F600 371 V8 - power steering belt jumps off

[Carl Shannon]

I have a 1973 F600 371 cu and the power steering belt keeps jumping off. The fluid is full, i've tightened the bolts down as hard as I dare without breaking them off, soon as i turn the wheel the belt jumps off.

Any ideas?
 

[Jon Hagen]

Something bent, worn or broken in the pump mount allowing it to run out of alignment under load ?
 

[Carl Shannon]

Doesn't seem to be, but the first bolt hole end is broken about 1/3 off, still tight though.

I can only see 3 bolts in a line, not any keeping it straight, am i missing something?

Thanks
 

[ericlb]

first look at the belt itself, see if the belt has fliped over or has a 'broken back' it will look like a kink in the belt if so that will make it come off under load, if its ok, stand beside the truck with it running observe the pulley on the ps pump, as well as the fan, crank and anything else that belt runs all the pulleys must run true and be in line with each other, exactly in line with each other, if needed repair so that they are, if they look ok too, pull the belt off and carefully inspect the pump pulley for cracks, letting it flex under load or see if the shaft the pulley is on has any wobble to it
 

[Carl Shannon]

Spent some time on it again today...

The belt does loosen up when just running and no load, but still turns. I let it run for a few minutes and the pump started making a lot of noise. I'm thinking that it may be bad, I have another F600 that I can borrow a pump from, see if that is the problem. I think it is.
 

[Carl Shannon]

So, the power steering pump is finished. Anyone know where I can get a power steering pump for a 1979 F600?