Serpentine Belts on a ISX

[Waterloo]

I change mine out once or twice a year, I hear anything I think is belt related I change the belts, both of them. Also, inspect the top tensioner pulley. I have replaced this tensioner pulley three times, the one closest to the AC compressor, they are good for around two years on my truck for some reason? I have a Gates brand pulley on there right now, put it on just before the in frame. Maybe it will last longer than the OEM ones, and it was half the price.

I would keep doing what you are doing, you know as well as most of us here, you cannot PM these trucks to much, and belts are cheaper than the alternative.