I've got a dilemma that I need some help with. I just rebuilt my Curtis air compressor but Im getting some oil past the rings and so it ends up in the tank. I had the cylinders honed and put new bearings, rings, and gaskets in but unfortunately the high pressure side just didnt seal up so good. Now the compressor works fine otherwise, it'll pump to 175psi no problem. So can I find a solution through an oil filter/separator? A new pump is $1K, otherwise I can order a cylinder for a little less than half the price and hopefully it seals this time. I know its not ideal that oil is getting past one of the rings but I really dont want to spend that much $ right now, any ideas?

About 6 years ago we had a similar situation with our wood shop compressor. Just like you we were getting oil which was contaminating our air supply. Bottom line...fish eyes from hell no matter what we tried to trap the stuff. I ended up biting the bullet and just buying the whole new pump assembly. I think I'd do some more shopping on that 1k$ pricing though. When I started shopping it out I was looking at $1200 and ended up finding one for $675 through a local wholesaler at that time. I know Eaton sells pump assemblies separately and might be able to match you up. They are at..... www.eatoncompressor.com

Thanks Darrel. Its a bummer because its just the oil and the **** cylinder is $450! I hear you on the price but I've called a couple of places and thats about the avg price. What kind of pump did you get?

It was just pure luck on my part.... my local compressor service company had bought a bunch of the exact OEM pumps from Campbell Hausfield in an inventory buy out. It was the 7.5 h.p. two stage complete unit. It was just a "bolt and go" with the thing as it was numbers matching with my unit.

Awesome score! Sometimes things work out, Im going to keep looking around for a bit.

If you just rebuilt it, you might give it some run time for the rings to seat since they are brand new. Also, did you make sure the rings were installed the right way. I don't know for sure about compressor pump rings, but I know on regular gas and diesel engines the rings normally have a certain direction they are to be installed to function as designed. There are markings on them as to which direction they go...for instance, the dot on the face goes up...Since it was honed, did you put in an oversize piston set? or is it now on the loose side. If it's loose and your tolerances are out, that could be something I'd look into as well. Also, what was the finish on the hone job? Rings usually call for a certain surface finish to seat properly.

All good questions. I had a machine shop hone the cylinder and yes it is a stock piston. I didnt measure the cylinders but it is only the high pressure side that leaks. The Low pressure piston (large one) is ok. I have a spare Champion R15 pump that I picked up very cheap and I may try to rebuild that one next, maybe I will call their service line and see what they say about honing the cylinders. Darrell, how did you get all of the oil out of your lines and tank? I havent hooked up this compressor to my air line setup but theres definitely going to be some oil in the tank.

Well, the air compressor service company I used did some type of purge on my tank when they did my new pump install. As for everything else....... you probably don't want to hear this but.... I literally replaced every single shop hard line and pitched all of my hoses. I cleaned and recycled all of my hi-flo air fittings by soaking them in alcohol.

Well I havent connected this compressor to my airlines so theyre ok but my tank will need some serious help. Im going to have to get creative...thanks.