It's an oil-less compressor. Well this is a real simple piston/crank/sleeve combo. Nothing to adjust. The ring comes premoulded to the piston. The ring is made of some sort of hard rubber/leather. The cylinder wall isn't much more than a pop can. My guess is that tolerances never came to mind when designing this "Craftsman" compressor. Just sayin'
What I ordered is supposed to be a direct replacement for my model. This is what it
is. Now here is something I noticed that may be of interest. When in compression stroke there is much resistance. That is to say with all valves open. I would think there would not be resistance. But then I'm not sure what is going on in the head of the unit. I assume that the air goes through a check valve into the tank. Fairly simple?
I just got done replacing my piston and sleeve in my 3 1/2 hp Craftsman Oil less compressor. Wish I'd seen these, I bought mine from Sears.....
This is the second time I've replaced the piston and sleeve. When first got the compressor it seemed to wear out in under a year. Replaced it and it lasted for nearly 20 years. Must have improved it some.
Was going to replace it when it needed replaced this time, but looking at new ones, I found none that rated very well on the different sites. So I decided to just rebuild this one again. I also replaced the check valve in mine.
When you replace the piston and sleeve you should run the compressor unloaded for 15 to 20 minutes for break in, allowing it to not build pressure. I usually leave the drain clear open and the regulator open too.
John
