Viair 400C compressor

[rusty_tlc]

Last summer I picked up a Viair 400C at a garage sale for cheap, not sure what I paid but probably less than $10. I finally got around to powering it up last weekend. At first the motor ran but no output. I noticed some glue on the intake hose barb, when I removed it the hose barb was filled with glue. Cleaned that up and got some air out but not a lot of pressure. So I pulled the head and cylinder. The cylinder is scored and the piston seal is hard as rock.


Viair does not sell just the piston seal, they sell the whole piston, bearing and counter weight, $51.50. A new cylinder is ~$37. So for less than $90 I could basically have a new $190 compressor.

If I can make what I have work it would be even less. I noticed that the piston stoke covers less than half the length of the cylinder so I think I can just flip it over and be good. I put a little Multipurpose grease on the piston seal and gained some pressure so I'm wondering if there is a way to recondition the seal material so it will do it's job again.


Any body have any ideas?

 

[rusty_tlc]

The piston ring is PTFE, it's one of those cup designs like the leather in an old fashioned bicycle pump.

 

[cruiserjunkie]

Maybe a hydraulic shop might carry a similar type seal you could use

 

[rusty_tlc]

Great idea there is a place around the corner from my office.

 

[cruiserjunkie]

Was looking at rebuilding my floor jack and noticed some replacement seals are still leather guess plastic still isn't the cure all. Or maybe the rebuild kit is nos either way good luck