Craftsman Model 919.167780 2 Stage Oiless Air Compressor

[twb60]

Through the years I have had several oiless air compressors that failed. I always purchased new cylinder and ring along with any new head gaskets or orings and the "rebuild" worked. My father in law gave me a Sears Model 919.167780 Serial # 2116127039 that would no longer pump up to cut out pressure. He had disassembled it and ordered parts, but only received parts for 1 cylinder. It is a 2 cylinder unit. Attaching a pdf of a document I put together describing my issue along with pictures. I don't know what else to do with it and hope someone here has had a similar experience and can offer suggestions.
Thanks - Tony

 

[ohhimark]

Does it hold the pressure that it builds?

 

[The Cobbler]

some of the pictured clearances seem a bit of a concern, but I don't see that causing your issues . at most it would add to noise & maybe vibrations.
even inferior rings should last a while I would think. I dunno, I am lost but I would check the fit of the reed valves, the seal faces of the housings they attach to and double check everything for leaks . I recently rebuilt a single cylinder with the same cyl/ring and left the fan off to leak check everything . I used the cheapest I found on ebay and they worked great. much to my demise, there is a small tank leak at the weld on the bottom bung.
Oh, and one of the Oring seals with the kit was boogered, so I used the old one

 

[bonneyman]

Totally left wing here but when I was doing refrigerators they came out with oiless compressors as a "better, cleaner, more efficient" design. Just cheaper as it turned out. I saw more of those things fail, and often we'd just swap it out with an older style oil compressor to get the reefer running. I thus didn't really trust oiless compressors after that.