So the timing belt service was done before I got my GS400 and I cannot verify whether or not the water pump was done.

With this in mind, what is the expected life of the water pump on the GS400?

Thanks

 

on almost all cars the life of a water pump is 90 to 100k this is why that particular service is so expensive

 

Maybe you're thinking timing belt?

 

mines was replaced at 130k.. it was leaking

 

it's all relative; there's an es300 on the forum that made it to 240k miles on one water pump. people change the water pump at 90k miles because they're also changing the timing belt, and you cannot take out the water pump unless you take off the timing belt.