A few visitors questions about air compressors that bog down when running. If you have the same sort of compressor issue, post a question at the end of this page to ask for some help.


The compressor bogs down at 20lb pressure and will not kick out?

by Scott
(Coraopolis PA)

When I turn the compressor on it builds to 20lbs and then the motor bogs down and wont kick out. There is a new pressure switch on it. They compressor sat for years without running so I drained the oil and refilled it. It still does the same thing. Any ideas.


Scott,

Are you saying that it worked fine after the many years of sitting, or are you saying that the first time you used it since it sat, it bogs down at 20 PSI?

Make sure your compressor is getting clean power, no extension cords, and check the intake filter to make sure it is clean as well.

More info, please. What make of compressor, what model number and what voltage?


When compressor does kick on, it sounds like the motor is bogged down

by Michael Byrd
(Lookout Mtn, Ga)

2hp motor air compressor. Initially builds pressure to 115 psi. After it turns of it sits, does not look or lose pressure .

When compressor does kick on, it sounds like the motor is bogged down and never builds pressure back. Stays around 20-30 psi and won’t build past this amount UNLESS I unplug the power cord and plug it back in.

I can’t find any leaks and upon checking the reed/ flappers.

I now smell burnt oil, the top of the valve smokes from burning oil and its very hot. So hot it melted the plastic threads on the filter housing!

So, I imagine I didn’t install the roads correctly . do I need a new reed/ flap set? Why will compressor build 1115 psi and then not unless power is disconnected.

I can’t afford a new ,used one and really need this air compressor to finish siding my home for homeowners. Any help is most gratefully appreciated.


Michael, you don’t indicate what make or size the compressor is, or what the power supply is. Tell me about the extension cord you are using. That may be an issue.

That your motor is overheating suggests that you’ve got…

a) a power supply problem
b) a motor problem
c) a start / run capacitor problem
d) an unloader valve that isn’t working properly
e) a valve / gasket problem


Compressor bogs down

by JC
(Northwest Ark)

I have a 60gal 3hp air compressor. Worked great til last week.

I decided to fix it up after many years of faithful service.

The 5hp motor was having a hard time so I got a new 3hp (No 5hps are available and since it was a 3hp head WhatTheHell) it worked great one time but the pressure switch was going out.

I replaced the bent and dented old copper tubes with new ones.

I replaced the switch but now Motor bogs down upon reaching 50lbs and motor STRAINS and pops the breaker. the head gets really hard to turn til it bleeds off thru valve by the pressure switch then it’s ok til it gets hard to run and the motor bogs again. NOTHING was actually changed in reguard to the head. Just the switch, motor and tubes. Why is it bogging down. I’m afraid I’ll fry the new motor at this rate. Why is the head acting up?? what can I do about it?


JC, this part of your post confuses me: “I have a 60gal 3hp air compressor” and “The 5hp motor was having a hard time so I got a new 3hp”

I surmise that you are powering it with 240 VAC as a 5HP sure wouldn’t run on 110 AC power.

If the original motor was a 5 HP, putting a 3HP on that pump would likely cause the problem. The motor bogs down because the it cannot overcome the load being developed by the pump.

If the original motor was a 3 HP, and someone put a 5 HP on it, perhaps they changed the sheaves then, and the wrong size sheave could contribute to the problem.

Remove, clean and replace the tank check valve and see if that helps.