Coolant Leak

Hi,

After each time I fill up with coolant it is despersed over the following 24 hours. It is dripping from the bottom of the breather that runs around the R/H side engine casing (to the left of the oil filler cap).

I have had a quick look to see where this breather is connected to, but I only got as far following it behind the frame.

Can anyone tell me what this should be connected to?

Thanks

The breather pipe goes from near the floor by the R/H engine casing up to the back of the petrol tank where the petrol tank overflow joins with a T-piece. It then continues along the left side of the bike following the path of the frame around the front and back a little bit where it connects to the very top of the coolant overflow/expansion reservoir - just beneath the rubber stopper. There should be a hose from the bottom of the reservoir to the very top of the actual radiator just below the cap.

This isn't incredibly clear but might give you a better idea:
http://www.robinsonsfoundry.co.uk/co...diatorhose.htm

If it is coolant coming out of the pipe then it seems like it is joined up to some part of the coolant system!

When you fill it are you filling it full to the brim or within the Min/Max lines maked on the reservoir bottle? It can be really hard to see the level because the "clear" plastic gets very cloudy on older bikes. If you brim it then all that's happening is that the radiator is heating up and the water inside expands forcing the fluid in the reservoir to exit by your right foot. You can see the Max/Min lines a bit easier if you use a torch and/or get someone else to rock the bike a bit whilst filling.

Thanks for that.

I still cannot see through the min/max clear plastic even with a light and the aforementioned 'rocking'.

I have filled up to the brim by mistake, but then taken some out. It is completely emptying all of the coolant though. Any time I fill up there is a rather large puddle under my bike the next day. Also the bike gets very hot at the end of my hour long commute if I'm being a bit 'enthusiatic'...which most of the time, encourages the fans to kick in.

I have to book the bike in for a service soon so I guess I will just mention it then. I was hoping it was something I could do my self.

[muzikill]

Well since its emptying it'll do you no harm to flush it out, take the flush bolt out at the pump just above the oil cap, stuff a container below it and run some coolant through. I'd be checking the overflow bottle for crud at the bottom just to be safe. Its maybe worth taking off the radiator hoses when its empty and give them an inspection around when they clip in. Run some water through the radiator with the left hand one off and a container underneath top see if it flows fully to check there are no blockages in the radiator.

Its not that hard to check the cooling 'circuit' if you take you time to read it over and follow it round the engine.

[muzikill]

Originally Posted by Chalky

Thanks for that.

I still cannot see through the min/max clear plastic even with a light and the aforementioned 'rocking'.

I have filled up to the brim by mistake, but then taken some out. It is completely emptying all of the coolant though. Any time I fill up there is a rather large puddle under my bike the next day. Also the bike gets very hot at the end of my hour long commute if I'm being a bit 'enthusiatic'...which most of the time, encourages the fans to kick in.

I have to book the bike in for a service soon so I guess I will just mention it then. I was hoping it was something I could do my self.

Get it checked ..... 'service soon' may be something you regret about leaving until it's too late! ...... think about what your engine may do if you let it get too hot ...... false economy.....unless you have loadsa money!

[dizzyblonde]

If its leaking from the breather, is it just that its ovr full, and finding its own natural level.

VRaptor did this for a while after it ran, had a wee the size of a teaspoon(looked a lot at the time), when she was switched off. Shes stopped it now, as shes at the correct level.

Tiz what breathers are for apparently

[muzikill]

or it could be a simple as dizzy says! ........... thats bikes for ya!

[jambo]

There is a distinction here that is quite important: "completely empty"

The vast majority of your coolant is in the engine block, and radiator. When you say "empty", when the engine's cool be very sure that you check the radiator, if this is full then the engine is getting coolant and you're fairly safe from immediate harm.

When a fluid is heated it expands, and thus takes up more room. The coolant system pressurises up to a point, then the radiator cap allows some fluid past the seal to stop the pressure rising too much. This goes into the coolant expansion bottle (where the min/max lines are). If there is already a lot of coolant in there then this bottle fills up and the excess runs out of the breather hose onto the floor.

When the system cools the fluid contracts and the pressure drops, coolant is then pulled back into the main system from the expansion tank via a 2nd valve in the radiator cap.

So we have a few options here:
1) The coolant expansion tank is over-filled as the min/max lines are hard to see and the excess ending up on the floor.
2) The radiator cap is faulty and instead of the system pressurising, too much of the coolant is ending up in the expansion tank, so exiting the breather hose and then onto the floor (different from option 1 in that the entire expansion bottle wil probaby be empty when cool).
3) Your system is genuinely emptying of water including the radiator in which case it is not smart to drive the vehicle until this is fixed.

If you look at the radiator cap, there is a small hose going back to the bottom of the expansion bottle. Pull this off and empty the coolant into a container. I think you might be surprised how much is still in the expansion tank even if you can't see it easily

Hope this helps.
Jambo