These coolant sealing tablets fix a variety of leaks. My water pump weepage seguayed into a leak. I had to fill my reservoir on a daily basis! As the Water pump replacement entails the removal of the timing belt, I decided to try these tablets. Simply crush them and deposit into coolant tank or radiator if you have a non pressurized reservoir. Worked like a charm. 3 months later, and no more leak. Always carry these in my vehicles. Give them to friends and loved ones.