I replaced my water pump and also got a new belt. How do you set the tension so you know that it is correct? Is there a special tool? The tensioner roller assembly has a square hole that is probably where a tool goes in to force it out to the correct tension. I tried to use the end of one of my socked extensions, but when I started the van back up, the belt came off.

Any help would be appreciated.

The belt tensioner should be spring loaded and provide the correct tension automatically. If your is no longer spring loaded it is bad and should be replaced.

He is right, its spring loaded. either frozen or they gave you the wrong belt.

Thanks! I was able to get it on correctly.