Automotive Air Conditioning Information Forum (Archives)

rowjr1 on Mon October 06, 2014 7:23 PM

Year: 1996
Make: Ford
Model: F250
Engine Size: 7.3 Lite
Refrigerant Type: 134A
Ambient Temp: 90
Pressure Low: 43
Pressure High: 230
Country of Origin: United States

Replaced compressor, evaporator core, condenser and accumulator. I installed a red orifice tube (It looks like the one the old orifice tube was white....gonna try to get it out and see). I charged with 7 ounces of oil distributed amongst the parts, pulled the system down for 90 minutes and let it set over night with no loss of vacuum. Charged with 38 ounces of R134 (from label on vehicle). Vent temp shows 62 degrees at high idle (1250). Fan clutch is working..... 62 degrees on highway at 65 MPH. If I set fan on lowest setting temp will drop to 58 from center vent. I added two ounces of 134... pressures dropped slightly but temp stayed the same. Do I need to change to a different orifice tube or is this possibly a charge issue?

Jag987 on Tue October 07, 2014 12:48 AM

Pressures look ok, don't go adding more refrigerant yet. Check the inlet and outlet temps on the evaporator, I would suspect they are colder then vent temp and you are having a reheating issues. A blend door or heater valve may not be working properly.

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I bought a can of 134a at w**-mart that had a stop leak, oil, and dye in it. It also had a hose and a gauge, so now I'm an AC pro!

mk378 on Tue October 07, 2014 9:39 AM

I think the red tube is a lot different from a white one. There is a table of the actual sizes somewhere.

Dougflas on Tue October 07, 2014 3:54 PM

http://www.aircondition.com/tech/questions/23/Orifice-Tube-Color-Chart