King Cat won't stop weaping???

[TKrug21]

King Cat carb, rebuilt the top end of the motor, left the original water pump in place. Got the motor put back together, filled with coolant, no problem. After the first run couple of minutes, coolant leaking. Tracked it to the weap hole behind the pump. Pulled the seal out, replaced it with a new one. I even put a little silicone around the lip of the metal part, and inside the impeller where it mounts to the shaft, just to be sure.
Filled with coolant, no problem. Start and run, start leaking again. WTF?????
Now here is the interesting part, engine running, cap off(no pressure), the leak stops. Put the cap on or shut the engine off, starts dripping.
This is a steady drip about 2 seconds apart, and will drain the whole engine part of the system in a few hours.
I just don't understand how that much coolant can be getting past a brand new seal.
And yes, I checked with the mechanic at the dealer to make sure I put the part in the back of the impeller in correctly.
I am at a loss, is there something I'm missing, something I can do differently, just don't understand.
Any ideas?

 

[greasemonkey3406]

Im kind of wondering the same thing. I replaced the seal on my 1010 because it would leak if left sitting. It was ok for a while but now if u start it up in the garage and run it for a bit, it will leak a little bit out on the floor and then stop.
The only thing I can think of is that I did not change the seal under the bolt that holds the impeller on because the dealer didn't have one in stock.

 

[tundramonkey]

It could be leaking at the point where the water pump housing meets the case halves. I had this exact issue after putting my motor together. You will need to pull the motor and pressure test it before pulling anything off the motor. Use soapy water in a spray bottle to find the leak.

 

[mountaincat 800]

Try it again. This time with no silicone and try not to get any grease or oil on the mechanical seal.

 

[greasemonkey3406]

Anyone know the purpose of that little rubber washer that goes between the bolt and the impeller?

 

[MT Backcountry]

Seal

I think it protects from leakage through from the bolt side.

 

[greasemonkey3406]

That's what I was thinking too but it still looks like it would have to get past the mechanical seal to be able to leak out through the weep hole. I just replaced that seal but the dealer didn't have a rubber washer in stock so I put the old one back in. It will only leak for a little bit and then stop. I have the sled for sale but I don't want to sell it with a leak so I might have to haul the engine back out again and replace that washer.