I replaced a bad thermostat. Didn't tighten it down properly, had some coolant leak out during a trip around the block. Fixed the leak, now my belt/pulleys are squeaking like a banshee. I took off my belt and washed it down with soap and water. I used a hairdryer to dry it completely before putting it back on. I cleaned each pulley all the way around with denatured alcohol. Still squeaks... So I replaced my idler pulley because thats where I thought the sound was coming from. Still squeaks...

Question: Instead of replacing every part on my truck, what would be the next part you all recommend replacing to try and chase the sound?

Thanks.

 

WD-40 each pulley one at a time till the squeak goes away.