If you do find a crack, I have seen car radiators repaired by brazing. I don't know about using JBWeld, I can't bring myself to trust the stuff

Not having my bike here to go look at, I can't picture where you are seeing the leak or where it may be travelling from. A coolant system pressure test can help locate a leak.

 

here's a pic (guess not - won't let me upload the pics)

 

I have used JB weld to reinstall a radiator neck back in the 70s when I was broke and in the military, that stuff worked great. Have also sealed the fuel tank on the old Chevy trucks that leaked in the front corners, just rough up the area real good and make sure its dry.

If your leak is between the tank and the core you can use BG cooling system sealer and it wont plug anything up. Its good stuff also.

 

Okay, I think I found the leak. Just went to the store and came back, checked it and there was fluid on that same post. I looked between where the post connects to the radiator and the bushing and it is green (like my coolant) even after I wiped the coolant away. Looks like I'll be taking everything off again and let it dry out, then JB Weld it is (I don't have other welding equipment). Has to be a super small crack as I couldn't see it with my naked eye when I took it off before (explains why it isn't a steady drip).
Moral of this story is to remember that where the cement meets the asphalt may be steeper than what the shadows and dirt tell us. Doh! What a difference an extra 10mph makes.
Thanks for your replies

 

I had the same exact problem last year. The rubber bushing on the brake side post of the radiator didnt do its job and the constant vibrating caused it to crack the radiator. After googling I found out someone else had the same problem as well. I drained the radiator and brought it to a local radiator shop. They pressure tested it and there was a crack where the post connects to the radiator. They re-welded it for about 80 bucks. I hit it with some high temp black spray paint when it was done. Much cheaper than buying a new $400 radiator. Havent had a problem since. Heres a video of mine

 

I'll second JB weld. I used it on an older bike i had. Small crack in the crank case, filed it and ran JB weld in it. Held for years, and sold it to a friend...years later still no leak. Just let it dry as stated in the instructions.

 

I prefer quick steel over jb weld. I've used on oil pans, supercharger ports, and other parts on my race cars and bikes.

 

Took the radiator off and scraped away some paint - sure enough, crack where the post connects. The rubber bushing was broken to where it was missing a piece (not sure if that post is supposed to be indented only on the right side - guessing NOT - but mine is (in the shape of where it mounts. Sanded it down bare around the crack, JB Weld - will let it cure until Wed.
Put some RTV to fill the gap in the bushing. Saw one on-line for under 3 bucks, then about 20 bucks SH. If the RTV doesn't hold on the bushing I'll just fill it after I put it back on the bike.
I don't feel so bad knowing I'm not the only one who had this happen, thanks!

 

Mine did the same thing. I cleaned it good, and then welded it with aluminum rod. Worked great. ( Gas Weld )

 

Glad to see you've found your problem and maybe mine as well. After my wreck no puddle or drips that I saw but the wrecking company had it for 2 months. Got it all back together and went for a ride (after all of the short shakedown runs ) of 120 miles and at times could smell anti freeze but never saw anything. Overflow tank is showing low now. Could it be venting through a crack without ever showing a drip?

 

I used JB on a radiator for my drag car. Dropped radiator when I dropped new engine in and the radiator landed on the outlet neck and cracked it. I figured it would be a temp repair but it lasted as long as the car did.

 

I swear by that stuff, I bought a Honda that had a crack at the neck joint and it was plastic, but JB weld on it hoping to get a few miles out of it before I changed the radiator. I put a generous amount on it and it lasted years sold the car a few years later still wasn't leaking. Great Stuff!

 

And Harbor freight has some great aluminum rode that you can use with a standard map gas torch for home plumbing. Easy to use and work with and makes permanent repairs.
Part number is :Aluminum Welding Rods - Pack of 8 Low Temperature Rods

 

Mine was repaired using an epoxy at the same location a few months after purchasing after Kawasaki refused to warranty their junk. Its held up fine for 6 years.

 

Mine leaks same exact spot, I had it fixed at the rad shop and it lasted a month, I ordered a new rad, but it came in damaged so I sent it back, I've been adding water to the overflow for a while now, but not sure if it is being sucked up in the rad or not, I'll try to fix it, the hot light has never come on, but the fan does, as usual, once in a while.

 

Does anyone know if the overflow will suck the water into the rad, or do I need to take off the gas tank to add water?

 

If you're talking about adding coolant to the radiator first off be sure to read the recommendation in the manual (I think it calls for 60% water, 40% coolant - but could be wrong - either way it is close to 50/50 mixture). too much water can cause corrosion.
For adding it you don't actually have to remove the tank. I removed the bolt under the seat and popped it out at the top. I took a cut piece of 2x4 and wrapped it in a clean rag (to prevent scratching) and lifted the front left side of the tank and gently wedged it between the tank and frame to prop the tank up as high as it would go (a few inches). I took 1/2" diameter tubing (18" roughly) and a funnel (basically made a beer bong).
You have to go really slow when adding it, shining a flashlight in the hole. Put a tarp or something down because there is a chance you will overfill it and spill some (I did). remember that if you see the fluid coming up then anything already in the tubing and funnel is coming down and will overfill - so either go really slow or anticipate the spill and wash the bike immediately.

 

Make sure you replace the bushing with a new one otherwise you will be having the same problem again down the road.

 

thanks, guys, I replaced the rad since it was 10 years old, new bushings, too. When its hot it is up to the H level and cools down to the L level, so seems to be working properly, fan rarely goes on unless I let it idle or a really hot day and then only for a few seconds.

 

mine leaked by the right side post too, JB welded it and it holds fine since maybe 6 weeks

 

I know this doesn't pertain to your specific problem but it is coolant leak related. I talked to a few Kawasaki mechanics and they said whenever they get a bike in for service the metal clamps that secure the rubber hoses to the various coolant system parts are not necessarily loose but loose enough that they can be tightened by a couple of turns of the clamp screws. They felt the clamps are secured properly at the factory but time and cycles of hot/cold effect the hoses to where they are no longer as tight as they came from the factory. I know this is basic common sense stuff but, for those that may not know, the next time you've got your tank off and doing some maintenance to be sure to check all coolant hose clamps.

 

:smokin: Guilty as charged... :thud: Thanks for the reminder...

 

Mine was leaking in between the two cylinders come to find out it was the o-rings that are at the end of both coolant lines that go to each cylinder 8 cents for the o-rings $5 for shipping and $100 for the repair lol