I have a '90 Fullsize Bronco, with the 5.0 EFI. I recently went through some mud puddles and the serpentine belt started squeeking. I got home and sprayed it off with the hose. It stopped the squeeking but got real loud, (kind of a grating noise). I sprayed some of that belt dressing on and it seemed to stop the noise, however this fix was short lived. I decided to further inspect the belt, so I removed it and it was very greasy and sticky, probably from the spray. I cleaned it up the best I could, along with all the pulleys, put it all back together and it still makes the loud noise. I have checked all the bearings in the various pumps and pulleys and they all seem to be OK. Is it just time to get another serpentine belt or is there something else I can do? Any input will be greatly appreciated. Thanks.

 

First off, never use belt treatment on a serpentine, almost never works. Its time for a new belt, your old one is more than likely glazed over, thats why its slipping, the water just spead it up. Get a new belt, and clean the pulleys with some brake cleaner, and make sure the tensioner is working corectly.

 

Probably obvious, but make sure the engine is cold and all the electrical is dead before you go spraying anything like brake cleaner under the hood.

 

Thanks guys that's kinda what I figured.

 

The tensioner pulley on the truck has a guage near the edge of the arm that shows how far the belt has stretched. Once the gauge pointer is no longer within the bar stamped in the arm, the belt needs to go.