Air Compressor Help

[christopheralan]

I have a Campbell Hausfeld HL4101 8-Gallon, 1.3 Running-Horsepower Oil Lube Compressor that has worked fine for years. For some unknown reason, it only fills to 25 psi. I can't find a leak anywhere. It just won't fill any higher. When not running, it will hold the 25 psi for days, so I don't think it is the tank.

Ideas?

 

[FredP]

does it stop running at 25 PSI? if so it is probably the pressure switch. if it keeps running but doesn't gain pressure it could be the reed valves worn out or the pop off is bad.

 

[christopheralan]

I turn it on and it just keeps on running. It builds to 25 psi, and just keeps going with no change in psi after that. I cut it off and it will hold the at 25 psi for days.

 

[FredP]

when it stops pumping is there a hissing sound coming from the pop off valve near the regulator? if not it sounds like the valves are worn out, you may be able to replace them. not sure. it may also be the piston rings. :dontknow:

 

[christopheralan]

nope, no hissing.

 

[FredP]

sounds like a new compressor is in your future. not sure a compressor that size is worth repairing. I have an oiless bostich 4 gallon dual tank that I may part with. it is like new. only a few hours on it. I think it is around 4.2CFM. not sure if this fits your needs. PM if interested.

 

[scsmith42]

Fred is correct - in all liklihood you have either a cracked reed valve or one with a portion missing from it.

Usually you can repair them - especially if it's an older compressor. They are typically located in the head bolted on top of the cylinder.

 

[Travis Porter]

I third the motion. One of the reeds. Download a schematic if you don't have one and you should be able to tell how hard or easy it will be to get to the parts. IIRC, I think M&S supply online carries parts for them (they are the supplier for my DevilBliss as well) and finding and ordering the parts was quite easy.

Strangely, enough, they were the parts supplier for my power washer as well. I ordered parts for my power washer and for my compressor at the same time and they even called me concerned that I had accidentally misordered something thinking I had made a mistake.

 

[rick7938]

I had the same problem with my small air compressor a couple of months ago. It was a blown head gasket. As the air was compressed, it was leaking into the intake plenum instead of being forced into the tank, so the pressure never got above about 20 lbs. I unbolted the head, scraped off the old gasket, put on some Form-a-Gasket, reinstalled the head, and it works like new.

Just be aware that if you have reed valves, they fit in recesses in the head and cylinder - one fits in the head and one in the cylinder. To hold the one in the head while I lined up the bolts and got them started, I put some heavy wheel bearing grease on the valve and stuck it to the head. Once the compressor started, the valve has worked great.

Have a look before you buy another compressor. Good luck.

PS: Take off the intake air cleaner, start the compressor, and listen for the sound of air being pumped back into the intake.