Diagnosing Air Compressor

[3liter914-6]

I bought an old, large, and pretty ugly compressor around a year ago, and lately it's been giving me some issues.

It typically pumps up to 60 or 70 psi without any issues, but towards the end of the pumping, when it gets to 80-90-100psi it starts to makes a stalling or groaning kinda noise, whirr-whirr-whirr-eh-eh-whirr , and will often trip the breaker especially if it's refilling or I'm running it to over 100psi. I changed the oil out today, and the old stuff (month or so old) was pretty clean and it didn't seem to have used any.

I'm inclined to believe it's the pump itself, but I'd hate to replace/rebuild the pump and have it actually be the motor. Any way to troubleshoot?

 

[Blacknwhitepit]

A few questions.

Is it a Hybrid (Frankenpresser)? I.E. Made from different compressors?

What Amp circuit are you running it on?

Are you running it from a different plug than you did before? Are you using an extension cord?

How long ago was it since it was running to standard?

Is it a direct or belt drive?

What is the brand?

What kinda switch is on it/ rating? ... IE (95-125) PSI

-BWP

 

[rsanter]

what type of compressor?
there are a couple of things that can go wrong with the compressor itself. if the rings are worn it can pass some oil and the oil can clog the reed valves a bit because as the compressor runs for a while the heads will get hot and the oil that makes it to the reed valves can become carbonized because of the heat. this carbonized hardened oil can cause problems in the head including compression leaks and blocked passages.

the oil will look good as long as the bearings are not bad. bad bearings can heat the oil in the bottom end or can put metal filings into the oil.

try to find out how much a gasket kit, and reed valve kit are because it may be relitivly cheap to open and clean the compressor.

one option is the next time it displays the problem, turn it off and remove the belt. turn the pully be hand to see what it feels like. do the same when the unit is cold/cool

bob

 

[Vicegrip]

sowing down at higher head pressures could be from the wrong motor, the wrong voltage, the wrong pulley on the motor or a host of other things.

 

[3/8"indestro]

pictures would be nice.gives a basic idea of what were dealing with.

 

[Jeepguy]

it sounds like a motor problem, like its drawing too many amps. you dont have it on an extension cord do you?