BunnMan

Howdy folks,

Fired my old gal up in the garage the other day just to hear her run and keep her honest. Flipped on the AC to run the freon around and keep the seals wet. AC blew ice cold with seemingly no worries. I rapped the pedal and she let out a loud short burst and hiss under the hood, some greyish mist was visible blasting out under the left side of the hood. Rapped the pedal again, same result. Shut her down and openned the hood. Fired her up again, AC still on. This time I didn't even have to punch the pedal, she let out the same burst at idle. I got out of the car to look around with her still running. Then I saw the source. A small valve on the inside top of the AC compressor was bursting out a blast every so often, onviously freon and oil hence the mist. I noticed the AC wasn't cold anymore which was expected due to the loss of freon from the valve. Shut off the AC and no more bursts. I guess that is some sort of pressure relief valve and maybe some obstruction somewhere in the plumbing causing it to overpressure and release. I can post a picture of the valve if necessary.

If so I can't figure why the AC was still cold??? If there was a blockage then the flow would have to be effected and without circulation how was it still cooling the air off??? What could get blocked??? I only had it on for maybe a minute, certainly not long enough for anything to freeze up.

Help! My girl is sick!

-BunnMan

Tony71502

The A/C wasn't cold any more. Then a few lines down you said you can't figure out why the A/C is still cold. MAKE UP YOUR MIND!!!

I'm not an A/C expert, but if I had to bet money on it I would say the valve that you saw spraying refrigerant has gone bad. Whether that requires a new valve or a new A/C compressor I can not say. I ditched my A/C a long time ago.

BunnMan

Gotta read a lil closer Tony. I said when first turned on it was cold, blew out freon a couple times, then wasn't cold. Later I summarized by saying that if there was enough of a blockage (no flow) to cause the relief valve to blow off, it wouldn't have blown cold at first.

I was thinking bad reflief valve too, just wondering if anyone had the problem before. I'm 37 and been drivin/fixin my cars and other folks cars for a way long time and NEVER seen or heard of a A/C relief valve blow off...guess I'm just lucky

mjr46

the pressure relief valve pops when pressure in the system reaches the limit to pop the valve off........you need to put a set of gauges on the car and read high and low side pressures, don't condem a valve that may be operating as designed without knowing a/c pressures, YOU CANNOT and I repeat CANNOT work ON A/C systems and diagnosis them in such a case without gauges to read PRESSURES TO NOTE where prob exists, if one side spikes and the other side is pulled into a vaccum then there might be a blockage, orifice tube possibley but if there is a blockage, think about it...how did it happen?? often times is a result of an internal compressor failure or one about to occur, furthermore, if you have the pressures spiking on both sides, expecially on the high side then I'd look at the condensor and clutch fan if you have a bad clutch fan put a fan in front of the radiator on high and if such is the case you can watch the pressures drop on the high and low side...but the fan must push enough air....LUK