Automotive Air Conditioning Information Forum (Archives)

rojeho on Sun July 26, 2015 3:25 PM

Year: 2001
Make: Chevrolet
Model: Suburban
Engine Size: 5.3
Refrigerant Type: R134a
Country of Origin: United States

I replaced the compressor, drier, condenser and orifice tube. Vacuumed down and it held overnight. Added refrigerant and the compressor kicked on and started blowing cold air. Added 49oz by scale (called for 48oz), everything seemed to be going well. Turned on the rear AC fan and the compressor immediately shut off. I turned the rear fan off, turned the whole system off, and turned the engine off. None of these got the compressor to turn back on and cool the front again. At this point the gauges are showing equalized pressure.

Is there something in the rear system that also needs to be changed during this process? Did I just kill a new compressor? I hope there is something minor to fix this. I'm pretty dejected right now because it was going so well.

I did all of this work because the original compressor died with a squeal and then warm air. There was no metal on the orifice tube. I flushed all of the front lines but did not flush the lines to the rear.

Jag987 on Sun July 26, 2015 4:46 PM

Why was the compressor replaced? If the old one came apart and left metal or other debris in the system, then the rear lines and evaporator would need to be flushed along with replacing the rear expansion valve. Was the system flushed at all and was any oil added?

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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!

rojeho on Mon July 27, 2015 5:58 PM

I changed the compressor because the system was functioning well and blowing cold air. I stopped at a light and I got about three seconds of loud shriek and then warm air. When I put the gauges on the system there was equal pressure (70 or 80, can't remember but it wasn't a catstrophic leak that caused the sound which is what I wanted to check) across the compressor. I changed the components. The orifice tube was completely clean - no metal bits on the screen. I flushed all of the front lines and got clear fluid from the start. Because of this I didn't flush the rear. Is this my mistake? Did I kill the new compressor? Again, it was so immediate when I turned on the rear fan that it feels more like I tripped a switch or something. It wasn't two seconds after I turned on the fan that I started getting warm air from the front AC and the compressor was off.

I can't remember exactly but when I was done filling refrigerant and checking just the front AC the pressures were something like 230/60 and now after I tried to engage the rear AC it's 80/80.

mk378 on Tue July 28, 2015 8:28 AM

It could be the clutch gap. See if the clutch is getting power. If not, check the fuses, etc. its an electrical issue. There isn't anything in the refrigeration system that would cause this.