How do i replace the gasket on my waterpump on my 92 Sierra?

 

Are you sure it's the gasket, and not the pump itself? If it looks like its leaking from the bottom of the pump, it's probably the pump, unless its been apart recently.

 

IMO I'd replace the water pump if you're going to go as far as do the gasket seeing its an older truck.. any ways installing a water pump is fairly simple in that truck. First off take the radiator shroud (plastic bordering the radiator and the fan) so you can get space to work. then the fan must be removed which is 4 nuts usually bolted on the studs of the water pump itself.. once the water pump is in view their is usually 4 bolts in the corners of the water pump bolting it to the block which obviously you want to take out in order to remove it. Do you have AC? if you do their is an aluminum hose fitting that threads in front of the water pump, I suggest you just get a new hose fitting in my experience the old fittings break inside the water pump during the process of removal (especially in older trucks) you can get the heater hose fitting from the dealership for cheap. The gasket is obviously located between the block of the motor and the water pump, make sure to easily clean the old gasket off with a gasket scraper. Installation is the same as removal.. Good Luck!