Cooling system service

[mikesim]

It's time for Traveller's first cooling system service. In reading the manual, Honda recommend replacing the tow sealing washers on the drain bolts at the cylinder and water pump. I believe the water pump bolt sealing washer is a Honda p/n 90463-ML7-000, but I'll be darned if I can find the parts diagram that shows the sealing washer for the cylinder. Does anyone have these p/n's?

Mike

 

[dnktng]

Mike, I don't think that the "crankcase drain bolt" between the cylinders exist. If it does exist, I didn't remove it to replace the coolant in the NT. The drain bolt at the pump seems to drain all the coolant.

My service manual is marked up so I don't go looking for the "crankcase drain bolt" the next coolant change.

 

[Chucksklrst]

Mike, I don't think that the "crankcase drain bolt" between the cylinders exist. If it does exist, I didn't remove it to replace the coolant in the NT. The drain bolt at the pump seems to drain all the coolant.

My service manual is marked up so I don't go looking for the "crankcase drain bolt" the next coolant change.

Yes it does exist but would make a big mess by removing it. The way to do that is to drain from the water pump, and then if so inclined remove the crankcase drain after. I just drained from the water pump. All but a very small amount of fluid came out. No big deal as the old coolant was clean. I just replaced with Honda Auto Coolant, 50/50 mix. (Half the price of the Honda Motorcycle shops for the same stuff.) Honda coolant is blue in color. I figure the new coolant will dilute any small amount left in the system. This time I did not pull the radiator, but the next coolant change (around the 50k mile mark) I will R&R the radiator so I can clean/rinse it out.

PS: I just flipped the washer over and will look for a new replacement for next time.

 

[bicyclist]

I don't think that the "crankcase drain bolt" between the cylinders exist.

I agree with Dan. The only drain bolt is the one on the pump. I don't replace metal washers unless they appear to be worn/deformed and I've never had a leak.

edit: Well, Chuck posted while I was writing my post. That second drain bolt is located on the right side of the engine and, as Chuck says, will make a mess for no great benefit.

I also used the Honda car coolant.

 

[dnktng]

I agree with Dan.

Big mistake, he is an idiot, I know him.

Yes, the bolt exist, but I didn't remove it to drain the coolant. Some have said that the washer is part #18 on the crankcase drawing.... not sure myself, the drawing doesn't show the bolt. But like others have said you can get all the old coolant out without removing it. Squeeze the hoses, rock the MC back forth, burp it like a baby.

Sorry about the misinformation.

 

[Rmcapozzi]

It's time for Traveller's first cooling system service. In reading the manual, Honda recommend replacing the tow sealing washers on the drain bolts at the cylinder and water pump. I believe the water pump bolt sealing washer is a Honda p/n 90463-ML7-000, but I'll be darned if I can find the parts diagram that shows the sealing washer for the cylinder. Does anyone have these p/n's?

Mike

The service manual is incorrect on that cylinder drain location. See the thread I started here last year. http://www.nt-owners.org/forums/showthread.php?3617-Coolant-change-and-service-manual-error

 

[seagrass]

I removed the cylinder drain bolt and no coolant came out but a little oil did!

I then read the above thread and realised that it was not a coolant drain bolt at all.

The copper washer on the water pump drain bolt is a primary seal and care should be taken to ensure that it seals correctly when replaced.

If you are not going to replace the washer as advised by Honda do what I do and anneal it. This is done by heating it over a gas flame until it is cherry red in colour and then letting it cool. This will soften the washer so that when the bolt is tightened the copper washer will deform and provide a good seal.

 

[DirtFlier]

Both the water pump drain bolt and crankcase drain bolt are 6 mm thread so most likely the same sealing washer is used for both.

 

[seagrass]

Both the water pump drain bolt and crankcase drain bolt are 6 mm thread so most likely the same sealing washer is used for both.

One washer is copper and one is aluminium so I think they will be different part numbers

 

[Enty7]

Hi All,

Am busy with the coolant replacement.
Thank you all for the informative posts on the subject.
In my ignorance, I was expecting to see a "dedicated" water Pump drain bolt.
All I see are four mounting bolts (see attached photo)
My logic (?) tells me the drain bolt will be the one at the Bottom Front (7 o'clock position).
Please advise if I am on the right track.
Thank you.
Enty7
South Africa.

 

[DirtFlier]

[My logic (?) tells me the drain bolt will be the one at the Bottom Front (7 o'clock position)]

Yes, that's the bolt with the sealing washer, 90463-ML7-000.

 

[Rmcapozzi]

The bolt labeled as "3" is the drain bolt. That is the only drain bolt for the coolant system. Disregard the service manuals reference to a second drain bolt on the right side of the bike.

Hi All,

Am busy with the coolant replacement.
Thank you all for the informative posts on the subject.
In my ignorance, I was expecting to see a "dedicated" water Pump drain bolt.
All I see are four mounting bolts (see attached photo)
My logic (?) tells me the drain bolt will be the one at the Bottom Front (7 o'clock position).
Please advise if I am on the right track.
Thank you.
Enty7
South Africa.

 

[Enty7]

Hi All,
Thaanks for the replies.
Will procedd and advise!
Regards,
Enty7
South Africa.

 

[bicyclist]

Bolt #3 is the one you want.

 

[Enty7]

Hi All,
Successfully changed radiator coolant.
Thank you all for your input.
I am sure the next coolant change will not take as long as the first one did.
Attached please find a revised photo with the water pump drain bolt highlighted.
Thank you.
Take care,
Enty7
South Africa.

 

[gowman]

Quick question. I stopped by my local bike shop looking for antifreeze for my NT and they recommended Motul Motocool Expert. My bike has a little over 7000 miles and all I'm attempting to do is top off the reservoir tank. Has anyone used this antifreeze before along with the factory installed stuff? Thanks again

 

[bicyclist]

Quick question. I stopped by my local bike shop looking for antifreeze for my NT and they recommended Motul Motocool Expert. My bike has a little over 7000 miles and all I'm attempting to do is top off the reservoir tank. Has anyone used this antifreeze before along with the factory installed stuff? Thanks again

I haven't used it, but if all you're doing is topping off the reservoir, just use a little distilled water. A simple top off won't change the amount of antifreeze protection by enough to worry about.

When I flushed my cooling system, I went down to the Honda car dealer and bought a gallon of Honda Genuine Long Life Antifreeze/Coolant Type 2 for around $19. It goes for about $8 per quart at the motorcycle dealer.

 

[dnktng]

I stopped by my local bike shop looking for antifreeze for my NT and they recommended Motul Motocool Expert.

Is it silicate free? If is not silicate free...no, don't use it. To be safe, just use Silicate Free Antifreeze. It's cost about the same as most any other coolant, just harder to find.

My limited experience with silica control at my job tells me that silica is not always 100% distilled out in some distilling processes. Silica is a big concern because it doesn't behave like most elements that are normally removed by distilling, so we continually analyze for silica in our pure water. There is always some silica in it even after distilling and de-ioning. De-ionizing removes most silica, but not all. Most likely if there is any silica in store bought Distilled Water, it is small and wouldn't hurt anything in your NT if used to simply top it off for small amount of losses. But at some point the coolant should be changed anyway (every 2 years), so buy some Silicate Free Coolant and use it to top off your coolant.

mmm, I may take my Distilled Water jug from home to work and analyze it for silica, just to give myself something to do a 3:30am when I'm bored, tired, and sick of coffee. I've already analyzed fresh and burnt coffee for acidity. Burnt coffee really is more acidic....no wonder it wrecks my stomach.