675 coolant leak help!!

Sorry Dave cant help, but pictures help more than words ever will (if possible to take and show the problem)

 

Hi Dave, first of all let me welcome you into the Triumph Asylum - you'll soon see why .

Now, about this leak problem, I'm not familiar with the exact layout of your bike but I would like to try and diagnose with you, what's going on?

It sounds like your radiator cap/thermostat might have gone west and allowing coolant to pass out of the system via the overflow pipe. It also sounds like the spigot (the bit that the overflow pipe fits onto) is snapped off.

Can you get some pics posted so we can see if that's what is happening?

 

................and went out of the boiling water shuts again

 

(I have a Speed triple so may not be the same as the Street Triple - just realised htis after posting the below)

When you say top right, is this as you are sitting on the bike?
As the cap is on the top left when you are sitting on the bike and also has the small hose which leads to the expansion tank routed under the seat
If it is leaking from the cap, this has happend to me on my '10 Speedie. I replaced the cap (£5 from Square Deals IIRC) but it did leak when there was collant in the hose that led to expansion tank, I think it has a syphoning effect. So when I took the radiator cap off, I would have the front wheel in the air so the radiator is higher than the expansion tank, I would completely fill the radiator, making sure to squeeze the pipes as the bike warmed up to get as much air out as possible. As the coolant starts to rise due to expansion I would put the radiator cap on so there was no air in there at all. I would hten lower the front wheel and top up the expansion tank. I didn't have any leak after this.

If your radiator cap really is bust, it could let air in which expands and pushes the pressure up until it leaks out in an rather impressive way..check out my vid here for what happened to me

If the hose attachment is cracked/broken, hten it may be a case of a new radiator unless you can find another way to secure the hose on securely.

I would be hesitant about using sealant, because if this gets into the coolant, and thus into your radiator, it will block up the channels and reduce efficiency.

 

When you guys say thermostat, I presume you are refering to the radiator cap with the valve that opens and closes depending on the coolant pressure in the radiator and not the temperature, just want to clarify this for the OP
As there is a thermostatic valve that opens the coolant system up to the radiator when the coolant reaches operating temperature, to aid warming the engine during start up....

 

Definetly sounds like the seal on the radiator cap has failed if it is leaking when it reaches temperature.
Maybe a blocked hose to the expansion tank, as air or coolant should pipe through to the expansion tank when the pressure builds up, any air would be replaced by coolant as it cools down and the coolant compresses causing a vacume.
Top tip: when you get your new cap, use the opportunity to replace the coolant and when you put the cap on, wet the rubber sealant/valve with coolant to reduce the chance of the new cap seal tearing/splitting when being put on.

Do ensure there is as little air in the system as possible, if you can, get the front wheel in the air and maybe have the bike slighly tipped to the right (as you sit on it) so that the valve cap is the highest point o the system.
Keep the cap off and start the bike, squeeze the pipes to expel the air and keep topping up the coolant. When the coolant starts to expand, then put the cap on as it reaches the top. There may be some spillage but there would be as little air as possible in the system.

Search on YouTube for Street Triple coolant change as there are many good guides on there

 

You're absolutely right RT I was confusing the 'stat and the rad cap - but I meant the rad cap

 

Street triples do have rad failing problems, also make sure when you have found and sorted the leek to drain and refill the system with the correct Triumph coolant as it could be that another person has put normal glycol antifreeze in it

 

I use Castrol motorbike coolant. - The blue stuff.
I tried Evans waterless, but promptly went back to the blue stuff as the Evans stuff was thicker, put a strain on the pump and actually ran hotter.
I have also reduced the temp at which the fan kicks in to 95c so it comes on before the water starts boiling, it certainly helped keep the engine cooler this summer in the London traffic

 

Glad you have localised the problem, hope it is a quick fix.
When you take the old cap out, take a look at the rubber seals, there should be two, a lower one on the spring loaded plunger thing, and another at the base of the cap wich seals against the radiator lip. There may be a hairline split, or even jsut a hair caught between the seal and the lip which would allow the spill

Good luck and let us know if it gets sorted with a new cap

 

Yes it would. If the spring or the seal in the cap have got tired they would not hold the coolant, when it expands due to heat, so the coolant forces itself past the seal on the spring part and out the overflow.

 

If you are 100% sure the coolant is leaking where the hose connects to the radiator then that is a seperate issue, either the hose has deteriorated or the connection has fractured (I think you mentioned this in an earlier post)
If the radiator connection has fractured then either you would need to try and connect the hose securely, move the hose as far up the connection as possible and tighten the clip to ensure a seal. If this is not possible then it may well be a case of replacing the radiator..ebay, square deals, world of triumph, local dealer etc...

If you can, remove the hose and post a quality picture on here, maybe we can help out and see something you have missed. But this would lead to losing some coolant...
But definitly pictures here. With or without the hose connected

(Save the picture onto your computer, then in your post click the 'Upload a file' button next to the 'Post Reply' button, select the images and let us help)