Squirting coolant when hot

[pookie]

I thought my sv1000 was drinking coolant until recently noticed it peeing it out when I parked up. It seems when riding through town and getting hot it squirts it out of the drainage hose on the right side of the bike. It was rather hot and the fan had kicked it. its the second time its happened in 6 months and both times when having a prolonged slow ride through london.

I`ve been really paranoid so have been checking the fluid level regularly over the last 6 months and gently topping up. The last time I checked was 2 weeks ago about 150 miles and it was in between low - high. Normally I fill her up higher so i can see it from the reserve tank.

Any ideas why this is happening and is a symptom of some thing else? cheers

[ophic]

Originally Posted by pookie

Normally I fill her up higher so i can see it from the reserve tank.

Perhaps this could be why its peeing out?

Dunno why the level would drop so suddenly though - not without other symptoms. Is your oil milky?

It will do that. An expansion bottle connected up to the radiator system which is under pressure. If this bottle overflows then some of this is released via the overflow pipe, onto the floor.

It can overflow for a number of reasons, one of these being the system was overfilled in the first place.

I am sure someone more knowledgeable will tell you the others in short order though.

Dan

Both my thous do it. Seems worse when parked on an incline. At first I thought the 03 had a failed headgasket from when the radiator holed and I limped it home. The actual amounts required to bring it up to the full mark are very small but it's damned annoying having to lift the tank to do it.

How hot are we talking?

[jambo]

"Plenty more where that came from"

Not helpful? I'll try a little harder then. Sudoxe (edit: and Ophic) have got it, if you over fill the expansion bottle when cold, then when hot, and the excess pressure from the coolant system is being released by letting coolant pass into the expansion bottle then it gets too full. This is where the over flow pipe comes in handy, neatly depositing the excess (in the case of my ZX6R, over the rear tyre).

The pertinent question is, once the bike's cooled completely, and is level, how much is in the expansion bottle then? If it's between upper and lower it's fine, continuing to add more will simply deposit that much or a bit more on the ground next time the system gets hot.

This pre-supposes that the fan is kicking in in a sensible range (~104-109C) and is able to bring the temperature of the system back down while running and then switches itself off.

Jambo

Providing it is not dropping below the minimum level it is just finding its own level.
The fan cuts in on my bike when in traffic and it seems that my water level is just below the minimum mark. Every time I fill/top it up it just blows it out till it has gone back down to this level but if I leave it it doesn't drop any lower

The volume of coolant will expand as it gets hotter (the reason you have an expansion bottle). If the volume in the expansion tank is too high it will force coolant out of the breather (it basicaly finds it own level).
It's nothing to worry about, just keep an eye on the level.
Don't forget as the weather gets hotter so will the bike. The coolant temp will rise quicker from 25c to 100c than it will from 2c to a 100c. For this reason it's probably worth checking the coolant level when the bike is up to temp.
Don't forget it's a pressurised system though so be carefall if removing lids.

[yorkie_chris]

No sense in pulling the rad cap off when hot.

Do this cold. If the rad is full and there is something in the expansion tank when cold it will be fine.

Agree with yc totaly, reading back that was put a bit confusingly.