Faulty air compressor (shop)

midnight sun · October 20, 2007, 06:44:51 PM

I believe my shop compressor is going TU. Seems like the past few weeks its taking longer and longer to get the pressure up to 120. Today it ran for over 45 minutes trying to get from 60 to 120 and never did make it. I finally shut it down. No leaks anywhere at least that I can hear. Anything else I should look for? Its almost 10 years old but its not like it runs every single day 10 hours a day. Im just trying to figure out whether its worth it to R&R the motor or just spring for a new one.
This one is an oiless single stage 60 gal. 6 hp.

TIA

midnight sun · October 20, 2007, 06:45:50 PM

By new one I menat a new compressor not a new motor.

Crosley.In.AZ · October 20, 2007, 08:48:04 PM

buy a new one... non oil- less IMHO. Cast iron pump dual stage , it will run for decades .

the oil-less style units do not seem up to a large task.

kb426 · October 20, 2007, 09:16:38 PM

About the only thing that goes wrong is the valves. Most have reed valves like a 2 stroke. Pull the heads and see what is there. It might be repairable for very little. I bought a Belaire 218V a couple of years ago. I've been very happy with it. It's an 80 gallon upright.

ONE37TUDOR · October 20, 2007, 09:26:56 PM

If it has an air filter on it and if it has gotten extreemely dirty for some reason it could impact the amount of time it takes to build up air?

Just a thought.

Scott...

wayne petty · October 20, 2007, 11:24:42 PM

some oilless compresors had carbon/graphite split rings on the pistons and these are replaceable..
.

and another link for various appliance and tool parts

http://www3.sears.com try it...it's amazing the illistrations and part numbers they have

Woody2B · October 20, 2007, 11:31:06 PM

Someone gave me an old Craftsman 5hp, two cylinder that was worn out. I figured I would try a quick rebuild on it before I did anything else. I ran a 3-finger hone to rough up the cylinders, then removed and polished the reed valve blades and seats with scotchbrite, and reassembled it with the old rings. It pumped up like normal to 145 pounds after that so I cleaned it up and painted everything so it looks like new. I've got about 8 bucks in the whole deal.

Bugpac · October 21, 2007, 06:54:51 AM

you got an oiless to pump to 145, thats amazing....I to bought a 80 gallon bellair, they arent cheap, but a * nice machine, In my other shop i also have a 80 gallon sandborn, it is on its 13 or 14th yr right now....Still ticking...

Bruce Dorsi · October 21, 2007, 12:12:45 PM

I'm not sure if this applies in your case, but most compressors have a check valve between the compressor and tank.

I have been told that if this check valve hangs open, the compressor will run much longer to pressurize the tank.

midnight sun · October 23, 2007, 09:21:22 PM

Quote from: "Bruce Dorsi"I'm not sure if this applies in your case, but most compressors have a check valve between the compressor and tank.

I have been told that if this check valve hangs open, the compressor will run much longer to pressurize the tank.

Tore it down yesterday. Pretty funning looking. The so called piston is just a disc with the ring surrounding it. It screws onto the top of the rod. The cylinders are ceramic I believe. Anyway the rings were shot and had also scored the cylinders. on both sides. My new parts are suppose to arrive tomorrow for the hefty price of $32.00. Hopefully be back in business in a few days. The check valve and the reed valves were a little dirty but cleaned up nicely.

Thanks again for all of your advice.