Quick question regarding draining the oil after my water pump seal failed on my 2004 Gas Gas TXT Pro 125. I've replaced all the water pump components with a new kit (shaft seal, impeller, circlip etc) and wanted to ask about draining the sump. Obviously there was water ingress into the oil so my question is how do I go about ensuring I have gotten all the water out of the sump? 

Edited October 19, 20232 yr by MattAtreides

22 minutes ago, MattAtreides said:

Quick question regarding draining the oil after my water pump seal failed on my 2004 Gas Gas TXT Pro 125. I've replaced all the water pump components with a new kit (shaft seal, impeller, circlip etc) and wanted to ask about draining the sump. Obviously there was water ingress into the oil so my question is how do I go about ensuring I have gotten all the water out of the sump? 

To get milky oil out of the gearbox you drain the milky oil out the drain hole or by taking the clutch cover off and put dry oil in, go for a ride then drain that oil out then put dry oil in and go for another ride. Usually by then the oil is visually free of milkiness. If it is still a bit milky, drain it again and put in dry oil again.

It's not a big deal/damaging/dangerous to ride with milky gearbox oil. The action of the clutch might be a little different to normal. The oil is designed to keep the water away from the metal bits by encapsulating the water as billions of microscopic globules. The water globules are why the oil looks milky to the naked eye.

Evaporation 🤓 I dropped a whole motorcycle in the lake once and evaporation eventually worked.

Clutch plates absorb water and swell; pull the clutch friction plates and dry them in the sun, then check them for flatness and thickness to determine if they need replacement.  The rubberized cork friction plates are the only part in the transmission that can absorb water, everything else will just rust.

... plan on doing oil changes more frequently for a while.

Edited October 19, 20232 yr by lemur

I read that to test theamount of water in oil , heat some metal up and drop a drop of contaminated oil on it , if it fizzes lthen it needs changing , if it does not then it might only be the discolourisation you are noticing from the prevous seal failure. It should be ok on the 2,d or 3rd oil change, get the bike warm for a good 30 minutes to see if it evaporates and changes colour.