[Mac88]

Ok, I cleaned up all the valves and replaced the gauges on this old compressor (Craftsman Air compressor Model Number: 919.176840), but now that I'm putting everything back together, the belt keeps jumping off the flywheel and pulley. Is anyone familiar with this compressor? I'm not sure whether the flywheel is pulley are'nt aligned correctly or whether I just dont have enough tension on the pulley to keep the belt tight.

[bigdog7373]

Probably not aligned. Or maybe warped/bent?

[Pantaz]

Was it operating okay before disassembly? Do you see any wobble in either sheave?

Also, make sure the new belt is not too wide for the v-grooves.

[Mac88]

I did'nt see any wobble but I'm sure it's possible. I was trying to avoid taking it to a repair shop just to replace I belt but I guess I may have to. Thanks for the replies.

[crownver]

Personally, I wouldn't take it to a repair shop for that. Does it throw the belt as soon as you start it? There's only a few things that can cause a belt to come off, most of which have been touched on here. If there's enough wobble in the pulleys to throw the belt, you would certainly see it. You shouldn't need that much tension, but the belt shouldn't be loose either. You can check that the pulleys are in line with a straight edge. One other thing that could throw the belt is something internal jamming up the rotation, either in the pump or the motor. Or possible the motor mounts are loose and tension is lost while running.

[Mac88]

Thanks for the reply. I'm going to go mess with it a little more later on and see what I can come up with. But there are no mounting bolts, just a little small tensioner.

[crownver]

Good luck and let us know how you make out.