A defective Water Pump creates overheating problems to your Outboard motor and could lead to a bunch serious potential damage. This is why we always check your motor for incipient and/or obvious overheating signs as part of our Annual/Periodical Service. If our diagnostic points to a Water Pump problem, and after informing our customer and get his/her approval, we always change the whole Pump instead of just any part(s) of it as a standard procedure for 2 reasons: a) we always need to guarantee your Water Pump is 100% operational, and b) the labor charged to you is always the same, since what sets its cost is the removing and re-installing of the lower unit, and not the Pump itself. That little extra money goes totally to your benefit, not to ours!