Hi again,

So I rode the k100 about 3 miles to work today, ran fine, everything was fine, etc etc.. I noticed, when I got off work and walked back to my bike, that a good amount of coolant had puddled underneath the engine. The coolant reservoir was also a little bit on the low side. It's never leaked coolant in the 3 months that I've owned it. I also managed to find exactly where it's coming from, as it drips every 2 seconds or so. It's dripping out of this hole on the bottom of the engine:

http://postimage.org/image/8vswxykpf/

It seems that it drips every couple seconds for about 10-15min after the engine is run, regardless of how long it was run for.

Any ideas what could cause this / what to look for???

The seal in the coolant pump is leaking. Its not a big job to fix it and you should be able to do it yourself.

The oil and coolant pumps work in on the same housing, there is a small air space between them and that vents to the hole you see the coolant comming from.

Crazy Frog aka Bert has some good bits in the downloads about fixing it.
If you haven't got a password for the downloads then PM Bert.

I am having the exact same problem as the coolant is leaking out of the very same hole at a seemingly similar pace.

Did you figure out how to fix this?

Ben

The coolant leaking out that hole means the seal on the pump is cactus Have a look at this and get the story https://www.k100-forum.com/t1070-replacing-the-water-oil-pump-seals

Thanks for the link. A good deal of the process seems to revolve around taking the pump apart, getting at the seal and replacing some obsolete parts so that they work with the new seal. Instead of doing all this I wonder if I'm just better off replacing the entire pump with the pump I have in my totaled k100rs. It would entail getting it out of the totaled one but that would be good practice for re-installing it.

One potential problem is that the totaled bike is totaled due to electrical damage so do you think theres a chance the new motor is fried?

Ben

Swapping pumps could be an easy option as long as they are compatible. What are the years of your rider, and donor bikes? Use a great sealant or risk leakage on reinstall... (ask me how I know)

To be quite honest the pump in the damaged bike is very likely to be on its last legs. I would just rebuild the pump that is on the bike and if it needs a new gear shaft then you may get a good one from the damaged bike or you may need to buy a new one.
A seal kit is not expensive and fairly easy to install just make absolutely sure the oil seal is the correct way round.
before you install the coolant seal.

Rick G wrote:To be quite honest the pump in the damaged bike is very likely to be on its last legs....
A seal kit is not expensive and fairly easy to install just make absolutely sure the oil seal is the correct way round.
before you install the coolant seal.

Be prepared to replace the shaft as well. I think that they corrode at the coolant/air seal interface. See pics in this post : https://www.k100-forum.com/t1968-85-k100rs-oil-waterpump-parts-confusion