Should you use water pump gasket sealer
The most common question I hear about water pump installation is whether you should use water pump gasket sealer on the new pump. Here’s the correct answer
Unless the shop manual or water pump instructions tell you to use gasket sealer, do NOT use it. Here’s why.
Rubber O-rings and rubber seals on new water pumps are designed to be installed DRY unless otherwise stated in the installation instructions. Applying a gasket sealer or room temperature vulcanizing (RTV) sealant can actually cause an O-ring or rubber seal to leak because it interferes with the compression seal designed into the product.
Paper gaskets are designed to be installed DRY unless otherwise stated in the instructions. Shops and DIYers often apply RTV to the pump-to-gasket side in order to hold the gasket in place during installation. This is not the recommended procedure
but can be done IF you don’t over-apply the RTV. Excessive RTV that seeps into the contact area with the coolant will eventually break off and clog radiator and heater core passages, reducing engine cooling and heater operation. Water pump manufacturers do NOT recommend applying RTV or any gasket sealer unless specifically specified. If the gasket won’t stay in place, wet it with fresh coolant.
©, 2020 Rick Muscoplat