Mechanics

I AM HAVING TROUBLE WITH THE A/C

1999 Chevrolet Suburban • 122,000 miles

Before all this started, the a/c worked ok; it was just a little low on charge. When I went to charge it, the a/c cooled down great and accepted the added charge. When the gages were disconnected the service valve on the high side was leaking. So I bought a new one; reclamed the refrigerant and installed the new service valve; evacuated the system, and recharged the system. Now here comes the problem. The system will not cool. The rear air kind of works, and the front air comes out at 85F. The line from the orifice tube to the firewall/evaporator is ice cold. The line coming out of the evaporator to the accumulator is warm to the touch as well as the accumulator. These components(Accumulator and return line) usually are cool to the touch. So I went and changed out the rear expansion valve, the accumulator, and the orifice tube. The results have been the same. At 2500RPM High side 275 Low side 25. Outside temp 89F. Inside of vehicle rear air 60F; front air 85F. For some odd reason the refrigerant is not flowing through the evaporator. I have taken the fittings apart and blown compressed air through them, with all the hoses flowing freely. I did add 1.5 oz of PAG 100 for the install of the new accumulator. The manifold line assembly from the compressor is fairly new. I recently purchased the vehcile. I have worked on cars and trucks for over 20 years and have never had a problem like this one. I am not a shde tree mechanic. I went to UTI in Phoenix, AZ.
Avatar
Jpwtruck
September 6, 2011.



What are the readings at idle? 25 on low side indicates low charge. I recommend using an ac machine it's the only way to properly charge it today and results are usually very good.

Merlin2021
Sep 6, 2011.