I had my radiator go out on me and it was serious. I was really heartbroken over this. So while it was in the shop with the heater core, I began to tear into replacing the thermostat, radiator hoses, and heater hoses, then I looked into the water pump connections for the heater hoses and the water pump was pretty ugly with dirt and grime. So I pulled it. I had new gaskets for it anyway, Why not? Right? I pulled the pump, While at looking the rest of the water pump, and looked into the cooling ports and it was all rusty and had a calcium build-up too. So I cleaned up the engine itself of all the gasket silicone maker left on it from whoever replaced the water pump before I bought it.
So, I use my paint scraper, for me, this works great! Try not to get any in the engine, you can use masking tape over the holes or you can also stuff a clean cloth in the water ports ( holes). You will want to do this anyway if you’re replacing the pump, or what I am doing, with the pump being off a long period of time. Okay, back to the water pump. I cleaned it with a de-greaser and a couple of different scrub brushes, for all the hard to get to places that were hard to clean, then rinsed it and left it to air dry. Then I pulled out the hose tube ( that goes to the heater core) from the pump VERY CAREFULLY. So be careful with yours. Mine came out pretty nicely.
So after this, I take a good look at the backplate & gasket ( Where the propeller cover is located) and it’s in great shape. So now we are looking at the bearings or the “feeling” them, if they are loose or how the shaft feels while turning it by hand. Mine was perfect! No play in them, the propeller blade moves freely, no binding or grinding from being bent, it’s never been changed since I have owned him. (My truck) So this pump is great to be used on the truck again! First, start with a coned-headed grinder wheel attachment that works on any drill to clean out those water ports that are filled with all that rust and calcium. Now I didn’t go in that far and grind out any steel from the pump walls. Just enough to clean out the rust and junk.
So then I got some round wire brushes to attach to my drill to also clean out the heater tubes and the threads. It worked very nicely for these holes. You may want to use a reversible drill, I had to pull out my cordless drill and it took a little longer but it worked out.