I had my compressor on the other day and went out to do some yard work. Came back in and the shop had burnt rubber smoke. The compressor belt was broken and burnt. Thought it broke and jammed on the cover and motor pulley.
I got replacement belt and installed it. The compressor cuts off at 135. The unloader valve started leaking at the switch connection. Thought the switch might be bad so installed a new switch that came with a new unloader connection.
Ran it up to 135 to see if it would cut out and it did, but it was really blowing back from the unloader connection on the switch. And it seemed to take longer than usual to load up to 135, but that may be because it was absolutely empty. Not only that, but the pump seized when I went to restart it.

Hit me with a 2X4.... Obviously the pump seized and that was the reason for the belt burning and breaking. The glass window on the pump showed I had plenty of oil. I went to drain it and very little came out. ???? I ordered a new pump because it was under $250US. I am taking the old pump apart to see if there is any noticeable damage. So far I don't see anything, but I don't know what the specs would be for cylinder, just looking for pieces.

I forgot to mention that the oil filler cap with the vent holes was blowing out air when it was running. I don't know the mechanics of a compressor, but would that have something to do with the reed valves in the head?

The compressor is a single stage, 5HP 60 gallon compressor.

A day without laughter is a day wasted- Charlie Chaplin
When wrestling a grizzly bear, you have to keep at it until the bear gets tired, not when you get tired.
1948 Chevy 2-Ton