air compressor keeps popping oil fill plug out!

[dwcopple]

When the compressor kicks on to charge the oil fill plug pops out now. Seems to be holding air fine. Why does this happen? It is a 5hp 8 gallon Campbell Hausfeld.

 

[JTK]

Is there a lot of hours on it? Some small portables have breather holes drilled through the oil filler cap, or a separate breather elsewhere on the crankcase. I'd look for clogs/plugs @ the breather.

Other than that, it could be worn rings or reed valves causing excessive blowby.

Joel

 

[Chris142]

My old compressor has lots of blowby. i added a couple ft of pipe with a k&n breather on top of the pipe. looks funny but works

 

[user52165]

Is this not a threaded plug? 5 HP and it's not threaded?

 

[dwcopple]

nope, two o-rings on a dipstick

 

[edwardh1]

if campbell answers the phone call them?
chinese made