It fills the gap between the engine and the water pump in your vehicle. Dont put it on too thick just enough to hold the gasket in place on the block or on the pump.

How To Replace A Water Pump Advance Auto Parts
Water pump gasket install. An improper seating damaged seal or misaligned gasket can mean the water pump is not operating efficiently or worse is under undue stress from misalignment. If you flush the cooling system with a water pump attached use the old water pump and not the new one to prevent impurities from contaminating the new pump. Do not force the pump on by striking the pump shaft. In the past it was not uncommon to coat a gasket with sealers or adhesives before installing it. When changing a water pump replace all old gaskets and seals with new ones. Use the gasket and put the gasket maker on either side of it.
Then apply a dab of rtv sealant to the bolts and install the bolts finger tight to hold your new water pump in place. Old gaskets and seals should be replaced by new ones. The water pump gasket is a simple sheet comprised of gasket paper rubber silicone metal felt and fiberglass or plastic polymer. Proper installation is the key to long service life as installation practices are changing rapidly as gasket designs advance. Put an even bead of sealant along the edge of the part but dont use too much sealant. Double check that all the bolts are in place and in their.
Position the new pump straight onto the mounting surface of the engine block. Dont apply sealant to an o ring or a dry seal. Only apply sealant if specifically recommended by the vehicle manufacturer. Should leave you in good stead. Make sure the bolt holes align. Today fel pro offers many gasket designs with advanced leak sealing technologies built directly into the gasket.
Install the new water pump. It will do the same job and work just as well. Carefully follow installation instructions. Without the gasket the coolant flowing between the water pump and the engine block would undoubtedly leak out.