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Kuznik

Coolant leaking form pump drain?

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I noticed I had some coolant leaking, and upon a good look it seems to be coming from a small drain hole at the bottom of the pump. Why is it doing this and is this a problem, I do ride on the street and I assume it could be happening because I am idling at a light? and getting to hot but we do have a overflow bottle.

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Hey man im not sure about your problem. But i noticed your up here in B.C. . U got your bike motarded or you got dirt setup still. i got an 01 426 plated right now its just set for dirt for now till i get some wheels.

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that hole is is a drain hole. When the waterpump seal fails, water leaks out of that hole. You will need to replace the water pump shaft (more than likely), the inner seal (oil) and outer seal (water). It has nothing to do with the temperature of the engine.

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I noticed I had some coolant leaking, and upon a good look it seems to be coming from a small drain hole at the bottom of the pump. Why is it doing this and is this a problem, I do ride on the street and I assume it could be happening because I am idling at a light? and getting to hot but we do have a overflow bottle.

Yes, the hole is a drain to allow coolant/oil to leak out if a seal fails. The water pump is driven by a shaft from the engine which has an oil seal, then it goes into the water pump which has a seal. This drain hole is located in between the 2 seals. This is by design to releive the leak to the ground instead of water in the oil or visa versa. Mine did it at 90 miles,. second ride after buying it brand new. I replaced the water pump seal and so far, so good. I have about 250 miles on it now. Seems everyone in here had the same trouble early on. Kinda like fork seals. :):)

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Thanks guys,

Yamadirt, yes I have it motarded. But I do still play in the dirt easy transformation, as it is a basic swap of parts. Takes like an hour to do.

Also have it plated as not enough track time to keep a person happy. I don't know how to post pics on this site but if you check out supermoto junkie, this is a link wit a pic.

http://www.supermotojunkie.com/showthread.php?t=5257 this is it.

Anyway know another guy with a 426 plated and he races as well. Where about are you?

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ohh any reason why it happens or just the nature of the beast with these things.

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yeah, just the nature of the beast. I did mine last year. Just make sure you keep coolant in you engine, not just water.

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About how much does this repair cost? I'm going to look at a street legal '02 WR426 today. The guy is asking $4200, but he said there is an "unlocatable coolant leak". It would be nice to have some bargaining leverage :applause:

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$62. cost for parts to repair and about 1 hour. New pump shaft, new oil seal , new water seal. New shaft is needed because the water seal will cut a groove in the shaft and the new seal will not work on a grooved shaft! :applause:

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A little secret to avoid replacing the shaft and save some money. When you drive the new seal in, dont drive it in quite as deep as the original one. This will allow the new seal to ride on a fresh spot on the shaft. :applause::eek:

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