Waterpump leaking!

Hey guys. I have a 1998 yz400f and it has a slight leak from the weep hole when I rev the engine. I have searched and have come to the conclusion that I need to replace the impeller shaft and two seals. My question is are these the same parts from a 2003 yz450f. The reason I ask is that in the OEM thumpertalk store, the oldest bike they list is the 2003. Thanks guys!

The TT store can get parts for your 400. Just email them with what parts you need.

Hey guys. I have a 1998 yz400f and it has a slight leak from the weep hole when I rev the engine. I have searched and have come to the conclusion that I need to replace the impeller shaft and two seals. My question is are these the same parts from a 2003 yz450f. The reason I ask is that in the OEM thumpertalk store, the oldest bike they list is the 2003. Thanks guys!

What is the weep hole? :thumbsup:

The weep hole is a little hole in the bottom of the water pump that tells you if coolant is passing by the first seal in the pump. This warns you before coolant is allowed to enter inside of the engine.

The weep hole is a little hole in the bottom of the water pump that tells you if coolant is passing by the first seal in the pump. This warns you before coolant is allowed to enter inside of the engine.
It actually is there to prevent fluid crossover, not just warn you about a leak. Because there is a space between the oil and coolant seals that is vented to the outside, either fluid that passes its own seal has no chance to reach the other seal.

Did a little more research and it turns out that the parts do have the same part #s.

It actually is there to prevent fluid crossover, not just warn you about a leak. Because there is a space between the oil and coolant seals that is vented to the outside, either fluid that passes its own seal has no chance to reach the other seal.

Thanks for the info. That is a really smart idea. Good job Yamaha :thumbsup:

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