How do you change a water pump in a 1978 Oldsmobile v-8?

Answer 1

If your car is anything like my old '77 Buick Century Special its not terribly complicated, just a bit time consuming.

First, I'm presuming that the pump hasn't been changed in some time so you'll need plenty of Liquid Wrench or WD 40 to loosen those stubborn bolts both on the fan AND the pump housing. Spray liberally and let it sit for about 30 minutes to an hour. While the oil is working, drain the coolant out of the system into a bucket or other container by either opening the radiator petcock valve (if your car has one) or by removing the rad hose from the bottom connection port of the rad. Remove and/or loosen the appropriate belt(s).

Bear in mind that the fans on cars are "reverse threaded" so that they don't go spinning off into the radiator. Youll need 2 pairs of channel lock pliers or Vice Grips for this - one to grip the pump shaft and keep it immobile and the other to loosen and remove the fan blade assembly by rotating the fan assembly in a CLOCKWISE direction. Depending on how frozen or rusted the fan assembly is you might need a helper and a lever to get it to start breaking loose.

Once the fan blade is out of the way it gets a heck of a lot easier, because all that is remaining is pulling the pump pulley assembly and removing the bolts holding the old pump in place and seating the new pump with a fresh bead of liquid gasket. Make sure you don't mix the bolts up, though - they have to go back into the same holes they came out of. Let the liquid gasket sealant cure according to package instructions (usually 1-3 hours).

While the sealant is curing, reattach / reseat the coolant pump pulley and belt, reattach the fan blade assembly, and reattach the lower coolant hose if it was disconnected.

After sufficient time has passed, refill the system and turn it over to circulate for a few minutes and check for leaks.

*** Money saving tip: If the coolant you drained still has a bright green appearance and doesn't have a lot of brownish-colored deposits in it you can re-use it instead of buying brand new coolant.