coolant leakage

[john r b]

I was hoping someone could tell me why my coolant overflow is dripping? the bike has 8 hrs.logged. dripping while sitting idle, bike warm.not hot! I discovered this issue when changing the oil. warmed the bike up and noticed coolant every were . thanks for the help.

[desertgasser300]

Have you tried new cap?

[stainlesscycle]

if you overfill the radiators, it will leak until it gets right.. fluid should be to the top of the fins, not all the way full...

[Jakobi]

Both above replies are on the money. If you don't have the expansion tank and are over filling it it will push any excess coolant out as it warms up. The same applies is the cap isn't sealing or holding pressure. It could also be a head gasket thats allowing exhaust gasses to cross into the coolant passages which then over pressurizes the cooling system and makes it blow the cap valve open.

Try the easy fixes first and see where you end up. It could be as easy as some grit between the caps seal and the rad.

[john r b]

Thanks for the response guys. The cap has never been off. Until the discovery of leakage. The coolant level is still top of fins.????? thanks again.

[stainlesscycle]

does coolant look good or is there an oily film or any discoloration? if no, then it's not exhaust gas.

is it a 1.2 or 1.4 cap?

if it was mine i'd:

a: remove cap, start bike, watch coolant swirl a bit. this just checks waterpump operating properly - let it come up to temp a bit, it shouldn't boil until bike gets pretty hot...and fluid level should not change...

b: take a good look at cap and replace with known good cap - 1.4 works well.

c: triple check coolant level. coolant above the fins will leak out overflow..

d:check for leaks elsewhere - did you see it dripping out the overflow hose? could have come from somewhere else...

if the coolant level was high, it shouldn't be anymore - once it blows out the overflow a bit, it stabilizes...

[GMP]

Is this a '12? Check the sealing surface of the rad neck. Buff any rough coating smooth with a scotchbrite pad. Mine had this problem and lost all the coolant.

[steliost]

I have the same problem. I added a couple of rubber seals at the lower end of the cap to preload the spring. It seems to work so far. It blew up some fluid at first, I refilled it and it did OK for a three-hour ride, slippery singletrack mostly.
With the first chance I'll buy a 1.4 or higher rad cap for sure though. Does anybody know what brands fit except ktm?

[john r b]

Stainless, The bike is a 12' . No oil in the coolant . It looks great.
The cap is 1.8 once again this bike is new. I think this problem would have come to lite sooner?? Coolant is above fins not by much. Seems to be isolated to the overflow tube. First thing I did was check the head gasket.

Gmp. What did you discover? Cap related?

Should I try a different cap?

Smart carb. here i come.. I know unrelated...

[Jakobi]

John,

Glenns issue was some bad casting on the sealing surface of the rad itself which allowed water to sneak past the seal and blow out the overflow under pressure. If the water is just above the fins now, the cap is sealing correctly, and no contamination take it for a ride and bring it up to temp and then check for signs of further overflow. It may have been as simple as being over filled and purging as the fluid expanded.

Another SmartyCarb customer. Slided Bread! Here we come! Bring on the die cast models.