black coating came off new Serpentine Belt
 

I put a new serpentine belt a few weeks ago a daco poly belt on my 95 f 250 (4x4 351w).anyway I been geting sqeeking from the belt the last few weeks and sprayed all the pullys with wd40 and belt spray to stop the sqeek few days later. Now about 4 days later I see some of the black coating from the belt on the idler pulley and i can see on the 2 week old belt spots where the belt coatings coming off.you think the wd40 did this?seems kinda odd cause i here people use wd40 to stop the sqeeking.IM guessing now I should buy a new belt again?but I wanted to try a another brand belt and advanced and auto zone only sell 2 belt for my truck the poly belt and another belt both made by dayco im pretty sure thats about 5 bucks cheaper.my question is why would these sprays make the belt do this and why dont they sell any other brand belts now i have to go buy the same belt again 2 weeks later new.

I wouldn't ever spray WD40 on the belt. Probably making the belt slip issue worse..

Go buy a goodyear gatorback belt and dont look back.. Like we told you in your last thread about this ;)

Yea, my money's on the WD-40. I'm pretty sure its a no-no using that on belts or hoses-petroleum & rubber don't mix.
Roger