Coolant Leak

[RedNigel]

I think its probably coincidence BUT
I just walked into the garage after the polar snap that just finished and found a small puddle of coolant under my NT. I am going to have to remove at leat the left side tupperware to suss out the origin of the leak but i am bummed. I am assuming the leak is on the left side of the engine, as there is a trail of coolant running down the side of the left crankcase cover on the H in Honda. See pic below. It seems counterintuitive that something froze and burst during the cold snap since its coolant...any thoughts?

 

[ARKNT]

Since you have coolant in there it is not likely to freeze & bust. When these hard cold fronts come in though the different materials contract & expand at different rates and could lead to minor temporary leaks but yours looks more than that.
Best to remove some plastic and see what is going on.
These temperature extremes are hard on stuff, including me.

Arknt

 

[ST1100Y]

Inspection of coolant lines and clips is an annual (at least bi-annual) thing... constant tension hose-clamps might help though...
My GF's '07 NT700VA is due for another big service this spring anyway... undress, remove tank and radiator, etc...

 

[mikesim]

Before I would get too carried away with disassembly, I would check the coolant level in the overflow tank and if it is good, clean up the witness marks from the previous leaks and take it for a short ride and then park it and see if the leak returns. One of the hardest things on machinery is lack of use and sometimes seals can distort and cause a tiny leak that goes away with use. I have noted this a time or two on Traveller when it is parked for an extended period.

Mike

 

[junglejim]

The water pumps are known to weep in the conditions you describe. But I’ve never seen one weep that much. As noted above check the hose connections first.

 

[RedNigel]

Before I would get too carried away with disassembly, I would check the coolant level in the overflow tank and if it is good, clean up the witness marks from the previous leaks and take it for a short ride and then park it and see if the leak returns. One of the hardest things on machinery is lack of use and sometimes seals can distort and cause a tiny leak that goes away with use. I have noted this a time or two on Traveller when it is parked for an extended period.

Mike

MIke now that you mention it, I have had a ride or two where coolant leaked out but did not persist. I'm going to try a little ride first. I have to say that the puddle under my bike is not growing, so it did leak a finite amount, that i wouldn't call more than a tablespoon... if that.

 

[cliffh]

MIke now that you mention it, I have had a ride or two where coolant leaked out but did not persist. I'm going to try a little ride first. I have to say that the puddle under my bike is not growing, so it did leak a finite amount, that i wouldn't call more than a tablespoon... if that.

My Goldwing has done that several times during it's 31 year life, and every time, it quit after a short ride. My NT700 also shares this trait. It has never seeped enough to notice a level change in the coolant tank.

Cliff

 

[mikesim]

MIke now that you mention it, I have had a ride or two where coolant leaked out but did not persist. I'm going to try a little ride first. I have to say that the puddle under my bike is not growing, so it did leak a finite amount, that i wouldn't call more than a tablespoon... if that.

Yup, the most I've seen from my NT is about three to four drops. After the ride, the leak is gone and the coolant level in the overflow reservoir appears unchanged.

Mike

 

[JQL]

The NT does weep a little in colder temperatures. But...

Check the hoses especially the ones next to the thermostat (yes I know it's on the other side of the bike - DAMHIK), as there's a little rubber O ring which is supposed to be in the short hose that connects to the thermostat and quite often it's not replaced if the thermostat, radiator or fan have needed servicing.

Also, according to the manual, the hose clamps are supposed to be tightened so that they sink 1 mm into the hoses.

Yes, I've just changed the thermostat and the short hose on my NT yesterday! That's how I know

 

[moriniman2011]

Also had the 'little puddle that goes away' syndrome over the winter - sitting on the side stand - for a few weeks without being ridden. No obvious leaks and water pump area was taken apart and resealed/replumbed last year. One other point to check though is the little connecting pipe between the cylinders - this can weep and when hot the leak evaporates but when cold can run down if the bike is on the side stand. If on the centre stand then can remain undetected. Fiddly to replace seals and very short length of hose.....

 

[JQL]

OK. I was just putting my plastic back on after changing the thermostat and the hose next to it and I thought "I had better check all the other hoses"...

There is a tiny weap from the pipe connecting the two cylinders together . If the leak was bigger it would produce the "coolant stain" you can see on your crankcase. I note from the fiche that there are 2 O-Rings inside the hose and that the pipe looks like it is metal or metallic.

Has anyone worked on this hose before? And, if so, is it metal and how does it come out?

 

[moriniman2011]

Changed mine a few years ago - having plumbing experience helped..... Can be reached relatively easily after plastic and tank removal if memory serves well. Think it was rubber but looking back I only ordered the 2 clips (90601MEG000) and 2 O rings (91310KE8003) so maybe it was metal with O rings rather than a simple jubilee clip. Done nearly 8 years ago and (touch wood!) seems fine today 25k miles on - yes I need to ride more! Not sure why a simple bit of rubber hose (concertina type like an old Mini by-pass hose??) and 2 jubilee clips wouldn't work though (heat??) if parts were a problem.

 

[silshooter]

At around 20k miles I had to replace the radiator. It was ruptured at the metal attachment point to the frame.

 

[DirtFlier]

I too have noticed minor drips on the floor with a motorcycle inactivity over the winter and like others, I find it goes away completely once spring riding arrives.

 

[JQL]

I too have noticed minor drips on the floor with a motorcycle inactivity over the winter and like others, I find it goes away completely once spring riding arrives.

That's how mine started 3 years ago... Now it's much more serious in the cold weather with quite a pool forming over a couple of days or so. If you get chance, replace the O-rings asap.

 

[JQL]

I have just replaced the 2 'O'-Rings on the coolant pipe between the cylinders on my NT700VAA. It is relatively easy once you know the trick to getting the 'O'-rings off and on (discussed in the video below).

My YouTube video discussing how to change the 'O'-Rings:

Note, the video assumes you know how to remove the fairing...

 

[RedNigel]

I finally got the time to pull the bike out yesterday and found a newer, bigger puddle under the bike. I took it out and rode long enought to get some temperature into it and it hasnt leaked but its on the centerstand...SHould I put it on the side stand? I did some minimal investigating and it doesnt seem like the leak is emanating from between the jugs

 

[JQL]

With the bike on the side stand, put a paper towel between the cylinders and let the bike cool down for about 12 - 24 hours. After which check the towel. If it's wet, change the O-rings. If it's not, the leak is elsewhere.

 

[mikesim]

I finally got the time to pull the bike out yesterday and found a newer, bigger puddle under the bike. I took it out and rode long enought to get some temperature into it and it hasnt leaked but its on the centerstand...SHould I put it on the side stand? I did some minimal investigating and it doesnt seem like the leak is emanating from between the jugs

With the bike on the center stand, the coolant could possibly "puddle" somewhere and not be visible. I would put it on the side stand and let it sit overnight.

Mike

 

[ARKNT]

With a repeating leak it will need repair soon. I like the idea of paper towels in a few spots to absorb the leak as it sits to help locate it.

Arknt