Can water pump ruin serpentine belt?

My 98 voyager serpentine belt fell off again this morning during heavy rain, I kept on driving hope to reach my mechanic store, but the heat build up so fast it overheated just in a few block, I have no choice so to drop my car to auto repair shop nearby. They said the water pump is bad and it ruins the serpentine belt, then quote me to replace the water pump and serpentine belt, I wonder can water pump ruin serpentine belt?

If the water pump seizes it can cause the belt to drag on the pump pulley and overheat, stretch and fail.

Bear's explanation is technically correct, but I have to say, of the water pumps I've heard about on this board on these vans, the common failure mode is more along the lines of it starts to leak, rather than bind up. I've replaced my WP on my '97 for that reason as well. But then, you may just be the lucky one :)

That being said, your water pump may well be on it's way out, but I would check to see if it's leaking first (or hard to turn the impeller shaft). I find the most effective way to see if it's leaking is to hook up a cooling system pressure tester (http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=76291&group_ID=1901&store=snapon-store&dir=catalog) to the radiator, but you can run the engine and look for leaks as well if desperate.

Now about the serpentine belt coming off....This is apparently a very common problem with these vans. Apparently, there has been a solution to this problem, produced by Gates, which is basically ribbed pulleys on the serpentine belt idler and/or tensioner pulleys. The cost is only slightly more than what it would cost to replace the tensioner, idler, and belt with quality parts. If your van has this problem, this is the best solution I've heard to avoid needing to drag around a spare belt and serpentine belt installation tool. I was initially very skeptical about this "magic fix", but have since been otherwise convinced. See this thread (http://forum.chryslerminivan.net/showthread.php?t=4693&highlight=gates+fix) for details

if you have a 3.0L here is a link to the gates fix kit
link:
http://www.midwayautosupply.com/pc-7816-261-gates-gates-system-solution-micro-v-kit-for-chrysler-30l-engines-38342k.aspx

if you have a 3.3/3.8 gates also has a fix kit on their site.
these kits can be had a napa and other parts stores. mike

I have experienced my serpentine belt coming off my 1996 Grand Caravan 3.3 on three (3) different occassions.

The 1st time was when the tensioner pulley bolt sheared and caused the belt to slip out of its pulley. Replaced the tensioner and the belt stayed on.

The 2nd time I had a problem was when the power steering pulley (made of hard plastic) cracked and ruined the belt. I replaced the pulley with an after market brand, a new tensioner, and a new belt and the van was back working again.

The 3rd time the belt slipped, I put it back together, run the engine and noticed that the belt tensioner pulley is slightly misaligned. It seems that the tensioner bolt (mounted to the chassis) or the spring is not aligned straight and causes the belt to slip. I replaced the tensioner (again) and a new belt and everything is working fine.

I consider this problem is a safety issue because you might be driving in the freeway and suddenly the belt comes off and you lose power steering cooling system. It is known issue with Caravans as widely reported in the National Highway Traffic Safety Administration (NHTSA). Dodge does not acknowledge this as a safety issue.

I hope my reply helps.