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Coolant leak

mtbmike

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Anyone here experienced a coolant leak. Well I got one 1800 miles looks like the radiator seam on the left side is leaking. Funny thing is when I first got the bike at around 40 miles I noticed a little white crusty coolant at the bottom of the water pump by the bottom most bolt. I cleaned it up and have not noticed anything come back but this morning after my ride into work it smelled like coolant I look down and there is dried up coolant all down the left side seam of the radiator dripping down the hose there's no drips but def leaking going to call the dealer today and get it handled. Bummer really nice days ahead after a brutal cold snap and snow for about a month. I guess this is why I have 2 bikes. There is no way the radiator leak could be related because the drip would have to travel down then up to the bottom of the water pump bolt. So I could potentially have problems with the water pump seal later on.



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Search "first complaint, unfortunately".
Edit: never mind the search engine is junk, search coolant leak and enter that thread
 
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Keep us posted on this issue. I had the dreaded coolant leak on an ST1300 twice with back to back water pump seal failures in 18 months :mad:
 
Funny thing is when I first got the bike at around 40 miles I noticed a little white crusty coolant at the bottom of the water pump by the bottom most bolt. I cleaned it up and have not noticed anything come back....So I could potentially have problems with the water pump seal later on.

This is the location of the bleed hole. A bit of seepage there initially or occasionally is not necessarily a sign of a problem. Probably it is all settled in now and everything is fine with the water pump. A constant drip from that location would mean that the mechanical seal is damaged. If so, the seal is not replaceable other than by replacing the pump assembly.

The leak on the left side seam is more troubling. If the seam was split, the radiator should not be able to hold pressure and there should be steam escaping. The only hose on the left side is the lower hose. You say there is dried up coolant "all down the left side". Possibly the lower hose is leaking under pressure and the wind from riding it has blown the coolant up (rather than down) the left side where it has dried. It is possible that all that is wrong with it is a slightly loose lower hose clamp. Be careful, as the clamp can be over-tightened damaging the lower pipe. If you have a set of calipers, the outside diameter of the hose clamp should be about 0.080" less than the outside diameter of the hose.

ETA: Common sense and probably unnecessary, but make sure that the hose is seated properly on the stub and that the clamp is in the right position before tightening it.
 
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Well got a good look at it during the day I noticed it going into work last night and it was pitch black so I could not see anything really well and when I went out later the condensation was covering everything up. There was a very strong coolant smell right after I parked. In the day it looks like its the lower radiator hose and when I ride it must kick up into the left side of the radiator giving the impression the left side is leaking thats my guess yes the hose and clamp are tight. Expansion tank appears to be at the correct level cold and hot once the bike cools I will pull the radiator cap off if its low its going to the dealer if its not then it must be some mag chloride or something wet on the street dried up one the hose I won't worry about it. Still can't explain the coolant smell though it was really strong and no apparent drip anywhere but then again it was dark and hard to see.

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I wasn't going to check the level in the radiator and just let the dealer look at it under warranty but the hell with it. Looks like the system is completely full so I guess I will keep riding. If I see something that warrants taking it in I will report but being in the business this is just going to be a no problem found I would imagine. I'm going to clean it up keep my eye on it and ride the dam thing!!!

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I had something like this happen to me a couple of months ago - I was riding home in a heavy down pour, got home and pulled into the garage, shut off the bike, got off and noticed quite a bit of steam coming off the front of the radiator along with a strong smell of coolant. I did not pay it much mind, as the whole bike was wet from all the rain, so I hung up my gear and went inside.

The next day I thought about it again and examined the dry radiator. I notice a bit of grey residue on the bottom right side of the radiator, so I gave the bike a good wash, oiled the chain and went for a ride. The bike ran fine, and when I got back I checked the coolant tank and it was at the full mark. The radiator cap was also on good and tight and I checked all the hose connections and they seemed fine and showed no signs of leaking or seepage.

This only happened once and the bike seems to be running fine.
 
Keep us posted on this issue. I had the dreaded coolant leak on an ST1300 twice with back to back water pump seal failures in 18 months :mad:
Did you diagnose the leaks as water pump failures or did a dealer? I pose the question because loose hose clamps masquerade as water pump leaks on the ST1300 but the dealer makes a whole lot more replacing a WP compared to tightening the hose clamps on the thermostat housing.
 
I have owned three new motorcycles, the NC (which I don't have yet) will be my fourth new machine. All three new motorcycles had slight coolant leaks during the first season. In all three cases the problem was at the hose clamps. Two of them were solved by tightening hose clamps. The Suzuki had a slightly more serious problem; the radiator was painted with paint that came loose under the hose clamps, and coolant seeped out under the paint chips, which meant I had to drain the cooling system and take those connections apart to solve the problem, but even there I didn't have to buy any parts or disassemble any farther.

If I smell coolant on my NC, I'll go looking for a loose hose clamp and I bet I'll find one.
 
Anyone here experienced a coolant leak. Well I got one 1800 miles looks like the radiator seam on the left side is leaking. Funny thing is when I first got the bike at around 40 miles I noticed a little white crusty coolant at the bottom of the water pump by the bottom most bolt. I cleaned it up and have not noticed anything come back but this morning after my ride into work it smelled like coolant I look down and there is dried up coolant all down the left side seam of the radiator dripping down the hose there's no drips but def leaking going to call the dealer today and get it handled. Bummer really nice days ahead after a brutal cold snap and snow for about a month. I guess this is why I have 2 bikes. There is no way the radiator leak could be related because the drip would have to travel down then up to the bottom of the water pump bolt. So I could potentially have problems with the water pump seal later on.

Sent from my Nokia Lumia 1020

4.jpgIf you NC7 is under warranty, take the bike to the dealership! Honda keeps records on warranty claims, and if it is a problem they want to know about it.

smileySkelton.jpg

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I would surely keep an eye on coolant level.

One of the very few things that concern me on the NC is the "open deck" cylinder design that may mean less toleration to high thermal loads/overheating.
This sprung to mind as the EJ25 Subaru 2.5 litre normally aspirated engine with similar design (albeit most probably thinner cylinder walls for almost double capacity and oversquare cylinder) is prone to gasket failure.
Maybe the new 750 engine could be more of such concern, maybe not.

Mind you, I am nitpicking now!
 
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Did you diagnose the leaks as water pump failures or did a dealer? I pose the question because loose hose clamps masquerade as water pump leaks on the ST1300 but the dealer makes a whole lot more replacing a WP compared to tightening the hose clamps on the thermostat housing.

It was not loose clamps. My hours of research on the ST-Owners forum and consulting with my mechanic lead to my unfortunate discoveries. When the engine was fired up, the only place it would leak from was the round weep hole -- not the drainage holes. I know the STs are notorious for leaky clamps. I wasn't that lucky.
 
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When I got my NC at first I was plagued by an apparent "coolant leak" from the left side of the radiator. I went through the various precautions one does to trace such a leak. However I could never catch it in the act so to speak. It was doing my head in but the coolant level never dropped. Each time I stopped the bike I would see the spatters of "coolant" on the left side on the frame and the head near the water pump. There are now 15000kms on the bike and I never found the leak. Reason is that there never was a leak.

The culprit was the radiator itself in this instance. When you wash this bike, even if you let it rest on the sidestand, water never completely drains from the radiator struts/vanes. It just sits there among the cooling struts on the left side. Because the radiator is only painted on its outer surface, the inner parts of the struts are bare alloy. This means that the trapped water absorbs some dissolved aspects of the alloy.

As soon as the bike moves up to speed, the solution trapped in the radiator gets blown back and leaves its stains where I was finding them. There was no leak. I only found out this by accident as it was clear that sometimes for up to a week at a time there was no sign of coolant leak. I then put two and two together and realised that it only happened after I washed the bike. It still happens occasionally but only after washing the bike or if it is left out in a rain storm. This may be your problem also.

Assuming you have checked all the hose clips, another culprit can be the water pump shaft seal. However I would only expect that to happen in a bike with very high mileage like my FJS 600 which did this at 55000 miles. Even then it was only doing it in wintertime and mostly at weekends. Reason being that the bike would cool down at night and the temperature would often drop below freezing. Next day if the bike was not being used and there was a significant increase in temperature, the coolant would expand and a little would slip past the worn seal, and on to the ground. It would not happen on weekdays as the bike was being used and the seal would tighten sufficiently on the shaft with the sudden increase to operating temperature. It only ever lost a few cc's over the winter. It was never bad enough for me to do anything about it. The bike is still running and the current owner is aware of the issue which to him still is not an issue.

The other culprit could be the water pump gasket. Again that is unlikely. Hopefully the first description is your culprit. I hope all this makes sense.
 
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I'm in the habit after washing it is to ride it a few times around the block or at least to start the engine and let it idle long enough for the radiator fans to cycle once before I roll it in the garage and leave it. I started doing this with the ST1300 because trapped moisture under the plastic fairing can start corrosion in/on inaccessible areas and heat from the engine helps quickly evaporate water. I do the same with the NC.
 
It was not loose clamps. My hours of research on the ST-Owners forum and consulting with my mechanic lead to my unfortunate discoveries. When the engine was fired up, the only place it would leak from was the round weep hole -- not the drainage holes. I know the STs are notorious for leaky clamps. I wasn't that lucky.
I'll say two water pump leaks back to back is extremely unlucky. I thought I had a water pump leak at IIRC 65,000 miles as the area around the round weep hole and right side of the engine was grimy and stained but cleaning and snugging the clamps then careful monitoring over the next 20,000 miles revealed it was coolant from above hoses coming out of the square drain hole and blowing down and back over the round weep hole. At 130,000 I'm still leak free.
 
I'll say two water pump leaks back to back is extremely unlucky. I thought I had a water pump leak at IIRC 65,000 miles as the area around the round weep hole and right side of the engine was grimy and stained but cleaning and snugging the clamps then careful monitoring over the next 20,000 miles revealed it was coolant from above hoses coming out of the square drain hole and blowing down and back over the round weep hole. At 130,000 I'm still leak free.

The situation with the ST aggravated me enough to sell it (which I did the following day with full disclosure to the buyer). I'm happy with my NC. But focusing on this thread, sounds like the NC also uses a similar impeller with a ceramic face that mates up to a rubber seal so I suspect some weep hole leakage at times may occur. Anyhow, I hope my luck changes!
 
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