Can’t figure out why my new pulley is doing this with a new belt

[iboughtatahoe23]

you wouldn't have to change the water pump over it.. just take the belt off and clean the pulley with some brake clean. same with the tensioner and idler, wipe down the back of the belt and that should at least give you a fresh start.

if it kept doing it.. I honestly don't know. haha

I don’t know honestly to me it looks like the belt is getting too hot and treading rubber off onto the pulley I could be wrong. My water pump pulley doesn’t seem out of the ordinary are too dirty and I don’t see how it makes any contact with the other belt? On the same pulley? Yeah, are they touching? No

 

[Geotrash]

I don’t know honestly to me it looks like the belt is getting too hot and treading rubber off onto the pulley I could be wrong. My water pump pulley doesn’t seem out of the ordinary are too dirty and I don’t see how it makes any contact with the other belt? On the same pulley? Yeah, are they touching? No

This wear pattern/material transfer is completely normal with new pulleys and belts. It's nothing to worry about.