slight coolant loss from expansion tank, advice please?

[oldgreyandslow]

Got back from a reasonable ride this evening, put the bike back in the garage and when I went back after about 5 minutes I noticed a patch of liquid under the bike, it was definetly water and it appeared to have come from the expansion tank overflow pipe. at least I assume thats what it was and where it came from.

Took the side panel off and the seat unit to access the expansion tank and rad cap, there was water in the rad and the expansion tank was at min level.

Could it be there was just a bit to much coolant and as it got warm it overflowed? Or is it likely to be something more worrying?

I checked the hose connections and they all seem OK.

Any suggestions or better still reassurance welcome

Thanks

[Cammo]

As long as the bike isn't overheating, the radiators are full and you have some coolant in the expansion tank when cold (between min & max markings) everything should be fine. Might also pay to take the expansion tank off and test for leaks.

I wouldn't worry too much, it sounds like it's working as it's supposed to.

[porndoguk]

I would say there's a blockage, stat or pump fucked, reason being if its overheating and over flowing, then shrinking of the coolant when cold will suggest its the above.

remove the rad cap, blip the throttle and the level should go down, that will indicate the pump is functioning correctly, the stat will need removing to test,

Have a feel all the hoses and rads to see if there are any temp difference once warm,

Drain the system and fully inspect and measure the ammount of fluid drained, colour etc.

Rick

[oldgreyandslow]

I would say there's a blockage, stat or pump fucked, reason being if its overheating and over flowing, then shrinking of the coolant when cold will suggest its the above.

remove the rad cap, blip the throttle and the level should go down, that will indicate the pump is functioning correctly, the stat will need removing to test,

Have a feel all the hoses and rads to see if there are any temp difference once warm,

Drain the system and fully inspect and measure the ammount of fluid drained, colour etc.

Rick

I forgot to mention that it didn't overheat, never got above half way up the temperature gauge.

[Neosophist]

Easiest things first.

Have you checked the hoses taht run to the expansion tank? They often get cooked and go very brittle with age and the heat from the bike.. could just be a dripping hose.

[oldgreyandslow]

Easiest things first.

Have you checked the hoses taht run to the expansion tank? They often get cooked and go very brittle with age and the heat from the bike.. could just be a dripping hose.

I just ran it with side panels and seat cowl off with the bike supported on an abba and headstock stand so it was pretty much level so I could observe the expansion tank etc. Got it all real warm, the fan cut in and out twice and no leaks as far as I could see, the level in the expansion tank was at min when cold and max when hot.

I can only assume it was somehow overfilled before but it hadn't done this previously, or at least I didn't notice it.

Or the liquid was something else entirely

I'll go over all the hose connections just as a precaution anyway.