In my quest to figure out my overheating problem, which was probably not an overheating problem, I decided to change out the water pump. The front pulley was a little wobbly so I thought that bad bearings may have been causing my water pump to not pump so well. So I purchased a new one and installed it, this is how it’s done!
Purchase a water pump for a Chevy 350. This is from a 1979 GM 350 without air conditioning, but will work from any model 350 from that era. I’m not sure if air would have made a difference…
The first thing that you will need to do is to drain the radiator fluid. Then you can loosen all the accessory brackets, so that you can remove the belts. I needed to loosen my alternator and the power steering pump. In the process I cleaned up any unnecessary basketry that was left over from the motor swap. There are some brackets that are connected to the water pump, those will need to be disconnected and removed before you can remove the actual pump.
I recommend removing the fan shroud as well. There are 7 10mm bolts that hold my shroud in place. They are easily removed and will make accessing the fan and other bolts much easier.
Remove the 5 Bolts Up Top
The two on the right
and the two on the left
The coolant hose that goes from the water pump to the heater core will need to be removed as well as its little nub. This nub does not come with the new pump.
Remove this hose
Take out the nub with a 7/8 wrench
Once the belts are off the water pump pulley, you will need to remove the pulley. The fan and pulley are both held in by bolts that are connected to the water pump shaft. Remove the 4 bolts and the fan and pulley should come right off. This is a little tricky and you may want to loosen them with the belts still attached to make it a little easier. I was able to do this with two opposing wrenches, but in hindsight leaving the belts connected until those bolts were loose would have probably been easier.
Pulley and fan removed, you can see the 4 bolt holes where they were bolted to.
The lower radiator hose will need to be disconnected from the water pump. This should be held on by a clamp of some sort, mine was held on by a screw clamp.
Remove the Lower Radiator hose
Once all this is removed, you will be able to start removing the water pump itself. The pump is held onto the block with four bolts, two on either side of the pump. Loosen them up and the pump should pop right off. There will be a little coolant spillage but it is nothing to worry about. While the pump is off, take a look at the passages and make sure they are as clear as possible. You don’t want any gook to impede the flow of coolant or to get stuck somewhere in the block.
2 bolts on the right
2 bolts on the left
To put the new pump on is the exact reverse of the above. The only thing to be careful with are the gaskets. I sprayed them with copper gasket seal and then mounted the pump to make sure that there were no leaks.
The finished product is below!