How to properly drain a compressor?

Friendly format provided to inquire about automotive a/c systems.
Archived Forum

Moderators: bohica2xo, Tim, Dougflas, HECAT

Posts: 18
Joined: Sun May 14, 2017 6:47 pm

How to properly drain a compressor?

Postby AGrayson84 » Fri Jun 16, 2017 2:21 pm

Hi everyone, I have a compressor that is only a few months old, but I decided to tear down the entire A/C system and start from scratch with filling the PAG oil and refrigerant (I feel there's a chance I added a little more than the required 14 oz when filling the new compressor late last year when I installed it and other new components after flushing the lines. A/C hasn't been getting cold enough, long story....). Other than letting the compressor gravity drain in an oil pan, is there anything else I can do to ensure I get all residual oil out of the compressor? I know you're not supposed to flush it with A/C flush chemicals. Should I perhaps hood the lines that bolt directly to it and try to blow out more oil with dry air?? If so, does it matter which side I attach my air nozzle to?

Also, when filling the compressor, does it matter if I fill via the low pressure line or the high pressure line, if the lines attached directly to the compressor are disconnected from everything else when filling it? Thanks a bunch!!
Posts: 209
Joined: Mon Apr 18, 2016 6:10 pm

Re: How to properly drain a compressor?

Postby Dougflas » Fri Jun 16, 2017 4:15 pm

Invert it to drain and also rotate the clutch hub. Pour new oil into the suction port and rotates it.
Posts: 1
Joined: Fri Jun 16, 2017 5:10 pm

Re: How to properly drain a compressor?

Postby CableGuy73 » Fri Jun 16, 2017 5:20 pm

Hello everyone I have a similar problem with the installation of my new AC system on a Chevy Silverado 2004. After I installed all the in components and added pag oil and refrigerant I continued to test the AC unit by my truck around the block a few times while running the AC. It ran great got cold quick when I drove up into my driveway and turned off the engine it leaked out about to ounces of pawg oil period I'm not sure where it came from can anyone help? Also let me add that I did vacuum out the refrigerant put the vacuum back on the system to check for leaks and it is still holding vacuum i assum have no leaks.
User avatar
Posts: 315
Joined: Sun Apr 24, 2016 6:29 am

Re: How to properly drain a compressor?

Postby Cusser » Sat Jun 17, 2017 6:18 am

Two ounces is a lot of leakage !!

Maybe you just spilled some when you added to the system, if you added after the compressor was bolted on???

Obviously, you confused more here than just me.
Posts: 3
Joined: Fri Jun 23, 2017 9:57 am

Re: How to properly drain a compressor?

Postby anderson0220 » Fri Jun 23, 2017 10:12 am

My technique is a little bit strange but it works. I use hair blow dryer :D My wife is so upset when I used her personal hair dryer lol.

Return to “Automotive Air Conditioning Forum”