thefew

The A/C in my 1991 Accord Aero Deck is blowing 90 degree air. The compressor is an $80 junkyard dog I installed in April 2013 when I upgraded the A/C to R-134a. I installed a new receiver drier and replaced all the o-rings. I used Ester with UV dye when I did the upgrade, and I could not find a leak. There was some green oil (with the UV light) around the low pressure valve so I cleaned that up and ran the A/C the next day when I was doing some errands. I did not see any green oil at any of the connectors when I checked again with the UV light. I hooked up a set of gauges and tried to add some refrigerant. The high pressure side is only giving me about 135 psi at 1700 rpm, the Lowe pressure side is reading about 24 psi, and the system would not take very much refrigerant out of the can. It's a new can that reads 70 psi when the low pressure gauge is disconnected from the car. I'm thinking bad compressor. What have I missed? Thanks in advance for any responses.

holmesnmanny

Your car takes about 22oz of 134a, how much did you add ? Is the compressor engaging ? Is it staying engaged ? Is the ac light turning on ? Are the fans turning on ? Did you replace the expansion valve ?

Note: most ac problems are fixed by simply replacing the expansion valve assuming the system is otherwise working fine. ie compressor and fans engaging...no leaks...correct amount of refrigerant in the system.

A quick test when pulling a used compressor is to spin the clutch while blocking the two holes and seeing if it pulls suction. No suction = compressor is no good

thefew

I have not replaced the expansion valve. On my car the expansion valve is co-located with the condenser under the dash, and is probable fairly easy to replace. The system would not take the additional R-134a when I tried to charge it. I've got an almost full can hanging off the gauges I borrowed. The compressor engages and stays engaged. The A/C light on the dashboard comes on. The fans work fine (not sure if you meant blower fan or evaporator fan, but they both work.) Will a bad expansion valve cause my high side pressure to go no higher than 135 psi? Thanks.

holmesnmanny

the condensor normally sits in the front of the car...in fact i've never heard of it not since the air helps to cool the condensor...you're probably talking about the evaporator.

I'm not sure about your question to be honest but if everything appears to otherwise be working fine I would suspect either the expansion valve or the compressor. When you have the system evacuated I would test the compressor like I suggested and replace the expansion valve along with the receiver/drier.

thefew

Since winter is coming this just became a project for the spring. I will evacuate the system; flush the lines, condenser, and evaporator; replace the expansion valve and receiver drier; and test the compressor. If I have to replace the compressor so be it... Thanks for your help.