Water Pump Turns Into A Can Of Worms

Hello Gray Ghost Fans!

A break in the weather made for a good day to be in the garage. I've been wanting to do the water pump replacement for quite a while.  Here is the link to the whole sad story on why I needed to replace the water pump.  However, I decided to wait until I was closer to doing the engine swap.  Now, I'm getting close.  So to the garage I went.

Taking the water pump off was pretty straightforward.  First, you have to drain the coolant.  That's pretty easy to do with the petcock on the radiator.  Due to the danger of animals getting into the old coolant, I always try to be careful and not spill any.  I collected the old coolant and have it in plastic jugs.  Tomorrow I'll take it to the recycling center at the dump.  So far, so good, right.  Right.  Too bad it never ends when it's going so well.

Anyway, all the coolant that would drain out was out and collected.  Time to get to that pump.  First, though, I had to get the alternator out of the way.  The bolt that holds one of the alternator brackets also holds the water pump in place.  So, I loosened the alternator, removed that bolt and swung the alternator out of the way.  Next, the other 3 bolts that hold the water pump in place.

After 66 years, that old water pump was really stuck in place.  A couple of blows with the persuader and it started to come loose.  Then it happened....  The water pump came loose and all of the coolant that hadn't drained out flooded out, right onto the garage floor.  A quick panic later and I'm crawling around mopping up the mess.  Holy cow!  A whole roll of paper towels later...and it's cleaned up.  Time to move onto the work.

Before I took the pump out, I removed the old heater hose that had been looped between the water pump and the thermostat housing.  The hose barbs that were attached to the water pump and the thermostat housing were crusty.  So, I took them both off and gave them as good of a cleaning as possible.  When the barbs were out, I noticed something sticking out of the thermostat housing.  It looked like this:

After disassembling the housing, I removed the part.  It looked like this:

I have no idea what it is or what it is supposed to do.  All I do know is that it isn't a GM part, so out it goes.

With the housing apart, it was time to replace the old thermostat.  The old one looked like this:

Pretty crusty!  Believe it or not, the black area surrounding the old thermostat is the old gasket...or what is left of it.  A little scraping and new thermostat and gasket and we're looking up!  It looked like this:

You can see a tiny bit of RTV under the gasket.  Just a thin layer to make sure it stays leak proof.  I then reinstalled the old hose barb back into the housing and added the upper part of the housing.  Once it was all back together, it looked like this:

I know what you're thinking.  You cleaned what?!?  Trust me, I cleaned the heck out of it.  In this view, you can see exactly where that water pump needs to go.  You can also get an idea of just how much coolant came pouring out when it flooded! 

With the thermostat rebuilt, it was time to put that new water pump in place.  Before installing it onto the engine, I put the other heater hose barb onto the new pump.  The pump had a second opening, which I didn't need, so I installed the plug that came with the pump.  Once it was on the engine, it looked pretty good:

Remember the can of worms in the title?  Yeah, well this project just keeps giving and giving.  Notice the pulley in the pic?  Yeah, so what?  Well, I'll tell you what.  This engine originally came in a car, not a truck.  The original water pump was a "long shaft" water pump.  Those don't fit in the truck without some modification to either the pump or the radiator.  This pump is a modified pump and is a "short shaft" pump.  So far, so good.  The problem is that the diameter of the pulley is smaller than the original.  So... I need a new fan belt.  That one I did not see coming.  So tomorrow I'll be heading to the auto parts store to get some heater hose and a new fan belt.  It seems as though I'll have to do some math to figure out the difference between the large diameter and small diameter pulleys and how much smaller my new fan belt should be.  My old nemesis, math...( (2 x radius of large diameter pulley) - ( 2 x radius of small diameter pulley) ) = number of inches less of fan belt required (I think).

So, a rambling post.  Sometimes it's hard for me to be succinct.  Anyway, one more link in the chain is complete.  That much closer to doing the engine swap, so it's all good.