I have a problem with water/oil pump. My K100 is from 1983 so the old shape of gear was with the nut on the shaft instead o bolt. So what was precictable it was corroded and I broke it. I bought another pump but things inside looks different like number of tooths and also slightly different housing shape.The question is f both pumps on the pics are interchangable??? Also I have aproblem with removing the shaft (in "new" pump) from water sealant and housing, I punch with hammer with force but affraid to use bigger force not to brake something. Is that possible the shaft seizure inside sealant or rosted? If that is a matter of the higher accesive force..no problem, just wanted to be sure.

That's a K1100 pump, it will fit and work perfectly on a K100. I have one on my RT for about 10 years.

Thanks for info. What about water sealant, are they similar in late K100 and K1100? Also I do not know why I can not pull out the gear, even when hit with the hammer. Is seizured or I did not unscrew something???

PiotrK100 wrote:Thanks for info. What about water sealant, are they similar in late K100 and K1100? Also I do not know why I can not pull out the gear, even when hit with the hammer. Is seizured or I did not unscrew something???

Does it rotate? If so it's not seized.

It is rotate, but can not pull out!!!! Must be the reason of some kind and I do not know what. MAybe there is something in that housing that must be unscrewed???

I recently rebuilt the water/oil pump on my K1100LT.  The shaft came out without much effort.  I think there must be rust/corrosion that is causing your problem.  I would just "get a bigger hammer" and drive it out.

PiotrK100 wrote:It is rotate, but can not pull out!!!! Must be the reason of some kind and I do not know what. MAybe there is something in that housing that must be unscrewed???

Nothing in the housing to hold the shaft except the old seal. I have ( in the past) put the pump in a big vice, with some wood to save the mating surface of the housing and enough space to squeeze the shaft out a little.

If you don't have a big vice use some timber blocks on the face and a piece to hit on the back. once dislodged it should come easily.

good luck

could it be, that he has the new ceramic type water seal already installed ?

advice would be not to try to change it ...as it must be destroyed to be removed

just a heads up