Killed another water pump, less than 1500 miles on it

Salonika

Monterror Pilot
Searching for a coolant leak and it looks like I’ve narrowed it down to the last place I want to think of. The water pump. I just fried a pump in the fall, which was replaced and timing belt job done.
Now I am starting to suspect the reason my previous pump failed was more than a manufacturing defect or random occurrence…..the only source of coolant system contamination I can think of would be my heater core, which is original and still works, however I have gotten some of the signals it might be dying (fogging window and smelling coolant in cabin, but no leaks yet).
Any ideas on what could be killing my water pumps?
 

Michael Brown

You followed me, so now we're both lost
Water pump failures are usually either the gasket or the bearing in my experience. Both can be helped by purchasing quality units. The Dayco model I used didn't have a bearing fail, but the paper gasket barely lasted to the next timing service. I used Aisin parts this last time from RockAuto that should last a while.

Is it possible that the o-ring in the back of the water pump housing is failing? This sometimes gets overlooked during the timing job. I removed the intake to get to mine to fix.

1500 miles does seem like either a manufacturing defect or something went wrong on install. Hope you get the leak sorted out.
 
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Salonika

Monterror Pilot
All the stuff I am reading online points to contaminated coolant being top of the list. You can’t really overtighten the belt since it’s self adjusting with timing belt…..and the gasket is pretty easy to work with. I did replace the o-ring on the pipe that goes to the back of motor. Plus, no leaks at all down there for 1500 miles. Then boom, it starts leaking. Last pump was seized when I removed it in September 2021.
 

PacS14

Adventurer
Wow that sucks Big time. My Monty is leaking at the pump too, but I didn't replace that o-ring...smh I gotta do it in the spring now
 

CharlieNorth

Well-known member
Possibility on the Tbelt. If it is adjusted in a way that the hydraulic unit could bottom the piston out? Or something crazy as the pin left in place?
 

Salonika

Monterror Pilot
Possibility on the Tbelt. If it is adjusted in a way that the hydraulic unit could bottom the piston out? Or something crazy as the pin left in place?
I know for sure the pin was removed…..as for hydraulic issue you describe, I have no idea. Once I tear down to it I guess I could check timing belt tension somehow?
 

CharlieNorth

Well-known member
As long as you can find the pin hole the plunger would be in the proper extension. Just how contaminated could the coolant be after a service, granted I could be overlooking many options.

Can you flush the system well before breaking it down?

How about the little vent hoses from the front of the heads? I had one of them fail on a fresh build while the system was still on water only. Finally at one point I saw steam from under the right belt cover, Found a tiny hose was bad.
Actually not sure if those are on DOHC only.
 

Salonika

Monterror Pilot
Out of curiosity,
is the leak from the belt cover or out of the valley on the back?
Valley is dry as a bone. No coolant leaks visible topside. Underneath however drips and coolant all over, which makes me think it can only be from the water pump. I just bought a pressure tester so I can try and make it leak without running engine. Based on this I really can’t see it being anything else unfortunately.
 

CharlieNorth

Well-known member
If I had two good legs I would jump too the conclusion of a gasket issue. Make sure the gaskets to the block are factory MLS type.
 
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