Vacume pump

[Thewespaul]

That could because the tensioner is siezed or because the belt isn't tight, pull that belt off and see if you can move the tensioner at all

 

[pelky350]

I'm gonna pull it Off and change it out it looks kinda old anyway, it's a coworkers truck that stays parked a lot so I don't see it very often. It's been like this a while I think, the pulley on the vacume pump looks worn from slipping so much I think

 

[pelky350]

So changed the belt and it seemed to work for me, then they drive it home and about ten miles from here the brakes got hard again. Probably the vacume pump