The rbuild kit for these air cooled portable compressors came in, I'm going to order another one, I'm not sure if this rebuild will last long or not.
I thought the split rings were the ones going to be replaced but those aren't part of the kit. It comes with o rings and the solid wear rings. I replaced all 3, a small and large ones in the compression area and a medium size one that the pump rod goes through. I also replaced the check valve that has the spring on it. The kit has other pieces that as far as I can tell aren't in my compressor.
The small ring in the compression area was deformed when I originally took the pump apart and I assumed it was due to use but I don't think so now. These rings deform when you installl them and the outer diameters seem to be a few thousanths too large. The ring deformations go away. I had to force the pump pieces to go over these new wear rings which didn't treat them too nicely. The small one deformed almost identically to the one I took off and the large one had a piece knocked off of it. All of them got shaved by the metal pieces going over them.
I'm not sure why but o rings are used underneath the wear rings, I replaced those also. I was able to use silicone 'grease' on the pump shaft this time like he recommended. Honestly with the 'chunk' taken out of the large ring (enough came off that I can see the o ring under it) I was expecting to have to take it back apart and put the old rings back on until a new kit came in.
I'll lightly, slowly and carefully sand down the next set of rings so they won't get so damaged next time.
I was pleasantly surprised that it worked and pumped well. I'd say pumping time sped up more than I expected it to, wild guess I'd say about a 25% increase and the temp stayed much lower the whole time also, previously at 10 minutes it was hitting 100 deg F (38 C) but this first time after the new rings were put in it never got over 89 F (32 C).
After the original cleaning/lubing I was pumpinging 300 psi each time hitting 38C at 10 minutes. Now after the new rings it pumped a good 1000 psi (2800 to 3800) in 10 minutes and only hit 32C.