cant figure out how it all works, the pump fin is constantly connected to the gear that turns, so how does the mechanicle seal work? I thought the pump would turn when the water gets hot, but seems to turn all the time. really confused!

 

The water pump is driven by the crank shaft. So if the engine is running the the water pump shaft is turning the impeller. that moves the water around the cylinder and through the radiator. Very simple process.

 

Yes he is exactly right

 

why does it have a mechanicle seal, I thought it was so it would open and close like a car so that the water has time to sit and cool off in the radiator???? otherwise it would be just a regular seal right??

 

It does not work like a car there is no thermostat. The heat being disapated is not that great constantly moving water around the cylinder is plenty. The mechanical seal is needed to sepeate the oil in the crank case from the coolant. Thats what the ceramic seal on the back of the impeller is doing and why you need a new washer for the impeller every time or it will leak.

 

hmmm.....My water pump is leaking out the weap hole. Maybe it's because of this. I'm also having a hell of a time tuning it. Maybe the water is getting into the crankcase as well. It had a bad head gasket and the sleeve is a whole other story. I replaced the whole cylinder. I figured when I replaced the head gasket it would stop pressurizing the coolant system so much and it would stop. I know my water pump is moving water so it can't be bad, but after hearing this I've got a new idea.