Proper method of charging air conditioning system

[charlief1]

You're pressures are a little high but look almost normal so I'd leave it alone and just get a new low pressure switch for it. Other than that it sounds lke you've done eveyrthing right.

 

[theCATman]

Yep... the low pressure switch has shat the bed. New switch from GM dealer is about $35. I know this why you may ask, I just had my low pressure switch die on me a couple weeks ago. Perfect timing, it was only 88* with a 72* dewpoint. Good thing it wasn't hot & humid out or anything

 

[monteperformanc]

Thanks just ordered one today. Should be in tomorrow, and we'll see what happens next...

 

[Rebel]

That hydraulic connection to the accumulator has a schrader valve, you won't have to discharge the system to replace the switch. I was thinking that might be your next question.

 

[monteperformanc]

That hydraulic connection to the accumulator has a schrader valve, you won't have to discharge the system to replace the switch. I was thinking that might be your next question.

Thanks, I did know that. My concern now is really if I have too much r-12 in the system. It's almost 4 pounds, as far as I can tell, and the proper amount is 3.25 pounds.

 

[Roger]

I finally gave up. It had 3 leaks when I t
dropped $195 to have a pro finish the a/c. He said I only had one leak, don't know why he didn't find the other two, which I pointed out to him. Finding a pro who'll use R12 wasn't easy, finally checked with a Buick service manager who ownes a GN.
It's putting out 39* at the left center vent now & I keep checking it. Still don't know why the pro said it wasn't leaking.

 

[monteperformanc]

Mine is working good now with the new pressure cycling switch. I'm just worried because there is supposed to be 3.25 lb of R12 in there, and I have almost 4 lb. I'm not sure if that will cause a problem.

 

[Rich Gio]

It might, You don't want to blow the rupture disk on the compressor. I'm not saying a 12 ounce over charge will do that, but you could bleed off (recover) a bit of the charge. Usually the High pressure switch will shut the compressor down first. The only way to know for sure is to recover the whole charge and weigh it back in.