My st 2004..Can you help me?

[Grimmy]

Good morning. Even my 2004 st started to leak coolant from the square hole. Actually the leak when it reaches the bottom of the hull is slightly oily. I saw that the coolant level does not drop dramatically and I keep it monitored. The thermostat and the water pump seem to work, even the temperature during operation is ok.

Can you help me?
Thanks
Christian

 

[Obo]

Welcome to the forum Grimmy.

It's hard to tell if it's coming from the hose or the waterpump seal is bad. Is it wet at all above the groove / square hole you can see the coolant in?

 

[ibike2havefun]

Remember that square hole is just the END of a channel that goes all the way across the front of the engine. The leak may well originate on the other side of the engine.

If it's been "a while" since you checked and tightened all the hose clamps, that would be my first suspect. ST hoses and clamps are known to loosen up over time, especially during storage in times with substantial temperature swings.

 

[Bikeric]

Welcome to the forum from Cornwall UK!

 

[Grimmy]

Thanks Obo and Ibike. Certainly the bike stopped a lot of time before I bought it two years ago and in 16 years it did about 30000 km. Last year I replaced by myself engine's oil, filter, air's filter, transmission's oil and brakes pads.This year I replaced brakes' and clutch's oil and I bleeded all the system.Then I decided to replace the liquid coolant.I followed the repair manual step by step. I disassembled and cleaned with salt the expansion tank that was very dirty.When I replaced the liquid coolant, a little went in the middle of engine.But the one that I see is cleaned liquid.So I don' t know what I can do.The bike does indicate nothing.Maibe somethig is loosening.It seems that,and here I answer to Obo, all the groove Is wet. I hope for the best.

 

[CELarson]

Welcome to the forum from the weST coast...

Is the leak only when the engine is hot? Was it leaking before you replace the coolant?

Cheers

Craig

 

[Grimmy]

It seems that it loses at first, with a cold engine. Then it stops. Before, with the old liquid, it lost very little, almost nothing. But I can't tell you exactly because I had never disassembled it before. Then the liquid does not seem to fall from the tank.

 

[Upt' North]

You need to get in there check the hoses and clean and dry everything off. Shouldn't take too long in the Italian sunshine. If everything has residual coolant and oil on it you'll be lucky to track it down.
Hope it helps.
Upt'North.

 

[Grimmy]

I really hope you are right. I don't know if I am able to do such a job because I have to open half a motorcycle. I do ordinary maintenance but this is another thing. I am a little worried. Entrusting a workshop okay but here in Italy only a few know the problems of this bike.Thanks.
Christian

 

[GGely]

Hi Christian, don't worry about your ability to get this done. There are all sorts of inmates here that will help you and keep you out of trouble... Tracking down the source of the leak and tightening the hose clamps etc. isn't hard and doesn't require much beyond a few hand tools.

Go slow, take lots of pictures, label things, ask questions and before you know it, you'll be done!

 

[fnmag]

As above, this forum will provide continual help until you sort it out.
Dig into it Christian.

 

[GGely]

 

[SupraSabre]

Welcome to the forum.

Looks like a lose hose in the valley, under the throttlebody.

This is what a leaking waterpump looks like:

 

[Grimmy]

Thanks.This is my water pump,after I have replaced the liquid coolant..

 

[ToddC]

Like others have said...loose hose clamps...or old clamps. Fixes 80%+ of all leaks on these bikes.
ToddC

 

[SupraSabre]

This is what that one looks like after a new waterpump/clutch.

 

[Grimmy]

I understand what you are saying....

 

[SMSW]

If you replaced the coolant, you had to remove the bodywork and the hoses from the radiator. Its only a little more work to pull the radiator off and then the horizontal stay across the front of the engine - this hides the thermostat housing. I found a tiny drip of coolant on the bottom of one of my bigger hoses on the 'stat housing, and sort of went all the way and replaced the OEM hose clamps that I could reach with Gates or Breeze clamps (you can do a search for these words in the search box - blue bar above, right end). A number of the guys here have said simply tightening the OEM hose clamps will solve your problem but don't over do it - they are narrow and can cut the rubber. And eventually they will leak again. If you find a drip, its a good idea to remove the hose (yeah, drain the coolant again) to check for corrosion on the metal spigot that goes into the hose.

 

[Grimmy]

Thak you very much.With this kind of problem I don't know if I must wait to do the work in the end of Summer continuing to go or stop It and do the work.I have just replaced the liquid coolant:I have drained It from the big hose of the water pump and through the screw with the copper ring,following the manual of repair.I could go on, but before I have to find the hoses to replace.I hope instead that I must only tighten the clamps.Greatings from Italy..

 

[fnmag]

Assuming it's just hose clamps that need tightening, you could wait until after the summer.