Why do some shops recommed a timing belt and a waterpump not just a timing belt? Depending upon the vehicle if the timing belt drives the waterpump we recommend replacing the timing belt, waterpump and the tensioners all at the same time. This also includes flushing the coolant system if called for... Yes we can just change the belt but all of those components have been in the vehicle the same length of time. This increases the cost, some labor not usually alot and the cost of the additional parts. I really don't want to tell a client that we saved you money but now the water pump is leaking and we need to remove everything again in several months. Ouch. We base our recommendations on experience so that you the client gets the best value for your time and money.