Oil less air compressor hard start

[vrinner]

So I have an older Craftsman 50gal stand up compressor that I rarely use in my house garage but nice to have it there. Went to use it and noticed it was very hard starting and then once it got going was good but the next cycle it wouldn't start and then tripped the circuit breaker.

Are these things like A/C units where they have a run capacitor or something in it for startup? Any advise on troubleshooting?

 

[finn]

There should be a check valve in the system that dumps pressure from above the piston after the motor stops. If that valve fails, tank pressure acts on the top of the piston, making it difficult for the motor to rotate the piston from stop.

My pancake compressor has a failed valve. They only cost a few bucks and are hanging on the wall at Tractor Supply and probably many other outlets.

The Craftsman is probably made by Campbell Hausfield, just like my Porter Cable pancake compressor is.

 

[rlitman]

There should be a check valve in the system that dumps pressure from above the piston after the motor stops. If that valve fails, tank pressure acts on the top of the piston, making it difficult for the motor to rotate the piston from stop...

The check valve is a spring loaded ball inside the fitting on the tank where the line from the pump enters. I doubt this is the issue.

There's also a part called an unloader that should release the air in this line when the pump is turned off. There should be an audible hiss for several seconds when the pump stops. If your check valve is leaking, the hiss will not stop. If your unloader is stuck, it will not hiss.

Yes, there's a motor capacitor. It sure could be bad.

 

[vrinner]

Great...thanks for the replies. I'll have to dig into it this weekend!

 

[rlitman]

Oh, one other note, compressor motor caps get vibrated badly. Make sure that the wire connections are tight.

 

[vrinner]

So it ended up being a broken bracket in the back that was causing it not to start. JB weld and its good to go