Air brake compressor questions.
I have a 1989 ford b700 with a belt driven bendix bx2150 compressor for the brakes. I'm having issues with alot of squealing coming from the belt. I know the belt is a little loose and I will tighten it to see if it resolves the squealing. My main concern is once it warms up a little bit it appears that the pulley on the compressor is skipping, stopping for a split second than continuing to spin. I shut off the bus and turn it back on a few minutes later and she spins freely, and quietly for the remainder of the time I leave the motor on. Also when I restart it appears the belt is dancing less than on initial start up. Would a loose belt not riding the pulley with the correct tension cause this, or do you think I'm looking at a bearing for the compressor pulley? I'm baffled as to why it is fine after a restart. Any and all helpful advice is appreciated.