Water pump coolant seal

I have coolant leaking out of the weep hole on my 2007 WR450. I understand from doing a search on here that this is most likely the water pump coolant seal that needs replacing. I have some questions about this and wondered if someone could help.


1. My bike appears to have only done approximately 530 miles although I have no way of checking this. If my bike has only done this low mileage is it still possible the seal could have gone from just wear and tear?


2. What makes the seal stop sealing, is it the miles/hours or is it heat build up and time or something else?


3. Is it okay to just replace the coolant seal and leave the bearing and oil seal in place, I don't really want to have to start taking those out if I don't have to in case something gets damaged in the process?



Mine seem to fail after sitting over winter

Just put my third one in, after it leaked again at the beginning of the year when I start using it after the winter lay up. Couldn't be bothered to change for the third time so kept riding it to see if it would fix itself, but it didn't!


1) Its a time thing rather than mileage thing normally

2) The seal is worn and hence leaks. High milage bikes can have a worn impeller shaft but yours won't at 530miles

3) Yes, just replace the seal.

Drain coolant, remove right side clutch casing. Remove water pump cover to expose impeller. Hold impellar shaft on the big flats across the shft near the impeller (do not hold using the flats at the end of the shft that fit into the balancer shaft). Undo impeller. Lever out seal. Fit new seal, noting the way the worn out seal is fitted. Refit shaft and torque up impeller. Refit casing to the engine using a new gasket (you will need to wiggle the shaft about so its drive flats fit into the balance shaft recess. Refit water pump cover. Fill with coolant and away you go

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