I have that much of the problem stems from a deposit of some foreign material on the shaft, making it hard for the seal to work. Removing the shaft and scraping it clean with a fingernail, or 600 grit paper has cured most leaking water pump seals that I have found. If one were to replace the single water side seal without cleaning off the shaft, the leak will more than likely return shortly..

 

S.

 The material is from the plastic impellor itself. Nothing foreign about it. It is it`s own shavings.

I have a 2018 RR 300. I'm on my third water pump shaft, improper,  and fifth set of seals. I've done it myself a couple of times, and had it done professionally a couple of times thinking I did something wrong... always the same result.  Everything will run great for about 2 months. Then the tell tale sign leaking out of the weep holes between the seals. Frustrating. 

These days I just top up the coolant fluid if I know I'm only going out for a couple of hours.  

A fellow Beta bike owner mentioned he had a similar issue until he bought the Jitsie after market set up. Will this fit our TRS's? Anything else? 

Dont fill the radiator to the top, leave 10mm air gap to allow for water expansion. Radiator too full will cause excess pressure and push water past the seal.

Had to replace my seals at 130 hrs.  Nothing to do with coolant level.

The shaft was noticeably grooved but I put it back together and so far is ok at 200 hrs.  If it does it again I'll do the shaft as well.

On 11/30/2019 at 4:10 PM, Spanky said:

Dont fill the radiator to the top, leave 10mm air gap to allow for water expansion. Radiator too full will cause excess pressure and push water past the seal.

That shouldn't happen. The radiator has a pressure relief valve built into it. 

The pressure relief valves don't always work,not as good as a proper radiator cap,but presumably cheaper.

3 hours ago, huski said:

The pressure relief valves don't always work,not as good as a proper radiator cap,but presumably cheaper.

 I don't imagine that a radiatior with two threaded holes and a seperat filler cap and pressure relief valve would be cheaper. I'd guess it's done to keep things compact.

Certainly more compact,harder to fill and check coolant level?Harder and more time consuming to make an old style filler neck and attach it to the rad than the present method.The filler plug is only a bolt,and the relief valves are under £5.2 alloy bosses drilled and tapped,tig welded to rad,job done 

If pump shaft is grooved, i.e worn, then it will need changing as well as new seals. Any Gas Gas owner with water pump problems will testify.