Pag oil in compressor for startup of new crate motor

[chevyshawn]

I'm working on a new Chevrolet zz6 crate motor that is pretty close to firing up. The car has a new Vintage Air Heritage series unit with an ac delco 4849 pancake style compressor. All ac lines are installed. The schrader valves in the high and low side are located in the Vintage Air fittings that attach to the compressor. I'm planning on adding pag oil into the compressor through the schrader valve ports with the schrader valves removed, about 1.5 ounces on the high side and 1.5 ounces on the low side for startup of the motor. I'm not charging the system yet, just adding the oil for compressor lubrication. My question is do I need to vacuum the pag oil in or can I just add it through a small tube through the schrader valve ports while spinning the compressor by hand? Does anyone see a problem doing it this way, or any ideas of a better way. Thanks.

[sccacuda]

If the compressor is new, it usually has oil in it. If the entire system is new, drain the compressor (paint mixing cup works great) to see how much is in it (turn the compressor clutch to help dump it). Then just add back whatever the system requires. No need to add through the schrader valves, in the compressor is fine. Once everything is buttoned back up, and right before you plan to charge, turn the compressor clutch by hand a few times. This will push the oil out of the compressor.

Adding extra oil to a system that already has oil will affect your cooling, so only put in what the system calls for.

[chevyshawn]

Thanks for the reply. After I put the oil in the compressor, will it hurt anything in the compressor to fire the motor up without the system being charged. Seems like the oil would get pushed out and there wouldn't be much lubrication?

[sccacuda]

Thanks for the reply. After I put the oil in the compressor, will it hurt anything in the compressor to fire the motor up without the system being charged. Seems like the oil would get pushed out and there wouldn't be much lubrication?

If the system isn't charged and the pressure switch is installed and wired correctly, the compressor clutch won't engage; compressor will not turn. The clutch freewheels separate from the compressor. If your worried about it, just unplug the clutch until your ready to charge the system with freon.

[dontlifttoshift]

Craig is right for most applications but the R4 compressor with the GM serpentine systems DO NOT have oil in them.

[dhutton]

Craig is right for most applications but the R4 compressor with the GM serpentine systems DO NOT have oil in them.

Good to know! Thanks.

Don