Osborn compressor making a banging sound and will not hold much pressure.

by Stephen Spencer
(Decatur, IL)

I have an old 100 psi air compressor. It was made by the Sanborn MFG Co. Model #34A50-10. I payed like 25 bucks for it 4 or 5 years ago. It was well taken care of and has ran great for all this time till now.

The other day it started a banging sound coming from either the compressor or the electric motor...can't tell really. It will only hover around 40 psi.

My father said to take the air hose off and then tip it over to drain any water or milky substances from it. He said that he needs to do his every so often and it works. I tried that and nothing came out and it is still doing it.

I hope there isn't a clog or somthing and I'm afraid to run it like this in the event of serious damage. Is there a air intake filter on this model? Keep in mind that I'm not too mechanically inclined to try to figure this out on my own. I have inclosed pics of it.

Thanks
Stephen

__________________
Bill says...

Stephen, a clanging sound suggests to me something mechanical, and you need to be able to determine if it's the drive train or the pump.

I see the belt is shrouded from the photo side. Can you see the sheaves looking at the other side. Is the belt hitting something?

If so, I suspect you may have a mechanical issue with the pump. Since I cannot hear the noise, it is difficult for me to try and pinpoint.

If the motor is running correctly, and the pump itself is compromised, that might cause belt jump, and that may be the source of the noise.

That the tank pressure doesn't go past the 40 PSI mark suggests to me that it might also be a pump valve problem.

Bill