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Coolant, Where's it going?

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I think I may have a coolant leak but I can't figure out where! Currently I have @ 15 hrs on the top end of an 01' CR 250 which was pressure tested at the time. I've topped off the radiator twice now since the top end, begining to think maybe there's a leak somewhere but havn't found any signs externally. Visually checked all hoses, connections, radiators, weep holes at front of motor and under water pump, even drained the tranny fluid but don't find any sign of a leak.:thumbsup:

I suppose it's possible it could be leaking into the combustion chamber? If so what affect would that have on the motor? It seems to be running fine.

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If it is leaking into the cylinder it wont run fine for long. I would consider taking the head off and looking at the top of the cylinder. Anything except the normal darkening of the cylinder head from combustion could be indication of coolant leaking in. You may have gotten luck enough that the amount is small enough to not cause damage. Make sure the dowel (little metal sleeve thing) is still there too. Could be as easy as a new gasket is needed.

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When you topped it off how low was it? If it's your head gasket then it'll be smoking strangely and the exhaust will smell funny. If you top it off completely and then ride it and the coolant pressurizes, it could be expanding and getting rid of the extra coolant while you're riding. (which is normal)

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I had an issue with my 01 125 radiator cap, it wore out and was letting coolant leak out of the overflow hose. So make sure your cap is holding the correct psi.. and the head gasket also sounds like it could be a possible.

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When you topped it off how low was it? If it's your head gasket then it'll be smoking strangely and the exhaust will smell funny. If you top it off completely and then ride it and the coolant pressurizes, it could be expanding and getting rid of the extra coolant while you're riding. (which is normal)

It's never been below the top of the fins and doesn't smoke or smell as far as I know. I should have read the manual before I posted, it does say that a coolant loss out the overflow of 20 to 60 cc's per outing is normal. I just checked, it took @ 30 cc's. I'll try to fasten some sort of catch bottle for the next ride, hopefully that's where it's going.

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Its normal for some coolant to get pushed out if you fill the radiator up completely. You need to leave some room for expansion.

60 oz is just under a half gallon. The bike doesn't even hold that much coolant.

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Could the radiator cap be worn out? This is rated at 1.1 I think, and maybe is lower now? Wouldn't a cylinder leak be more likely to let combustion pressure out rather than coolant in? If coolant leaks into trans, oil will look like a vanilla milkshake when drained.

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Its normal for some coolant to get pushed out if you fill the radiator up completely. You need to leave some room for expansion.

60 oz is just under a half gallon. The bike doesn't even hold that much coolant.

Yikes, should have been cc's not oz's. :thumbsup: I fixed that post. Thanks

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Yikes, should have been cc's not oz's. :thumbsup: I fixed that post. Thanks

I put a coolant overflow tank on my 500 and the coolant level in the tank definitely rises after the bike gets hot. Its come in handy a few times in technical stuff.

If the bike otherwise runs good I'd put my money on just normal overflow from expansion.

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Overflow expansion is most likely the culprit. I have seen and would try this. Just grab a water bottle, any will do and zip tie it to the radiator shroud. Run a hose to it and wait and see when you get done. Saves some money that way.

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Hi Hallsy, I agree with most of these guys that if you are topping it off before a ride you will definitely lose about what your losing which I agree is normal because of expansion.

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Ok if it's normal then my question is, are you guys still topping off before each ride or are you leaving it just above the fins and finding it will maintain this level with no further loss of fluid or problems with overheating?

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On my 500 I have an overflow tank, so its a moot point.

On my mom's 80 I just make sure its above the core.

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Ok I'll fasten a makeshift catch can for the next ride just to be sure. After that I'll run it a little lower and see if it will maintain. Thanks everyone!

Hey Yodiracer, If you didn't see the email the check is on the way, may be there allready?

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U guys ever heard of using black pepper as a leak stopper. I was at a race one time and sprang a leak in my radiator. A guy told me to use pepper to stop it. After about 15 of those little packs of pepper from the snack bar, my scoot was as good as new.

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There is a big problem with the theory of peeper or the old "egg in the radiator" deal. That is foreign matter that is not going to stay in place and will spread around the water jacket. I would not do it. But, to each his own.

Hallsy,

I would just go to the top of the fins. That is where I have always done it and never had a problem with over flow. That is on both my KDX and CR.

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