2nd Gen Non-Engine/Transmission AC pressures

[DSeamans]

My AC is crapping out. It was low on R134. I put some in and the most I get on the high side is 85lbs. I thought normal high was around 200. It appears the high port is after the orifice - doesn't that drop the pressure? It doesn't matter what the low is (from 30 to 42) I never got over 85. Could it be a plugged orifice or am I buying another compressor and drier?



Thanks for the help,

Dave

 

[LRutigliano]

You didn't say how much R-134a you put into the system, but the high side being at 85psig is either low refrigerant level or a bad compressor.



Low side at 30 to 42 psig means you are probably in the 85 - 90deg F ambient right now. High side should be at least 200 psig, but more likely at 250 to 350 psig.



If you lost all of your refrigerant, chances are you lost alot of oil too and the compressor could be bad. Be sure to add approx 2oz of PAG (medium 100 viscosity) oil while adding refrigerant. Total oil capacity is approx 6 oz.



I've seen compressors with only 1 bad piston (out of 7 total) that pump but don't build up high pressures like you described. Failure was lack of lube due to total refrigerant loss.



Good luck, let me know what you find out.



Regards,

Louis

 

[DSeamans]

Ac

It was low enough that the low limit was kicking the compressor on and off. I started just watching the low side and putting in a can of 2oz pag/ leak detector and stop/ 12 oz134. The compressor stayed on, but no cold air. That had the low at 36-38 with ambient around 80*. I then hooked up the full manifold and experimented with another can of r134. Low side went up, but high didn't change. I ordered a compressor which doesnt make me to happy as it had a new (not reman) put in two summers ago. Of course drier was replaced also. I guess I get to do it again!