Drivebelt came off while on the highway (about 75 mph). Towed it home, went to replace belt and now both old belt (4 yrs old) and new belt (both 1025) are too long. Put on 1015 belt, topped off anti-freeze and engine cranks but runs hot. Why is specified belt (1025) too long now and what else may be messed up as a result of the belt slipping off?

I think your problem lies with the belt. If you are not putting the belt on correctly then the water pump my not be working need to double check belt routing this might be your problem. check accessory drive belt routing diagram in engine compartment.

Hi, when a belt comes off, it's usually because of a bad bearing in one of the accessories or idler pulleys, or maybe your tensioner spring is broken. Remove the belt and check all pulleys for spin and play. It is also possible you lost an idler pulley and the new belt routing is not turning the water pump in the right direction. Check the routing and look for a missing idler pulley. Let me know if you are missing the routing diagram.