Attempting to R & R water pump 03 Maxima GLE. Brand new aftermarket pump, brand new Nissan seals. Installed and reinstalled pump several times. No matter what I do... Water added to the radiator pours out the weep holes. Adding water to the radiator in order to check for a good seal before buttoning everything up. No water should come out of weep hole if the pump is sealed properly into if housing on the inner timing cover... Correct? With every failed attempt, I remove the pump, inspect the seals, inspect the housing, and everything looks perfect. With this last attempt, I threaded the big nut on to the large idler pulley stud so that I could use a long screwdriver to push the pump and seal into position. Did require some Force... Indicating some resistance as the seal is compressed against it's inner timing cover housing. Then install the bolts to hold it in place. Same result. Water poured in the radiator comes out of the weep hole. If I pour the water in quickly... It comes out the upper whole as well as the lower one. The water doesn't trickle out. It comes out in a stream as if there is little to nothing interrupting it. Can anyone offer an explanation? I don't see how I can install the pump any better. Done it half a dozen times... So I'm pretty proficient at it by now. I have removed the AC compressor and alternator to verify where the water is coming from. Precisely from the to weep hole locations. I was actually able to get my eyeballs on the top one, with the thermostat housing removed. And yes... New gasket for the thermostat housing. Not leaking from there. Has anyone had this issue before? It doesn't seem to matter what I do... I can't get the pump to seal. Or rather... I can't get water poured in the radiator to not exit the weep holes after installing the new water pump. Sure like to figure this out. It's a beautiful car... Silver with Dove gray interior and about 150k.

 

Sounds like it’s time for another motor or for your current one to at least be pulled to see what the hell is going on.

 

so I redoubled my effort to diagnose the leak. Looks like it's coming from the area of the upper weep hole. You would think if the water pump wasn't sealed... Water poured in the radiator would start to dribble out of the lower weep hole first. Doesn't do that. Last time I pulled the pump, made sure that lower weep hole was clear. So maybe, it's not leaking from the upper hole, but rather the inner timing cover where it seals against the block to create a water jacket cavity the pump blades spins in... Is ruptured. the water is leaking down from there , trailing its way down the same path where the upper weep hole is located... Behind the thermostat housing. That's starting to look like the only plausible explanation for the results I am getting. Anyone ever experience and inner timing cover seal rupture before? My thinking is maybe the car got hot , pressurize the coolant system , could push it's way past the water pump seal... But could also rupture the inner timing cover seal as well. Whatever hole it's coming out is substantial. Because it just pours out. Not seeps out. thinking there is a way to verify this by removing the pump again, plugging the upper weep hole, reinstall the pump and pour water in the radiator again to see if it still leaks. I'll post the results. Any opinion about tearing the timing covers down and resealing them. Engine in the car, never done it before, not the best tools no, not the best mechanic, in a gravel driveway and not a shop.