Make sure the pulleys aren't rusty causing the belts to get real narrow, they then can't be tightened down enough to stop squeeling.
Then put on some new belts and make sure they are tightened properly.
Loose belts get glazed and always squeel,
The Best Belt Dressing to get 1 more lap out of a marginal belt is;........
A bar of Lava Hand Soap.........
The Pumice in it will sometimes get you by, til you can Replace them.......
