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99 silverado ac drier frosts up

Posted: Thu May 14, 2020 5:17 pm
by ngooch2
99 silverado 5.3
Replaced compressor, drier, orifice, manifold line, condensor, flushed evaporator, pulled vacuum for couple hrs, let it sit, no leaks, installed about 2 1/2 to 3 cans of r134, cools great but after a couple of minutes the drier frosts over, any help would be appreciated

Re: 99 silverado ac drier frosts up

Posted: Thu May 14, 2020 5:30 pm
by Tim
Which thread do you want to use? Having 2 of the same post is not the best for responses.

Re: 99 silverado ac drier frosts up

Posted: Fri May 15, 2020 6:38 am
by Dougflas
Please give more info as rpm (should be 1500) Max cool. doors/windows open, low side psi, high side psi, Ambient temp, humidity, vent temps, does compressor clutch stay engaged?

Re: 99 silverado ac drier frosts up

Posted: Sat May 16, 2020 6:05 pm
by JohnHere
According to my references, the Crew Cab model takes 36 ounces of R-134a while the regular cab model takes 32 ounces. Charged directly from the small "12-ounce" cans without using the proper equipment, you won't notice that the actual amount each can holds often varies quite a bit. So I think what we have here is an incorrect charge amount.

Re: 99 silverado ac drier frosts up

Posted: Sun May 17, 2020 12:59 pm
by GM Tech
Frosty A/D is Bad? News to me. Really humid conditions shows great cooling....