Came back from a ride yesterday and just as i stopped, bike dumped about a litre and a half of coolant out the overflow pipe. Neither day nor bike particularly hot so am at a loss to know why this happened.

Is it a precursor of something potentially serious ?

Do a search on here for "radiator cap".

I'm betting that's your problem.

Look for dirt or crud or damaged seals. 

Could be you need gaskets or a new cap, I'm thinking.

Have a look here...post 34 onwards may help.

yep.... blakeys on it  

likely to be air in the cooling system

when you stop it goes everywhere

check out the thermostat too I have seen a couple that didn't go full cycle open

tks for that - will check out all that.
Charlie are you coming round pre or post christmas.

Obviously, if its pre, then you will get you fairing done up in Chrissy paper.

I guess will be post Christmas mate ....

old gerty took me a day of so longer than I expected ...all the heat around during the mid day hours ...too much to be fun

do you have things planned in between ?

thinking boxing day at this moment ...as I missed my opportunity to make mums before Christmas ...blast

let me know when is good  ( be in the rolla ...but plan a ride down as well )

PM'd you

I just want to top up the coolant but i take it that I have to remove the tank to get at the filler cap and the reserve tank, which means that I'll have to remove the fairings (being an RS).
Correct ??

This seems to be a major job just to add coolant and i need the bike for the morning. Wah.

if your going into do the coolant

don't forget to install slightly longer fuel hoses (especially on the rear hose ( fuel feed and high pressure )....about an inch or so does the job ....then you can lift the tank without having to undo anything else (other than the side covers ) ...to get to the filler

but try it anyhow you might just be able to get at it ...careful how you go if you crack a hose could be a fire soon after ...

good luck

Right hand sidecover to access the overflow tank. remove the right hand inner fairing cover, lift the rear of the tank and slide it back to access the radiator filler cap. make sure the bike is on the centrestand first.

Removing the fairing would be way over the top.

Al

don't forget to remove the lefthand side cover also ....it holds to the tank and will break the connection pin  if forced

so thats both sidecovers before lifting the tank to move it back ...\\

cheers

tks too Charlie,

can't do anything about the length of the hoses tonight, but i will modify soon.

Seem to remember reading a post about the need to use a special hose - is this the case.

What happens if i just remove the RHS side cover and top up the reserve tank (ignoring the main cap) and just take some coolant with me and check it 10kms down the road and add more if necessary.  Stupid idea??????

but wait there's more 


see above

werewasi wrote:What happens if i just remove the RHS side cover and top up the reserve tank (ignoring the main cap) and just take some coolant with me and check it 10kms down the road and add more if necessary.  Stupid idea??????

The normal way of topping up is via the coolant expansion tank. The main cap is used when initially filling the system (empty radiator).

Using the expansion tank to top up your coolant will work, providing you didn't lose too much coolant when it dumped.
When I had my coolant saga (Blakey gives a link to my post on the issue...but my saga starts here https://www.k100-forum.com/t8299-radiator-pipe-suckage#97366), that is exactly what I did. I was on the road, over 120 miles from home so stopped off at a service station and bought a bottle of coolant/antifreeze mix - diluted it with water using a discarded drinks bottle (don't you feel special when you go bin diving!!). I reached my destination (10 miles further on) and once the bike had cooled, topped up the expansion bottle again. I did the same again before riding home the following morning.

However, if your main cap is not working correctly (i.e. not allowing the radiator to suck fluid back from the expansion tank as the water cools and/or not allowing excess water to vent to the expansion tank as the radiator gets hot and the pressure increases), you may continue to have problems. 

Good luck.

best to check the filler

if there is a fair amount of air in there ...It will happen again

air expands more than water ...

also confirm both rubber seals are in the cap ...mine wasn't   but a oring did a fill in job till the right part arrives

just what makes sense to me

the pipe should be "fuel injector line"  8 mm  ...   30 r 7 is the minimum standard   30 r 9 preferred  the best is 30 r 10   but the last 2 wont be stocked by supercheap  et all   a foot will do it

hope that helps

tks B A E,
will try just filling expansion tank and see what happens 10kms down road. If level drops, then presumably radiator is sucking it back (good sign) and i can just retop up.

OK Charlie, hear what you are saying and as soon as i get home, i will pull tank and check rad cap.

the coolant will replenish from the expansion tank when the engine is cooling so the best thing to do is start the engine and run it till very warm and then fill the expansion tank and as it cools it draws coolant from the expansion tank but as BAE said the seals have to be good.

Rick, 
Topped up the expansion tank and went for a 10km ride. Just got back and am letting engine cool so will check exp tank first thing in the morning. As you say, if seals are Ok, it will have sucked coolant out of this and i will top up again.

I've noticed the filler cap washer can get compressed on one side. Try turning it over as a temporary measure till you can get a replacement.

Now AUS day w/end and coming back to Sydney from Bob's at Robertson, I got caught up in the slow traffic in the M5 tunnel and the temp light came on. I had no choice but to keep going and pull over when i got outside to a bay on the eastern side. During the weekend someone had switched a fan on, and so I knew i didn't have one (operable).
It dumped all coolant fr reservoir before I could get the cap off so now I suspect that i actually have had a loss fr the radiator and so I'll check.

What is the correct coolant to use as replacement and would tap water be OK given that as soon as I get home I'm going to drain the radiator as part of the process of determining why the fan is not engaging.

Got a guff sheet fr Bob on how to isolate the cause.

On second thoughts why the need for green coolant if I'm just going to drain it 700kms fr here. Why not just water since I will be dumping it, and I'm facing a cool ride home in showers.

It shouldn't hurt to use tap water to get you home, but don't forget that coolant has a much higher boiling point.

tks.
Should have engaged brain and thought of using the stuff that is falling out of the sky at the moment and will continue for a day or two!!!!!

Took radiator cap off. No sign of water !! might have been very lucky. Surprising that I didn't get the red light again.

I want to head home but the Nth coast forecast is bad - heavy rain till wed. Rode down in the wet. Over it - truck spray and misty visor thing. Used tyres off my other RS - age uncertain though they look good.
This is meant to be the middle of summer !!!

Any pointers as to the ratio of coolant to water that I should be putting back as replacement later. Since I haven't got the Clymer here, Don't know if it's in the book. Recommended brand? type?

Dave
Pretty much any coolant suitable for alloy engines will do. I use Tectaloy. $6 from K-Mart


Their Mukowt Radiator Flush is also good stuff.


Radar is showing storms from Port Mac to Coffs atm 2:15pm That will move up the coast as the afternoon goes on.
Take it easy on those tyres

water will do dave  till you get home

then have a good look at all the seals in the cap .... we'll have to look at that fan connection - and under tank stuff (temp relay)

take it easy mate

Will leave here, Bondi Jnct. at 6am to keep out of traffic and moving faster.

Sheet fr Bob to test fan is good, thinks it came fr "How to....."   - 'jumper wire to connectors 15 and A2..... etc

Not good that I've been riding around with no fan since i bought it. Not surprising it overheated on the Bruxner Hwy on way to Smithy's that w/end.

I put an override switch on my fan and as soon as I stop in traffic I turn it on and even in winter I turn it on to check it works. I always check with a stick and give the fan a spin and not long ago found Margs fan on the K75 was cactus so I had to use the spare.
I bought a 9" one to put on chookie but so far haven't fitted it but I will need to move the radiator forward a touch.