Morning all, Recently replaced the coolant in my 2017 Speed Triple 1050R. As mentioned on other threads, and as you may know, Triumph no longer sell the old (green) HOAT coolant, so it's been replaced with their new (pinky orange) D2053 OAT coolant, and because of that I gave the system a good flush out with deionized water first, ran up to temp, before draining again and refilling it with the new stuff. Everything seemed fine, and levels were good - initially after the first test ride (and after the bike was left to go stone cold), the expansion tank level went down to the MIN mark, so I topped it up a little to get it in between the MIN and MAX marks. I've taken the bike on a longer ride this morning, including in stop/start traffic where the fan was cutting in, and when looking at the expansion tank (while the bike is still hot), it is now above the MAX mark. The service manual says that when refilling the expansion tank after a coolant change to fill it to the MAX mark, so per the book I don't think I've overfilled it and not sure if what I am seeing now is expected/normal? (i.e. when hot). Or do I potentially have some other problem that might be causing this? NB: The service manual doesn't say if the bike should be cold or hot when checking the coolant level vs. the MIN / MAX marks on the expansion tank! TIA.
I wouldn't worry too much as long as the coolant remains above the min line. If it's overfilled it will spit out coolant at some point from the expansion tank via the vent pipe until it finds it's own level. I maintain mine just above the min line otherwise it tends too eject coolant and it rarely needs topping up between coolant changes.
Doesn't sound anything to worry about and more likely that you are trying to fill it too much trying to be on the safe side Sometimes only the "minimum mark" is good as the expansion volume needed needs all the tank capacity.
