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We have a 1997 Toyota Caldina, and had the cam belt changed at 100,000km.

At the time, the water pump wasn't changed, and now 60,000km's later it has failed damaging the new cam belt.

Luckily, we caught it in time and no other damage has been sustained, but we are still facing an expensive repair bill.

Is it usual or standard practice for a mechanic to recommend replacing the water pump when the cam belt is changed?

We are now wondering why it wasn't done, or recommended in the first place.

Kristina,

From the "Ask Jack" archives - 8 September 2009

It is not standard practice to replace the water pump when the cam belt is replaced but it is advisable in many cases, and we do support garages who make this recommendation to their customers.

In many modern engine designs like in your Caldina, the cam belt is used to drive the water pump. When you replace and tension a new belt it can often introduce increased load to the old water pump bearing resulting in a failure such as you have experienced. It can never be said for certain the water pump bearing will collapse but then again a mechanic cannot guarantee it won't.

For this reason it is often recommended the water pump is replaced at the same time as the cam belt and while that particular part of the engine is apart. The additional labour cost to replace the water pump at this time is insignificant.

As good workshop practice the mechanic should have discussed this with you and left the call in your hands. For some motorists it is a risk worth taking as they are on a limited budget or intend selling the car in the near future.

In some ways you have been very lucky getting 60,000km's out of the old pump, we have heard of many cases where failures have occurred within weeks of a new belt being fitted.