Water pumps(new and old) keep leaking at high RPM and boost, what's the deal? I've now installed a new factory pump and it's doing the same as the other 2 replacement aftermarket pumps. Do I need a bypass for the water pressure?

 

Wow, Nobody else with this problem? Could it be my T-stat even though temps seem to be in check? Flow?

 

How much boost are you running?

 

Tom, something else besides the water pump is pressurizing the coolant system.

... assuming the square O-ring is in good shape and the mating surface is clean.

 

The o-rings have been in great shape, but I was concerned that they were cut too deep into the pump housing(the groove) on the aftermarket pumps. My head was o-ringed and Zach Hamilton can't see any reason to think the HG is leaking, he actually wants to cut down the blades on the water pump(he says they have to do that all the time on high HP engines to avoid over-pressurizing the coolant system). I'm only running 50psi max on these WOT runs that I'm getting the leakage on. It never leaks at 3/4 throttle or WOT bursts, it only happens on a long WOT run, at least a mile or so of WOT. What do you think???

 

I'm not a fan of clipping the impeller fins, since it significantly reduces system pressure (and cooling potential) at lower RPMs, where the engine is likely to spend most of it's life... I prefer to manage coolant overpressure with a bypass-type modification.

Can you determine exactly where the coolant is leaking around the pump? Is it the weep hole, or all around the mating flange? It can be difficult to accurately ascertain, since the fan blows the fluid around pretty well!

I would narrow the problem down to RPM or boost-related; a simple 3500RPM (75psi) excursion for a few seconds while parked should answer the question.

 

SO I can't hurt the engine in park w/ no load?

 

CTDs can run 24-7 at rated speed...

though you might have to "nut up" to stick your head close enough to watch for it at that speed (motor sure sounds like it means business!)

 

See if he can borrow Madhats helmet for that job

 

There is a kit for the head that is a bypass to relieve pressure in the head for guys running the high rpms. It is called an EEP.I will try to find the post and put it here. Update: I found it in my private messages, I will pm you with the info.