A/C gremlin

[runningred92]

Ok so my system has been retrofitted to accept R-143-a by the previous owner and about this time every year I need to recharge the system. I bought a can of R-134-a and went to recharge it. With my truck running and a/c on high I hooked up the hose with an in-line pressure gauge to the L port and instead of being low it was at 100psi. UHOH! I left the air running on my way home and noticed that when I am moving the air blows at least 20 degrees cooler but as soon as I stop it goes back to blowing HOT. My dummy temp gauge on the dash is normally below the N and with the air running it moves almost to the N. Now I know the engine is at a good operating temp I have had it checked so as long as it stays right there I know its ok. Is my compressor not running correctly or??? I know a little about a/c systems but could use some help with this one. Could it be as simple as just removing coolant to proper operating pressure? Appreciate some help with this one.

-Andrew

 

[DUNE RCR]

Sounds like the suction side of your compressor make have a small leak which is allowing it to suck in some air. With a high pressure like that and lack of cooling that is what my best bet would be.

If I were you I would put a vacuum on the system and make sure it holds. If it holds a vacuum then you dont have a leak.

 

[runningred92]

Ok is it also possible that my compressor is going? It stays on constant but sounds a little whiny or higher pitched than it used to. And with those pieces could be blocking the orifice tube maybe causing the higher pressure thats not really that high? After all it is 20 years old it probably needs replaced but I am NOT going to start throwing parts at it. I want to eliminate all possibilities. Just asking because of the cheap retro fit conversion job.

 

[runningred92]

Bump!!!!!**** i still need help please ****bump!!!!!

 

[runningred92]

So I am still needing some help. I finally got some time today to keep troubleshooting the A/C. I know my gauges are good now so I hooked it back up just to make sure it read the same and it did. The other day when I first noticed the low pressures were really high as I started driving while the A/C was still on full blast the air started blowing cold again. So today while I had the gauge hooked up I pressed the gas and brought it to 2500 to 3000 rpm. The gauge instantly dropped to about 40psi from 100psi and started blowing cold. So with that being said I was hoping that would help point to a specific problem or at least give more of an idea of where I need to check next.

 

[runningred92]

I talked to a guy that claims to be a mechanic and he said since the pressure drops when I give it gas (does not need to be moving) the pressure drops and the air turns cold that the compressor clutch could be slipping. Could that be it? Is it possible to swap just the clutch or do I need a new compressor if that is the case. Since my compressor still seems to work when the rpm is up I would hate to replace the whole thing if I don't have to. Thanks for your help