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Coolant Leak?

10K views 16 replies 10 participants last post by  MakisRC51 
#1 ·
OK I'll start from the beginning. I ride an '06 and I noticed a spot of coolant on the garage floor a few weeks ago but assumed it came from the overflow hose. After my last ride I noticed some coolant collected on the bottom of the fairing. When I pulled off the fairing it looked like the coolant came from the left side radiator and dripped down. I can't see any evidence of a continuing leak on the radiator or hoses. They were bone dry when I looked at them. I did noticed a little discoloration on the bottom front corner of the radiator. Is it a semi normal occurrence for coolant to come out of a hose fitting or possibly the seam of the radiator? I'm riding from Ma to UT in may for the superbike race and I'd like to take care of this if its something serious before I leave. HELP!
 
#2 · (Edited)
Definatly not normal. Sure wouldn't take off on any trip with it like that.
Things to check,
1. the obvious, all hose and clamp connections should be clean and tight with no traces of leakage
2. Maybe your overflow bottle is somehow leaking
3. Check the condition of your radiator cap. If you cant pressure test it, replace it.
4. Check the inspection hose from water pump. It's on the right side. It should show zero sign of leaking. refer to picture...
Are there any other signs or things out of the ordinary when your bike is running? Like is it running slightly warmer? How's the volume of coolant?, it should be no more than 1/2 full in the overflow bottle with the rads full and engine cold.
 

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#5 ·
I had a similar problem coming from the right side. Only happened when warm, usually after shutting down, I looked closely yesterday and thank goodness it's coming from the radiator cap! I was almost weeping as bad as the radiator thinking about having to buy an new radiator, hopefully a new cap and I will be fine. Guess it's time after 11 years.
 
#6 ·
Similar Issue

I have a 2001 rc51 that i have had since 2003 with 500 miles on it. Now it has about 40k or so miles and I am having a similar issue. However the coolant leak that I am experiencing is coming from the "inspection tube." I removed the plastics and let it run on the stand. Once the temp hits about 180 i start to get a slow drip from that tube. Took it for a naked ride and same thing happens. When I came across this forum I noticed the checklist with the picture of the inspection tube an said EUREKA...

Any Idea what the leak form the inspection tube means?

Thank You!
 
#7 ·
It's time to refer to your Svc Manual. I don't have hands on experience with it, but that leaking from the inspection tube means your waterpump bearing are going out. I think. I only know what I've read about that, but it makes perfect sense to me.
 
#8 · (Edited)
The inspection tube is indicating your water pump mechanical seal is shot (the same is true for your car as well).
Coolant is leaking past the mechanical seal and into the cavity between the mechanical seal and the oil seal that divides the water pump shaft between the coolant side and oil side where the drive gear is.

Refer to the diagram below.
You need to replace the mechanical seal, oil seal, and water pump bearing (items 2, 8, and 10).

http://www.indyoem.com/fiche_sectio...ry=MOTORCYCLES&make=HONDA&year=2001&fveh=3620
 
#10 ·
Coolant is coolant as long as it's compatable with aluminum and safe for plastic your good to go.
Because of the big twins' thuds and vibration, both of the radiator's hose clamps, especially those close to the frame, should be checked for tightness every 3000 or so miles.
I check them every time I take off the fairings.
This was a item on the things to check for maintenance of the beast from a motorcycling mag reviewing buying/ownership issues for the SP-1 and 2. Mine was dripping from said clamps when I bought it, with 3700 miles on it.
 
#14 ·
Did you check if the smell comes from the exhaust?
I mean, if it smells that much the coolant somehow gets fried up....since you don't see any coolant around the engine or on the ground, it probably is in fumes mixed with the exhaust gases......just a thought

Sent from my X310e
 
#15 ·
well to be honest I not totally positive I fixed my leak. for a period of time after doing the hoses I was getting minor coolant stains on the left lower part of the frame. Then it magically fixed itself, and that was good enough for me because I'm sick of chasing the leak!
 
#17 ·
Ok it was just a thought :eek:

Next thing I would check would be the thermostat housing and underneath it, as well as all the cooling system's clamps.

Thorough removal of plastic, air box, throttle bodies and drain the system.
A nice chilled coffee, my favorite music and off I go.
Taking out each one clamp, use some kitchen green plastic scrub to clean the contacting surfaces (hose's and rad's ), thermostat's hoses as well and take apart the thermostat to check it's sealing condition around the rubber o-ring.
Don't forget to check the ECT sensor around it's thread for leaking.

Since it's not an urgent thing, you can take your time with it a Sunday morning for example. I would do that even if it would mean I would miss that week's ride......much more important to me the flawless bike's working that a ride smelling the antifreez deodorant all the way :D
 
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