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Old 06-29-2010, 09:40 PM   #1
smorg007
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Help with stock A/C

I have read the FAQ's, read A/C 101 basics and still I need help. I have factory air. I have replaced all related switches and relays. The system was pressure check and has no leaks. Oh yeah it had been converted to R34a by PO. No matter what we do it has 0 reading on low side and 120 on high side with ambient outside temp 100. No change of pressure with rpm revs. When engine and A/C off pressure equalizes at 90 psi at both low and high side. Could this mean my Evaporation Control Valve is bad and it's not creating any restriction so all I have is freon flowing in a circle and no gas is being created.
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Old 06-29-2010, 09:55 PM   #2
crushermechanic
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Re: Help with stock A/C

it sound like it is low on gas. at 100 degrees you should be looking for about 225-250 high side and 25-35 low side. do you know how much it holds. did you charge it with scales?
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Old 06-30-2010, 09:32 AM   #3
smorg007
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Re: Help with stock A/C

I watched the mechanic put in three cans of R34a, he waited several minutes between cans. I don't know what you mean by scales. He used a normal two gauge manifold with three separate hose lines that attach to the high, low, and freon can. He turned the screw on the cutoff switch so the compressor stayed on and did no cut off. The high pressure line was its normal hot to touch but the low pressure never became cool or sweated. I hope this makes sense.
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Old 06-30-2010, 08:46 PM   #4
crushermechanic
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Re: Help with stock A/C

i dont know how much freon it should hold. he put 2 1/4 pounds in. most systems i work on hold around 4 pounds. i always use a 30 lb can and a set of scales to put the correct amount in. it could be a stuck expansion valve but they normally stick closed not open.
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