Help Please! Vac Oil In New AC System

[Davo in Australia]

I just put together a brand-new AC in a car and was pulling a vacuum when I was distracted by the kids running around. What a big mistake. I didn't turn off the valves before I turned off the vacuum pump and by the time I noticed the oil level in the pump had dropped and there was oil in the gauge manifold sight glass and in the blue and red hoses.

Searching around the Internet makes it sound like the entire system has to be cleaned, compressor out and drained, the whole bit. What have I done?????

[Yallrun]

I'd start pulling a vacuum again, see if you can pull what ever may have got in. At this point it can't hurt.

[Davo in Australia]

Thanks for replying. I think I'll do that, but it sounds like I'll have to take my lovely new system apart and clean it with some sort of a solvent. Talk about learning the hard way . . .

[Yallrun]

I'm right there with you buddy. I put a new compressor in my Tahoe and failed to see the label that it had 8oz of pag46 in it for storage and shipping purposes. I thought it was pag150 and ran freon and 3oz more of pag150. Once I realized the label said pag 46 and compressor had a slight surge, I knew a flush had to be done. Then start over.

[Davo in Australia]

That's a tragic story! It just goes to show how careful you have to be and how you can't let yourself be distracted.

[wptski]

Another thing. If after you pull the vacuum, close the manifold valves, decide you need to run your vacuum pump again, be sure to start it first and run it for a while or you'll suck the oil from the vacuum pump that way.

[Davo in Australia]

Thanks for that. That makes sense, so the pump has enough vacuum to overcome the vacuum in the aircon system. Hopefully I've learned my lesson this time.

[bohica2xo]

Not that big of a mess to clean up. A lot depends on the location of the high & low side fittings.

Side can tap & a couple of cans of brake cleaner. Dry compressed air.

Pull the compressor & flush it with fresh oil.

If this is a CCOT system, and the low side hose was connected to the accumulator - just replace the accumulator.

Vacuum pumps can run for hours without an issue. Don't be in a hurry to shut one off. In fact, it is good for it to run long enough to get warm - this drives the moisture from the vacuum pump oil. Changing your pump oil is also a good thing - just not by sucking it in to your system...

[Davo in Australia]

Sorry, I should have mentioned by now that I pulled some bits off today and the oil is only in two hoses, with no sign of it in anything else. I was lucky - the charge ports are very low and so the oil only seems to have gone into the hoses and stayed there, thanks to gravity. The plan is to clean the hoses with methylated spirits, (denatured alcohol for you guys), and then finish with compressed air. (I'll have to see if I can find some brake cleaner in this little town.) Of course the brand-new drier has to be replaced, too, but I should be able to get one.

My gauge set is full of oil but at least it's not actually attached to the car and so should be pretty easy to clean.

[wptski]

Thanks for that. That makes sense, so the pump has enough vacuum to overcome the vacuum in the aircon system. Hopefully I've learned my lesson this time.

Some vacuum pumps are listed as having a check valve to prevent this in case the power is pulled(no different than switching it off), my JB is supposed to have this feature but it seems that it doesn't work!