I will be replacing the water pump later this week. I have been tracing an intermittent leak recently. This morning I found the culprit. The heater tube/pump interface is leaking. It is not the heater hose, but the tube where the hose connects. Either the pressed connection is leaking or the tube itself has fatigued. Anyway it appears to be a straight forward job. I read in our that the bolts are aluminum? https://blazerforum.com/forum/articl...-thread-24597/ I'd be surprised if this was the case.


Assuming they are steel, what is the favored thread sealant for the bolts?

 

The bolts are indeed steel, not aluminum. 5/16" if I'm not mistaken. This stuff works fine: Permatex High-Temperature Thread Sealant (.2 oz) 59214: Advance Auto Parts

Rent the fan clutch tool kit, you'll be glad you did. When the alternator and compressor are out of the way, check for lower intake manifold gasket leaks.

 

I got the note that the pump will be here tomorrow. So I spent some quality time in that garage pulling the pump off. Indeed, the bolts are steel. a 9/16 socket fit. I don't know what's up with the write up? Fan came out fairly well. I made a wrench out of some 1/4" steel plate and used a hammer to "impact" it loose. It sounds bad but have done this in the past.


Thanks for the heads up on the thread sealant. I'll have to pick some up.

 

That job's done. It was pretty simple, really. Now I need to give it just a few heat cycles to expel any captured air.

 

Is there any trick to getting the water pump gaskets to seal? I replaced my pump about two weeks ago. A week after that the pass side seal started leaking. I replaced that and I noticed today its leaking again. I dont know what im doing wrong but this is very frustrating. Ive been using a gasket sealer specified for water pump gaskets. I tighten the bolts down to 35 ft/lbs. Im lost at what to do.

 

The water pump, and the block surfaces, have to be clean before installing the pump. No sealer is needed or recommended.

 

Yeah I cleaned the surfaces with a razor blade and sand paper. But I did use sealant. Maybe thats my issue. I really dont wanna have to take the dang thing back off to replace the seals a third time but looks like im gonna have to.

 

Is it leaking from the gasket or from the beneath the bolt heads? Maybe you didn't get the threads in the block cleaned, dried and then sealed. Or maybe you gat a poorly machined water pump? I had no particular problems.

 

So I figured out what it was. The passenger side top bolt had come loose just a little bit. I tightened it back down and re-filled the reservoir and went for a drive...no leaks. Im gonna let it cool down then pull that bolt out and put some threadlocker on it. Does this sound reasonable or is there something else/different I should do?

 

That should do it.