Compressor troubleshooting

[jeep63]

Hey guys,

I have an older Craftsman compressor. It is a Oil lubricated, single stage, twin cylinder, compressor. Model 919.184191. It is roughly 10 years old. 5 years ago I had a problem with the reed valves, so I replaced the intake and exhaust valves. This worked great.

I came back from vacation and when I opened up my shop doors the shop was full of a blue haze. I had seen this before and knew it was from my compressor, but I had never seen so much and I was always around when it started. This time I don't know how long the compressor ran before it tripped the thermal overload! I don't typically turn my compressor off, and now I see this as a mistake.

I took the head apart and the valves were all crusted in carbon, a lot of carbon! The piston heads too were crusted, but they were not seized and I can turn the pump by hand.

I cleaned everything up, except I did not put new rings in. I put in new valves (intake & exhaust) and polished all the carbon off. That was quite a task. I reassembled the pump and changed the oil. After turning it on, I notice air blowing out the intake and the pressure only gets to 60psi.

Since the intake valves are new I am at a loss for what is causing this. Any ideas?

 

[Davefr]

Never ever leave an unattended compressor on!! You're lucky the thermal overload did what it's supposed to.

You didn't mention head gasket. That would be my first guess.

 

[jeep63]

Yes, I replaced the head gasket and the valve body gasket.

I suspect the rings only because I did not do them, but I am not clear on why that would cause the problem. Regardless, I have to tear it all down again anyways.

Of course the ring kit is listed as no longer available from Sears, but I learned that Devilbiss made the compressor pump and I found the kit elsewhere.

 

[pop pop]

Reed valves are not seating.

 

[highcarbon]

couple of things might be going on first, are you sure the reed valves are seating right? Somebody already mentioned this, and without pictures it is hard to tell, but I test the valves by taking the valve assembly plate and put water in the holes the valves seal off if it leaks water it probably wont hold air.
Next might be a warped valve plate assembly from getting so hot.

another thing would be the check valve stuck open this would be the valve usually brass that screws into the tank that the line from the head goes to

Just a couple of possibilities

 

[tavernaut]

It's rings. The blue haze is oil getting past the rings and getting blown all over the place. If your compressor's always made this haze, it's always had a ring problem.

Reed valves don't seal like poppet valves; compressors always blow some air back through the intake. So that puffpuffpuff at the intake is relatively normal.

 

[jeep63]

Thanks for all the tips. I am 100% the cause of the issue. I put the gasket for the head on backwards so there was a hole on the intake side between the valves that was open and let all the air our. I feel like an idiot.

Now since I have it all apart and I did order a ring kit along with a new gasket, I am thinking of changing out the rings.

Given the fact there have been issues with oil getting past the rings it is probably the "right" way to finish this.

I will take a picture or 2 this morning to show what the cylinders look like.




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[jeep63]

I finally got time to work on my compressor pump.

I pulled the crankcase and cleaned it up.

I pulled the pistons, cleaned them, and replaced the rings

It is all back together and runs great. It is quiet again and fills the tank quickly.



I am psyched to get back to my jeep work now.

 

[C96]

Great Job!