Ac recharge issue

[Ekays]

Hi, I have 1995 k2500. It's been r134a swapped and the ac hasn't worked for me since I bought it. Recently got some r134a and was attempting to recharge it when something weird happened. Instead of the freon balancing to normal pressures on the high and low sides, it just went up to 70 psi (too high) on the low side and stayed at vacuum on the high side. I tried jumping the compressor with no change. It engages but the pressure stays the same. I recharged it through the low side per usual.

Any thoughts? Thanks

 

[someotherguy]

Your 1995 was R134a from factory; 1994 was first year for it on GMT400's.

Low side pressure higher than normal while high side pressure is low, usually something bad bad like the compressor itself.

Richard

 

[Ekays]

Ah... that's bad news. Interesting that 95 was r134a, I thought it started with the vortecs in 96. The more you know

 

[Schurkey]

Instead of the freon balancing to normal pressures on the high and low sides, it just went up to 70 psi (too high) on the low side and stayed at vacuum on the high side.

If pressure "won't equalize" between high and low side:
1. Your gauge set isn't pushing the Schrader valve open, so the high-side gauge isn't responding, or

2. Much less likely...orifice tube plugged and there's no flow through the compressor. REALLY, really unlikely.

70 psi is not "too high" on the low side, depending on temperature and compressor operation.