1985 K100RS oil/water pump seals a second time!

Back on Dec 29th I started a thread about the happenstance find of the decapitated impeller nut while setting out to upgrade the impeller style and all associated components that go with that. I tapped the new seals in with sockets and then used the tool from Motorworks (followed their instructions to the letter) to pull the impeller shaft through the water pump seal after first press-fitting it in to a stop point with my hands. Pretty straight forward really and not anything some of you guys haven't already been through without incident. It all went back together without incident and the feel of the components felt right while spinning it.

After installation of the pump and refilling with coolant I had the presence of mind to put a pan underneath just in case. The bike wasn't and isn't in a state to be started. A couple of days later I noticed a drip of coolant in the pan. I stuck the blade of a small screw driver into the weep hole and a little coolant ran down the shaft. Clearly there was leakage into the cavity until enough accumulated for a drop or two to set themselves free. I was seeing a drop every 3 days or so.

I pulled it all apart again earlier today. The water pump seal looked undamaged and perfectly fine. As it didn't want to come out willingly I decided to pack it in before I got too irritated. At least I had the presence of mind to buy a second pair of seals when I bought all the components initially.

Honestly, I have no idea how I could have screwed this up, but maybe someone here has some advice. I'm hoping I just had a seal that was defective in some way and that it wasn't something that I caused unknowingly.

Tom

Hello,

I'm a decent mechanic having done all my maintenance on my bikes. However, when it comes to the oil/water pump seal I have the dealer install the seals. I don't remember exactly why. I'll remove the pump, but I take it to the dealer and have them install the seals.

Regards,

Richard in Commerce Township, MI

Perhaps a bit of "running in" would help it seal. Get the engine up to operating temperature and let the system pressure against the seal help it do it's job. I don't know if this would work, but what have you got to lose?

Frank

oil/water pump seals

When installing new seals do not tap them in as you would with normal seals but draw them in SLOWLY with shaft and spacer. A small amount of lube on the seal helps.

Whoa !
Haven’t even run the bike yet ?

51797

Perhaps a bit of "running in"

Click to expand...

Very sound advice !

I would run several hundred miles before I would judge the successful repair of these seals.

I have never heard of catastrophic failure of these seals.

The saying “It’s not over till the Fat Lady sings” requires that she sings.
Run the engine; (is my Two Cents worth also).


Charlie

Agreed.