I took my car to get "charged" (1995, R134a cocktail)...They ran some tests and it passed the vacuum test...it held vacuum for 15-20min. Then was told they could not charge due to a leaking schrader valve in the high pressure line. Thanks for the flouresent green juice all over my downpipe, smells good and smokes good

So, I pay for the diagnostic test and leave...dissappointed, 1) its hot, and 2) alot of the 1995 AC parts have been discontinued.

Last night, I begin removing things to get to the culprit...and hear a hissing noise while pushing the AC lines aside. It's not coming from the "leaky" schrader valve...but a coupling nut on the LOW PRESSURE line.

hmm...I tighten, start the car, turn on AC, no hissing.

Pull the high pressure schrader valve cap, and hit the "tit" in the valve and whoooooosh.

It is my understanding this is how a schrader valve is suppose to work...just like a tire, and if its leaking, there is no way I can release pressure if I hit the "tit", because it should have already leaked out

Basically I think I don't have a failed schrader valve in the high pressure line, but HAD a loose coupling nut connection on the LOW pressure line and paid for a wonderful diagnostic test.

Is there something I'm missing?? Why would they tell me failed schrader valve? I don't want to have to have a piece custom made just yet. I don't know enough about AC systems to bring the car back and bitch. Any insight is appreciated.

 

I'm most concerned that you say A/C parts have been discontinued. (I have a '95 too.) A schrader valve is a fairly common A/C part. Couldn't they have rigged something up to fit your car? Is there a better A/C place in town that might know more, or be more creative in solving the problem? You already suspect they made an incorrect diagnosis, so maybe they're also wrong about the parts or the solution to your problem.

It also sounds like you think you've fixed the problem....so, go to a second A/C place have them evacuate the system and recharge it. Let us know how it turns out.

 

Agreed.

 

I'm not an expert on air conditioning but, can advise that the valve can be easily tested by spraying some soapy solution on it, just as you would with a tire valve.

When you pushed the valve and heard the pressure release, that indicateds that the system is still under pressure, which is good. That way you have no need to evacuate but, to simply refill. You can buy refill kits very inexpensively at any auto store and do the fill yourself. I got a cheap kit a couple of years ago and use it to charge up the system on one of my cars that has a tiny leak in it. Two bottles per year makes it happy - for now.

Albert

 

yea the soap will work. nothing special about the schrader except for the rubber in it. even uses the same tool as a tire. if there is pressure in it how the hell did they pull it to vac???

snap on even makes a cool kit that allows you to remove and replace the valve without evacuating the system

 

This is what i was thinking aswell if they vacced out the system and said they couldnt charge it then there should be no pressure in the system.
If you have found a leak else where then put a fluro gun on it to check for die at the leak.
Also if there s a leak at the valve , like the others have said soapy water will tell you.