Automotive Air Conditioning Information Forum

Thanks for the link I went ahead and put a new evaporator in So the only thing I need to flush is the lines. I am going to use brake clean.

PRV rarely resets to original spec and should be replaced due to aluminum fines stuck in the pop off seat.
hotrodac

I've flushed new compressor myself.

About 15 years ago I bought a compressor from the board sponsor, for my '88 Mazda truck. It arrived with oil, but a PAG oil (I could determine that readily from a drop of oil in 5 minutes using the infrared spectrophotometer). Since I was still using R-12, I had to flush, and I flushed three times with R-12 type mineral oil and dumped, then added the correct amount. Two months later, my co-worker bought a compressor from the board sponsor for his 1990 Mazda Protege, and that one arrived with R-12 mineral oil.

azlincoln79 wrote:Thanks for the link I went ahead and put a new evaporator in So the only thing I need to flush is the lines. I am going to use brake clean.

Please don't! Well at least don't blame the compressor when it fails on you. IMO

ice-n-tropics wrote:Probably oil and refrigerant release onto exhaust manifold from PRV pressure relief valva due to overcharge of oil and/or refrigerant.
hotrodac

Yes, indeed...I think ice-n-tropics nailed it.

Taking the other recommendations into account, you'll need to start over with the system completely empty of oil and refrigerant, then re-charge both to spec. If the new compressor will take 6 ounces of oil, then distribute the rest of it to the new condenser, the new evaporator, and the new receiver/dryer--1-1/4, 1-1/4, and 1/2 ounces respectively. Then, evacuate the system well and weigh-in exactly 40 ounces of R-134a. The small cans often contain more or less than 12 ounces (in this instance, probably more) since the PRV released refrigerant and oil all over the place due to excessive pressure on the high side.

JohnHere wrote:

ice-n-tropics wrote:Probably oil and refrigerant release onto exhaust manifold from PRV pressure relief valva due to overcharge of oil and/or refrigerant.
hotrodac

Yes, indeed...I think ice-n-tropics nailed it.

Taking the other recommendations into account, you'll need to start over with the system completely empty of oil and refrigerant, then re-charge both to spec. If the new compressor will take 6 ounces of oil, then distribute the rest of it to the new condenser, the new evaporator, and the new receiver/dryer--1-1/4, 1-1/4, and 1/2 ounces respectively. Then, evacuate the system well and weigh-in exactly 40 ounces of R-134a. The small cans often contain more or less than 12 ounces (in this instance, probably more) since the PRV released refrigerant and oil all over the place due to excessive pressure on the high side.

Correction: ...weigh-in exactly 42 ounces of R-134a.