Yet Another Coolant Leak Thread

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I think I have the dreaded leaky clamp problem. I pulled the tupperware yesterday to deal with my fork seals (and new Gold Valves) and noticed a couple of drops of a-freeze on the inside of the lower cowls. Coolant is dripping down the front of the engine along the right side of the clutch cover and also out the small square hole on the right front side of the engine. (See photos). Radiator and attached hoses are dry as a bone w/ no signs of leakage.

I assume I have the same problem nikonhonda wrote about - the other end of the fat hoses coming off the radiator are leaking in the 'V' between cylinder banks.

I initially planned to let this slide until the winter layup - there have been no leaks on the garage floor, I ride a couple of hundred miles a week with a MC club, and there is plenty of juice in the radiator overflow bottle. The leak seems very minor. Q 1. Should I wait or since the forks are coming off, this provides unfettered access to the radiator and just bite the bullet and do it now?

Q 2. Am I correct in my diagnosis that pulling the radiator is necessary and then I follow the hoses to the end and change/tighten the clamps?
Mark wrote about Gates powerclamps solving the problem. McMaster Carr is a 20 minute drive away, so I would just pick up a pair of these clamps and swap them out.
side of engine.jpg Front of engine.jpg
Sorry about the pics loading sideways. Left pic is of the square hole on the right side of the engine; right pic is of the front clutch cover. Right edge of both pics should be on the bottom. Bike is a 2010 1300 36,000 miles young.
 
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IMO I would leave it for a bad weather day or the winter, as our riding time where i live is too short so we need to take advantage of this time.
 
OP
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IMO I would leave it for a bad weather day or the winter, as our riding time where i live is too short so we need to take advantage of this time.
That is exactly my feeling - every winter I strip the tupperware off the bike, clean and wax it and do routine brake, engine, etc. maintenance anyway. Riding time here in NE Ohio is short enough.
 

BakerBoy

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My opinion: no hurry--just check the overflow bottle to make sure it's not low. The intermittent leak can be left unaddressed for months or years if one so desires (so long as you confirm it is only leaking on startup before everything is up to normal operating temperature). Mine dripped for a few minutes immediately on startup, but the coolant wouldn't show up drippig out of the engine for a few minutes--it always was dry after a ride.

When you do go after the problem, best approach is removing the radiator (and tilting the tank and removing the entire airbox assembly). Be careful of positioning and ortientation of the clamps--for example make sure you can still straight-on access the right cylinder bank cam chain tensioner.
 
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Inspect the connection for evidence of long term corrosion caused by a slow drip. By slow, I'm talking about one the doesn't run down the hose or drip much...that basically just keeps the area outside the clamp area damp. If you have this condition, may want to pull the hose off before simply tightening the clamp. When I refurbished my 1991, I found several connections that had deep pits in the aluminum just under the clamping area. One cleaned up well with steel wool so I left it and installed the new hose. The others were at the thermostat housing. Pits were so deep that I replaced the housing. I was concerned that the dripping would continue with the new hose and clamps installed. The only evidence was the blue and green aluminum oxide showing around the perimeter of the hose end.
 
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Looks like you have the plastic off already. It is only half of an hour more work to drain and drop the radiator, and another half of an hour to rehang the radiator and fill with new coolant. Replace or tighten the big hose clamp part is easy. I would do it now and ease my mind. I have been dealing with coolant leak from the last few years. Riding with a loose clamp knowingly just doesn't sit right with me.
Kenny
 
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Looks like you have the plastic off already. It is only half of an hour more work to drain and drop the radiator, and another half of an hour to rehang the radiator and fill with new coolant. Replace or tighten the big hose clamp part is easy. I would do it now and ease my mind. I have been dealing with coolant leak from the last few years. Riding with a loose clamp knowingly just doesn't sit right with me.
Kenny
I'll see how the Gold Valve installation goes. Once the forks are off, I will have mega access, and will decide at that point. Swapped my rear tire today - mounting the new Angel GT was a job not exactly made in heaven. Might have to boil the new front tire for 40 days and 40 nights to soften it up for mounting. We will see.
 
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Last edited:
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Ahh the dreaded cold startup coolant leak, I have been battling this since I bought my 09 new. I have since replaced the clamps on the cylinder water outlet elbows with wider clamps and thought that was the end of it. Not so much as my leak has now reared its' ugly head. I was thinking about using stepless Oetiker clamps on these hoses, even though they are not serviceable roadside, they seem that they would be better able to deal with thermal expansion/contraction. What do you guys think?
Size-11-16-17-mm-Oetiker-Stepless-Ear-Clamps-Single-Ear-Hose-Clamps-50-Pack--6.jpg
 

st11ray

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Gates Power Grip Shrinkband clamps. I think SuprSabre' son has used them. They are designed specifically for cold water leaks.
 
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For all connections for the coolant hoses, prior to the connection and whatever clamp is used, a thin application of copper kote or equivalent is the ticket as it seals, and when it is time for the hose to be removed, easy...
 
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Gates Power Grip Shrinkband clamps. I think SuprSabre' son has used them. They are designed specifically for cold water leaks.
Interesting... had never heard of these before. Googled it and am surprised that they have been around for years. From the tests, they seem superior to anything else so im left wondering... if they are that good, why arent they mainstream? Never did look up the cost.
 
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My bike was leaking the first winter I owned it (I got it used @9000 miles and 5 years old) I pulled the radiator so I could flush it and while the radiator was out I addressed leaks. The stock hose clamps are fine, they just need a bit of tightening. Many have over tightened and jacked up perfectly good hoses then blaming it on the clamps as being crap. I now have 70,000 miles on my 2007 and have not had a leak in the past 5 years since tweaking the hose clamps. Tighten clamps until you begin to feel a slight rise in torque--stop--your good. Good luck
 

flip-flop

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Looks like mine, but mine is less extreme. Another job to do!
I am very interested in those shrink clamps— are all clamp locations accessible to a heat gun?

Might as well do a starter valve sync while I’m in there.....
 

SupraSabre

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Looks like mine, but mine is less extreme. Another job to do!
I am very interested in those shrink clamps— are all clamp locations accessible to a heat gun?

Might as well do a starter valve sync while I’m in there.....
After Justin tried them, I did too. But in the picture below, the shrink hose clamps did not work for the smaller connects, they couldn't shrink up enough and they leaked.

thermostat-thermoplastic-clamps_new.jpg

So, instead we used the small fuel clamps from NAPA for those connections.
 
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I have a 2009 Honda ST1300pa coolant leaking from square hole when cold start... what is that mean?
 
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