Major coolant problem

[Bofh_uk]

I managed to put a hole in the rad a few weeks back and had to use rad weald to seal the hole so I could get home. It was fine until the other day when I managed to put another hole in it due to the horn rubbing against it.

That hole sealed itself, I guess there was enough rad weald left floating about to do the job. Unfortunatly this morning on the way to work it went again, this time it was not coming out the rad but over flowing from the expansion tank and the temp went right up to the red line, I just managed to get to work.

The expansion tank is full and the rad looks empty. I have a spare rad and fan switch if needed but I'd rather like to figure out what caused this mess rather than replace the rad and switch especially if they are not at fault. I'm worried that it could be the thermostat and that looks like a real pain to replace.

Someone please help before I go mad

 

[The Big Red One]

You already sound a bit mad to me

 

[Bofh_uk]

You already sound a bit mad to me

I'm well on the way that's for sure, by the time I've fixed this pain in the arse I certainly will be

 

[Red05]

Air might have been sucked into the hole in the radiator and if so needs to be bled out. Fill the rad and tip the bike side to side as far as possible.

 

[mike1180]

I never liked that Rad Weld stuff myself.
It also goes throughout the engine and I can't see it not coating all those parts too, besides the leaking area. JMO

 

[Mr Bogus]

did not leak cause it was already too low? did you refill and burp the system?

 

[Bofh_uk]

I've been reading about the burping, when I had the first hole I didn't do it properly and the gauge did go through the roof until it was blead again. I might give it a try before changing anything else.

The expansion tank is full to the top right now so should I drain it back to the lower line before re-filling the rad and burping it?

 

[Wag]

Yeah, first things first when troubleshooting. Get all of the air out of the system. I don't tip from side to side, I just squeeze the hoses on both sides and keep topping it off. Then run the bike long enough to heat up the hoses and keep squeezing them until it's too hot to hold. Then run it a while longer and let it cool off. Most likely, when it's cool and you take the radiator cap off, it will still be topped off and you will have squeezed all the air out of the system. Better to do this with the bike vertical as in when you have it on a rear stand but it's not completely necessary.

If that doesn't solve the problem, then it could be anything else: Do a full system flush and make sure there is no crud in the bottom of the overflow bottle, then check the fan fuse, then the fan motor next, thermostat next.

You'll figure it out if you're methodical about it.

BTW, very risky to ride it with such potential problems. That's an expensive motor on which to be running stop leak products.

--Wag--

 

[Bofh_uk]

Many thanks for all the advice chaps, does anyone think it's worth replacing the rad while I'm at it as I have a spare, or will a good flush clean out all the excess rad weld.

 

[Bofh_uk]

Well fingers crossed things seem to be better, nearly. I drained and re-filled, burped the system although not too much air came out. I ran it up until the fan kicked in and then cooled her back down under half way on the gauge. The new hole in the rad from the other day sprang a small leak and then seemed to stop.

So I'm off down the shop to get a little more weld and close this hole off, I know its a risk but my mechanic mate seems to think it will be ok.

Fingers crossed she will be back up and running in a few hours for some testing

 

[Wag]

You have a new or spare radiator that doesn't leak? Why not make life easy on yourself and replace it?

--Wag--

 

[Mr Bogus]

You have a new or spare radiator that doesn't leak? Why not make life easy on yourself and replace it?

--Wag--

+1 and probably would not hurt to flush that crap out of the system while you are there..

Many radiator shops eliminate tubes to fix the leak rather than try to patch the leak (usually the best bet anyway). Depending on where in the country you are riding, it may or may not make a bit of difference..

my vote is fresh radiator if you have one..