I just finished swapping in a good used ps pump, along with putting on a new serpentine belt. However the belt is not riding on the center on the tensioner pulley, even after stopping engine and repositioning belt. Upon removing the old belt, I discovered it to be the wrong part number, 0.4 inches shorter than the correct size (which is now on). The belt is riding extremely close to the bracket, but doesn't appear to be touching. Pulley appears to be in spec according to shop manual, but maybe it isn't.

Anyone experience this? Time to change the tensioner, or just the pulley?

 

Did you get a PS pump from another GS or did you use one off of an SC or something. Sounds like some pulley isn't on straight and is causing it to slide to one direction.

Other than that, I would go ahead and replace the pulley I suppose. The tensioner doesn't really go bad, until it doesn't hold tension any more, so that is probably not the problem.

 

It was sold as one from a 93 GS300, just like mine. Looked identical to the one I took off. I just put a straight edge on the pulley and compared it to the belt line; parallel 100%, no deviation.

 

The PS pulley is where I placed the straight edge, just to clarify. There was no play when I had it on the bench

 

This is normal as long as the belt is not rubbing anywhere you will be fine