Heater hose routing

[bigdon-70blazer]

On the 1970 Blazer, 350 V-8, automatic, 4WD I am trying to reinstall the heater hoses. Wouldn't you know I have pics of alot of stuff during the breakdown, but not this! Who knew! I have a nub sticking out of the top passenger side of the intake manifold, and two nubs on the water pump. Now since I did not do the engine work I can't tell what happened. My buddy did replace the water pump, I have the old one to reference, he removed the nipples and mirrored what he saw on the original one and replaced them on the new pump. I have 2 nipples on the pump. One at the top, a brass 90 degree turn type nipple and a black nipple on the side of the pump. I don't know how to edit to make pointers on my pics but I can pass anesthesia in the OR, go figure! I do not have a/c and need to know where these hoses attach. Do I have one too many nipples, (that just sounds wrong)? Where do I route this stuff? Any help or pics would be helpful. I searched the forum but did not find exactly what I needed. Also, I have a fitting on the oilpan that had a black rubber hose attached on teardown, what was that? Help a brother out so I can stop sitting on a chair looking at the blazer and get back to work on it!

[jaros44sr]

Don't take this as your final answer, because I have never had that exact setup...but if the nipples on the water pump are 5/8" and 3/4" that would tell 'me' they go to the heater core. Then just plug the intake, seems like a clean setup if you could go this route

[tcb-1]

now I see what your talking about.

the top outlet does not look factory. the galvanized pipe coupling mated to the bronze 90 degree nipple just doesn't look right.

as I said last night, my water pump outlet has the side discharge and the same adapter nipple as yours.

I wonder if it had anything to do with the fact that the p.o. had that K5 set up to run on propane??

I'd throw a nice bronze pipe plug on the top pump outlet and roll.


by the way, nice GM heater hoses! you need to pick up the original type hose clamps..... Classic Enterprises $20

[jaros44sr]

Originally Posted by tcb-1

now I see what your talking about.

the top outlet does not look factory. the galvanized pipe coupling mated to the bronze 90 degree nipple just doesn't look right.

as I said last night, my water pump outlet has the side discharge and the same adapter nipple as yours.

I wonder if it had anything to do with the fact that the p.o. had that K5 set up to run on propane??

I'd throw a nice bronze pipe plug on the top pump outlet and roll.


by the way, nice GM heater hoses! you need to pick up the original type hose clamps..... Classic Enterprises $20

Well propane changes my anwer, IIRC there should be a regulater that was mounted somewhere, and that is why he has an extra hose to the water jackets on the block.

Thanks for pointing out the GM hoses, missed that

[bigdon-70blazer]

Doug, I did not ever say thatt the po used propane on it so that was never an issue. The fitting on top, it is there on the pics after we removed the engine along with the fitting in the middle of the water pump. The heater core was hooked up on the fitting top of manifold. And any idea what that hose is hanging on the bottom of the engine?

[bigdon-70blazer]

jaros44sr, po did not use propane so don't let that taint your thinking. Please help me figure this out. Driving me crazy!

[jaros44sr]

Originally Posted by bigdon-70blazer

jaros44sr, po did not use propane so don't let that taint your thinking. Please help me figure this out. Driving me crazy!

Can you measure the necks of the fittings? should be 5/8 or 3/4

[bigdon-70blazer]

I HAVE HAD A REVELATION!!!!! I was standing around looking at the engine trying to think, think, think. I dragged out my old hoses because I saved all stuff from the blazer before the rebuild, you know Foghorn Leghorn..."Fortunately I keep ma feathers numbered for just such an emergency!" I have a lot of useless crap that will get thrown out after the build but I cannot tell you the number of times the old stuff has provided me clues to what questions I had at the time. Got out the old hoses and could even tell where they had been based on the marks made by the fittings, sounds goofy but you all have done it and know what I mean. I then remembered that this blazer had an aftermarket engine block warmer! THAT'S IT! Explains the hose at bottom of engine and fitting at top of pump. So I guess my next question is I guess I just seal both with brass fittings, right? I mean the top of the pump is kinda obvious but the block fitting... Any ideas.. Wow I do love this forum!

[1949gmc]

I was actually thinking engine block heater, but didn't get the chance to say it. Make sure the holes on each side of the block are plugged and remove/plug the fitting on the top of the water pump (brass will work fine for each of these... or steel...doesn't matter). Use the intake fitting and the lower water pump fitting and you've got this part of your build finished.

[tcb-1]

crapola, I fouled that one up. I just remembered the tank that was mounted to the frame rail but that was for air-on-the-go, NOT propane.

and yes, that's block heater tubing. I had one that came out of the block in the same exact position. however mine teed off of the existing line out of the water pump. Looks like your water pump was actually modified to include a second outlet. I think it was a dealer or aftermarket install.

I simply removed the fitting on the side of the block and installed a pipe plug with a small amount of loc-tite. I'd do the same with the fitting on the top of the water pump.

or fill the radiator with desalinized water, put a tap in line on the hose from the water pump to the block and have water for your coffee......

or maybe not.

[bigdon-70blazer]

Coffee on the go for all of your enemies...