressor was replaced, the
system may have been updated to R1134a, which requires new O-rings. If this
was done, there should be an update sticker somewhere, typically on the
inside of the hood.
Locate the high pressure valve on the tube that comes from the condensor in
front of the radiator. Press this for a moment. If you get a loud, sharp
SHHH sound, the pressure is OK. If you get a quiet, soft shhh, you still
have residual pressure, and you can top up the system with Duracool or
similar compatible refrigerant for about $20
If you have no residual pressure, then you need to take the car to an A/C
shop because you can't do this yourself unless you have the right
(expensive) equipment. Have them do the following.
a) replace all O-rings with R1134a compatibles.
b) if the system was still R12, pull the compressor off, replace the oil and
fit the necessary R1134a fittings, and replace the drier cannister.
c) evacuate the system (this is what you can't do yourself) to test for
leaks. If the hoses themselves are leaking, you will have to get new hoses.
d) refill with R1134a.
Get a quote from several shops. It should be in the $200 or so plus parts
range. No shop can tell the hoses are bad without running tests.
It was still fitted with the R12 valve with no 134 sticker in sight.
Got a pressure guage. It drops daily, so I seem to have a very real
leak to find and fix.
Heh. That $200 thingy is what I was hoping to reduce!
I know I can't properly evacuate, test, and recharge the system. I do
plan to go over the whole system, chasing the coolant leak and replacing
any tired parts, seals, o-rings, etc. as I go.
Thanks for the info!
I'll have a service center test, purge and refill it when I'm done.
FWIW, I ran the system for a few more minutes and I found a leak; it's
at the front of the condenser - about as easy as possible to access and
fix. Also, one of Tegger's links led me to Autozone and some good
diagrams and and instructions - all I really needed. With any luck,
I'll be in cold air tomorrow! :)
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