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tmc55

water pump impeller shaft

11 posts in this topic

hello everybody i have a 2000 426f do i have to drain the oil out of the bike to change the seals,bearings,and shaft because i want to do the job right the first time around thanks any info would be great thank you.

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Yes, you will need to drain it. Part of the job is to disconnect the feed line at the case cover, which will drain the frame for you, whether you like it or not.

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hey gray, ive always layed my bike down on its left side, put the handle bar on my bike stand, and only drained coolant, before tipping over of coarse, let it sit for a half hour or so to get all the oil into the other side, and done it that way.

is there a problem doing it this way ?

actually forget it, im not sure that i did manage to get it all apart like this, i know i lay it down on the right side to do the stator, and i know ive worked on the clutch this way, but cant remember if ive done the water pump shaft.

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Laying the bike over, especially if you run it for a minute a half hour before you work on it, will work fine for accessing the stator, and the clutch, for that matter, but as soon as you have to remove the right side cover, the oil system gets opened up, and the tank has to be drained.

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Hey GrayRacer I'm just kinda curious as to why you think the impeller shaft needs to be replaced.

you will probably find the shaft needs replacing because of a small groove worn into it.

Does the grove damage something? Also what is wrong with just replacing just the oil seal 1? That is the one that is leaking ...

I'm not attacking you! Don't take it that way I'm just curious as to why you believe it should be done that way.

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Generally, the oil seal on the impeller shaft almost never fails. It's usually the coolant seal. Coolant is a better lubricant than water, but falls far short of oil in that capacity, and as the seal wears, it wears a corresponding groove in the shaft somewhat faster than if it were running in oil. The trouble with this groove is this: as the shaft spins, it also moves around a bit off of its axis, and the seal lip has to be able to follow that movement and maintain the seal against the shaft. In order to do this, because of the angle at which the lip contacts the shaft, it must be able to move freely along the length of the shaft a small amount. If the groove is deep enough, it tends to trap the seal lip and prevent it from moving along the shaft.

I have found that in more than half the cases of leaking impeller coolant seals I've seen, the shaft wear has been bad enough that I would not recommend reusing it.

And that's why I say that. :lol:

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Ahh thank you for explaining that. When I first read what you posted, I thought you were talking about the impeller rubbing against the shaft which confused me because I didn't see how it could. I see that what you are saying now, the seal itself rubs a grove onto the shaft that it is sealing. Thank you that makes sense to me now.

I was recently having this problem and just ordered the coolant seal (In the manual it refers to it as oil seal 1 and oil seal 2). The wear on the shaft seems very minimal and what I would say in fairly good condition. Thanks for the pointer!

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if it's VERY minimal (can't catch a finger nail on it yet or just barely feel it), you can use emery cloth to smooth it out, but only once or the diameter of the shaft will change too much for future seal replacements to work well.

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