2nd Gen Non-Engine/Transmission A/c

[Don Bellamy]

How is it that the a/c system can have pressure but not a trace of 34 and the truck has been setting a week?

Don

 

[B.G. Smith]

Pressure where? You mean R134 huh, and how do you know there is not a trace? I really don't understand the problem/question. bg

 

[Don Bellamy]

Pressure where, in the ac system huh, my truck stopped cooling late summer 08, the truck has been setting a week now, I disconnected a line and there was pressure? I know the system was out of 134 and if I had a leak and the truck has sat idle why would there be pressure, would all pressure had leaked off?

 

[B.G. Smith]

If it is the compressor seal or even a slw leak, somtimes there will still be some vapors left after a while. the clutch on AC will stop engaging at 23#. Sinnce you opened a lineit probably needs to be evacuated now but I would add some refrigerant and try to locate the leak before going into the evaporator change out. Sorry for the mis-understanding. bg

 

[Don Bellamy]

My thought was if the 134 has all leaked out why would there be any pressure at all? My leak is in the front of the compressor, I replaced the evaporator last year.

 

[B.G. Smith]

It's been 100 deg. or there about here lately. At 100 deg. R-134 pressure in a sealed system would be 124. 3 pounds per square inch. As the container temperature falls the pressure would fall or if the temperatur rose the pressure would rise. At 140 deg. the pressure would be 229. 4 psig and at 70 deg. it would be 71. 2 psig. as long as there enough liquid R-134 inthe sysem to completely fill the system with vapor. As the R-134 leaks out the liquid at some point would all be gone but you would still have vapor pressure and it drop slowly depending on how bad the leak is. In your case, evidently the vapor was still leaking out. Of course the only way to know if pressure is still present in the system regardless of how long it has been out of service is to connect the proper gauges to the system. Bet this is as clear as mud. bg