I have a 2005 Lexus LS430 with 50,000 miles. I have been advised to repace the belt and therefore I should consider replacing the water pump at the same time. Ther are no symptoms. There is a fear factor should the belt break. Am I being hustled?
If the water pump has to be removed from the engine to replace the timing belt, then do it. The pump is not all that expensive. But 50,000 miles/5 years seems early to replace the timing belt. Toyota should have a recommendation in your owner’s manual or an accompanying maintenance log. What does it say about timing belt replacement? It is often around 90,000 miles or more.
Your getting hustled unless there is any other reason, like an fluid leak or engine repair that may have damaged the belt.
My guide tells me this belt is good for 90,000 miles or 8 years. Yours is only 50,000 miles and 5 years old. If everything else is OK, that belt should have 40,000 miles and 3 years left on it.
Do verify the recommended replacement - pay attention to both time and miles. Sometimes the time recommendation is 6 yrs so you may be coming up on it.
Waterpumps are almost always done with timing belts b/c, as jtsanders notes, it is often part of the labor anyway. In the long run, on average, it is cheaper to do this since a leaky water pump will have you paying for the same labor all over again.
A timing belt that is old or worn will give no signs or symptoms. It will simply break and the car will stop dead without warning. On some engine designs this event will immediately ruin the valves and lead to expensive engine work. The only way to do it is with the time/mileage recommendations.