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Earlier this year the AC was not working on my '93 945t. I jumpered the pressostat on the accumulator and the compressor engaged - ran for about 1 minute. I bought a can of R134a, hooked it up to some gauges and shot the refrigerant in the low side port (accumulator). The condensor started hissing at the lower, pressostat corner.
Independent shop replaced suction and high pressure hoses and the condensor - all OEM Volvo - About $900 in parts and $300 in labor. They did not replace the accumulator (replaced by PO in 2002) because it the part they bought for the task apparently didn't thread up to the hoses (makes no sense).
$1,200 later I have so-so performance on the highway and nothing at low speeds. When I roll up to a stoplight, for example, I can here the system hiss and then what cold air I did have disappears.
I'm going to do some investigation this weekend (check the pressure with gauges, run water across the condensor, ?) and see if I can diagnose the problem. The electric fan will kick on after about 30 seconds of compressor engagement, but I've read that cold water across the condenser should rule out or confirm inadequate heat rejection from the condenser. Gauges should diagnose the compressor operation.
Here are my questions:
-Do I have a high side port somewhere? Maybe on the back side of the compressor (small aluminum hex nut - looks like a port cover?). If there isn't a high side, how can you diagnose the compressor?
-I'm concerned that my compressor may be weak. What should my high and low pressures be at idle? FAQ cites 30-40 psi at idle (or should it be at 2,000 rpm?) I haven't found a high side number.
-Shop says they pushed 1.9lbs or 2.2lbs. Either would be close, neither is exactly equal to the 950g (about 2.1lbs) I found in the FAQ.
-Does anyone know if the new hoses come complete with an orifice valve? I'm not sure, but the previous owner (Florida) may have had a variable installed, because the AC worked well last year.
Sorry for the lengthy post, but I rarely have work completed at a shop and I'm pretty disappointed with my results so far. Before I go back and have them say "-it's your compressor" I'd like to dig around myself.
Any assistance is appreciated.
Andrew
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Proud to be in 313
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