PRESSURE QUESTION?
Thread Starter
Racer
Joined: Jul 2001
Posts: 341
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From: macon, ga
PRESSURE QUESTION?
I have just recently had my a/c filled with r-134a and i think that they overfilled it. how do i check? if i buy a pressure gauge, what should it read when the system is properly filled? which is the High side and which is the low side? do i test it when the A/C is running or when the car is off? sorry for all the questions? thanks for the help?
Burning Brakes
Joined: Sep 2001
Posts: 1,166
Likes: 0
From: Tulsa Ok
Re: PRESSURE QUESTION? (ykp53)
Since you drive a 77 I'll assume a R4 compressor so low side valve will be on the fitting at the rear. High side on fender well requires a GM high side adapter to fit a R-12 set of gauges. Pressures should be in the ball park of 35-45 low side pulling down to about 21 where the compressor should kick off. High side is usually 2.2 to 2.3 x ambient temp. Anything over 250 on high side means you're probably overcharged. :cheers:
Oh yeah, check your pressures at idle and at 1500rpm. When the car is not running system pressures equalize.
[Modified by FeedVaal, 1:41 PM 6/21/2002]
Oh yeah, check your pressures at idle and at 1500rpm. When the car is not running system pressures equalize.
[Modified by FeedVaal, 1:41 PM 6/21/2002]
