Hello folks,

I changed out the AC compressor on my daughters 1990 caravan 3.3L V6 this past weekend.
The AC has not been working in her car for several months now so when I disassembled the AC compressor from the engine there was no pressure at the Schrader valve.
The pulley on the AC compressor had the metal to metal grinding resistance.

I went and pulled another AC compressor off a 91 caravan at a pick and pull salvage yard.

My cousin(Who is a diesel mechanic) said that when I install the new one I would have to add about 1 ounce of mineral oil to the compressor before bolting the lines back on. When I bought the mineral Oil from O'Reillys auto parts store, they mentioned that I would have to add a lot more than one ounce.

How much mineral oil should I install inside that AC compressor?

Thanks,

 

First of all, are you recharging with R12 refrigerant? If you are, add about 4-5 oz of mineral oil into the compressor. You would be very wise to change the drier (and the expansion valve) and add 1 ounce of oil into the drier before you install it. If it is too hard to get oil in the drier, add another ounce to the compressor.

If you are re-charging with R134a, don't use mineral oil. Use an ester synthetic oil that will safely mix with any residual mineral oil in the system. Avoid PAG oil on an old R12 system.

 

It's going to be recharged with R-12.

Okay 4-5 ounces of oil. I got clarification on the mention of adding only one ounce is because I didn't drain the fluid from the pick-n-pull AC compressor.

Thanks for the heads up on the dryer and expansion valve, I'll start researching info on these two parts before recharging.

Appreciate your response Hoosierrun,