If you notice coolant leaking or your engine overheating check to see if the leaks are coming from around your water pump gasket. Sensor safe noncorrosive rtv silicone gasket material formulated specifically for water pumps and thermostat housings.

Permatex Water Pump Gasket Sealer Instructions
Water pump gasket sealant. A non corrosive sensor safe rtv silicone gasket material formulated specifically for water pumps and thermostat housings. Over time the gasket can wear out which can lead to coolant leaks. It can also be used to fill small imperfections in the metal surfaces promoting a more positive seal. If your new pump comes with a seal make sure its in impeccable condition before installing it. A thin coat of good silicone rtv is what id use for a gasket. 2 is great for any bolts that go into watercoolant and need to be sealedbtw.
You can use the engine silicone sealant on both sides of the gasket. When changing a water pump replace all old gaskets and seals with new ones. A noncorrosive sensor safe rtv silicone gasket material formulated specifically for water pumps and thermostat housings. Copper gasket sealant available both in brushable and in aerosol forms copper gasket sealer is fast drying and the metal content suspended within the sealant helps to dissipate heat and promote even heat transfer between the mating surfaces. Superior adhesion and flexibility. 65f to 500f 54c to 260c intermittent.
Dont apply sealant to an o ring or a dry seal. But it is rather tough to remove in the future. Highest water glycol resistance available in an rtv silicone. You dont have to goop it on use it like a glue to keep it in place. Can be used as a gasket maker or dressing. Highest water glycol resistance available in an rtv silicone.
Best thing to do is use it to attach it to the pump first and then make the same small bead on the other side of the gasket but let it sit for about 10 15 minutes before you put it on. K seal coolant leak repair st5501 8oz multi purpose formula stops leaks in the radiator head gasket block water pump casing heater core and freeze plug pour and go trade trusted stop leak. Let it cure a few minutes before assembly and a few hours at least in warm weather before filling the system. The water pump gasket seals your water pump to the engine block. Highest water glycol resistance available in an rtv silicone. Some seals are so thin you could easily damage them when you rip off the packaging.