How do you change the water pump on a 2002 Chevy Silverado 4.8L?

Answer 1

here's how i did my 2003 6.0L. yours should be the same.

drain your radiator at least 1/2 way and catch the coolant. remove fan shrouding while radiator is draining. remove serpentine belt. remove hoses attached to water pump. unbolt water pump with fan attached and remove. be careful not to damage the back side of the radiator.

place pump/fan assembly on a bench. use a strap wrench on the pulley and a big wrench on the fan nut. remove fan from pump--it is left hand threaded and isn't on there very tight.

you will have to transfer the thermostat and its housing to the new water pump. use a scraper and/or scouring pad to clean the pump mating surface on the block. reinstall fan onto new pump--you don't have to tighten it that much. reinstall water pump--again be mindful of the backside of the radiator. torque to spec. reattach hoses.

refill radiator and start motor. check for leaks while you make sure that there is no air trapped in the cooling system. once you are sure there are no leaks reinstall fan shrouding.

as a side note: while you are at it you may as well flush your entire cooling system. i suggest doing that before you actually change the water pump as you will be flushing and draining the system anyway. once its cleaned out (using the old water pump) you can put the new one in and install new coolant.