do you need to change the water pump when you change the cam belt?

If the water pump is driven by the cam belt it should be changed. If the pump fails it can break the belt. On most engines when the belt fails the intake and exhaust valves will hit the pistons, wrecking the head and possibly the pistons. The repairs required will cost more than many cars are worth.
In short, listen to your garage, change the pump!

spenny
November 2009

It does'nt have to be replaced but while it is accessable it's a good practice to replace it at the same time, as if it fails in 100 or 1000 miles time the timing belt will have to come off again, and it's not good practice to refit an old belt so you would then have the cost of yet another timing belt and all the man/hrs costs again

nigel
November 2009