IR compressor - loose or worn belt, or a capacitor or both?

by Dale
(Emerald, PA)

My 60 gallon IR compressor starts very slow with a belt squeal momentarily. The motor picks up speed after about 10 or 15 seconds and runs at full speed until full pressure is reached. Could this be a loose or worn belt, or a capacitor or both?

Comments for IR compressor - loose or worn belt, or a capacitor or both?

Click here to add your own comments

Jul 26, 2016
Unloader etc.
by: Bill

Glad you check it, Dale, as a failed unloader valve could lead to the compressor symptoms you refer to.

That the belt squeals on startup may also mean a loose belt, as you point out. Did you check the belt tension? About 1/2" play up and down in the middle of the belt should be good. If more than that, tighten the belt a bit and see if that helps.

If the belt tension is OK, dump all the air with the compressor off, pull, clean and replace the tank check valve. We're targeting this as it's the next easiest check to do. If the check valve is good, then you may be looking at a pump intake, high pressure valve, or issues with the pump mechanics.

I can see no reason why a squealing belt on startup should indicate a start cap issue.

Jul 25, 2016
Unloader works
by: Dale

That was the first thing I checked. It seems to,be working fine. It hisses and releases the excess air when the compressor reaches full pressure at 135 psi

Jul 25, 2016
Loose or worn belt, or a capacitor or both?
by: Bill

Not necessarily either.

As a first step in helping diagnose this Ingersoll Rand compressor problem, please monitor the compressor when it reaches cut out and shuts down to ensure that the unloader valve is working.

Click here to add your own comments

Add your own question or comment. It's easy to do. How? Simply click here to return to Ingersoll Rand Air Compressor Issues.