How hard is it to change the water pump and thermostat on a 1974 Chevy Nova V8 350?

Answer 1

In short it's fairly strait forward to replace the thermostat and the water pump on any Chevy 350. First off you must drain the radiator. To do this simply turn the "petcock" located either on the bottom left or right hand side facing the engine on the radiator. Note.....lefty loosey righty tighty doesnt apply in this case as the petcock will turn to the right in order to drain the radiator. Take the cap off to vent but be sure the radiator is NOT HOT. Otherwise, allow it to cool before removing the cap. You can get a pretty nasty burn. Once the radiator is empty remove the TOP radiator hose from the engine. This should only involve removing a hose clamp and then gently twisting the hose until it breaks free from the intake manifold. Once the radiator hose is removed from the engine you are about 2 inches from the thermostat. It's just under where you took the hose off of the engine. Two blots on either side of the thermostat housing will free the housing and reveal the thermostat. When you buy a new one make sure you also get a new gasket. Clean the area thoroughly of the old gasket. (There may be another smaller diameter hose attached to the thermostat housing. If so simply remove it for the installation then reassemble once the thermostat housing is back in place.Use caution to not drop anything into the engine such as pieces of the old gasket. If necessary cover the exposed hole with a clean rag to help prevent contaminating the cooling system. Reverse the dissasembly process to reinstall. It helps to use an rtv blue sealer to keep the gasket in place during the reassembly. Make sure to note the location of the thermostat Then install one of the bolts into the water pump and lower it into place with one hand while ligning up the bolt with the appropriate hole. Once you have one bolt started install another bolt in the opposite side and hand tighten them to hold the water pump in place. Install the other two bolts then tighten in an alrernating pattern. (top left, bottom right, top right, bottom left) Do so in multiple passes as to help promote a good seal on the gaskets. Once tight you can then star the reassembly in reverse of how you removed everything. Last off first on. Once you have everything installed be sure to close the radiator petcock and then refill the radiator. It will take some time to drain into the engine so you will have to repeat the filling process a number of times before the system is purged of all air. Once you have at least 2 gallons of 50/50 antifreeze mix in the radiator you can then start the engine for short periods with the radiator cap off to help "burp" the cooling system of excess air. Once full, run the engine up to normal operating temprature with the radiator cap on. Usually about 15-20 minutes will do the trick. Then check for leaks around all the hoses and fittings you removed and reinstalled. If there are leaks then retighten.