And Another Coolant Leak

ST Gui · Aug 27, 2016

A buddy has what I say is a coolant leak coming from behind the housing that's attached to the bottom of the hose in this pic:

Coolant can be seen in the grove between the two pieces in the upper part of the pic. He's not so sure. He says it's not coming "from above". A local dealer has been through the coolant system once and this leak may be on them to fix. The ST has about 100,800mi on the clock. What say you?

Blrfl · Aug 27, 2016

ST Gui said:
He says it's not coming "from above". What say you?

I say it's a better bet that it is coming from above and that it's a lot less work to check that out than to pull the water pump and find out that was actually the case.

--Mark

970mike · Aug 27, 2016

Take a look at which hole the coolant is coming out of, the small round hose would be the water pump, the larger square hole would be something up top under the throttle bodies. Your picture does not show those as they are on the back side of that hose.

Good luck.

BakerBoy · Aug 27, 2016

That is a coolant leak from above the engine at the thermostat housing or associated hose connections--it drains through a passage behind the water pump and oozes out at various places along the edge of the water pump housing.

The following is my bike...

This first picture shows the dried coolant all along that water pump housing, the rectangular hole that drains most of the coolant that leaks from above the engine, and it also shows the small round hole which would drain any oily coolant should the water pump seal be leaking.

The second picture shows how much mine was leaking from connections above the engine (only when the engine wasn't up to temperature). The leakage mine had is commonly mis-diagnosed as a water pump seal failure. All of this leaking was solved on mine (and on other bikes) by addressing the coolant hose connections above the engine.

Edit: 2008 and later models have a metal nipple and drain tube in the place of the small round hole shown in the above images. For 2008 and later, it is clear to see that any coolant on the outside of the water pump housing would be either a catastrophic failure (as if the entire seal somehow leaks!) or just said drainage of coolant from connections above the engine.

Igofar · Aug 27, 2016

ST Gui said:
A buddy has what I say is a coolant leak coming from behind the housing that's attached to the bottom of the hose in this pic:

Coolant can be seen in the grove between the two pieces in the upper part of the pic. He's not so sure. He says it's not coming "from above". A local dealer has been through the coolant system once and this leak may be on them to fix. The ST has about 100,800mi on the clock. What say you?

I think you should refer your buddy, to your other buddy :rofl1:

With that kind of mileage, it could be hoses, clamps, fittings, O-rings, or the water pump seal.
Your buddy would have to see it in person to be sure.

ST Gui · Aug 27, 2016

Igofar said:
I think you should refer your buddy, to your other buddy

I tried again today when we were looking at the bike but no dice. It's just too far for him and he uses the bike every day. He can walk to and from the dealer when that's necessary.

BB thanks for the pics. I'll show them to him asap. Everybody thanks for the info. I'll talk to him tonight.

ST Gui · Aug 27, 2016

Dialing the white courtesy phone now...

slmjim · Aug 28, 2016

BakerBoy said:
That is a coolant leak from above the engine at the thermostat housing or associated hose connections--it drains through a passage behind the water pump and oozes out at various places along the edge of the water pump housing.

The following is my bike...

This first picture shows the dried coolant all along that water pump housing, the rectangular hole that drains most of the coolant that leaks from above the engine, and it also shows the small round hole which would drain any oily coolant should the water pump seal be leaking.

The second picture shows how much mine was leaking from connections above the engine (only when the engine wasn't up to temperature). The leakage mine had is commonly mis-diagnosed as a water pump seal failure. All of this leaking was solved on mine (and on other bikes) by addressing the coolant hose connections above the engine.

Edit: 2008 and later models have a metal nipple and drain tube in the place of the small round hole shown in the above images. For 2008 and later, it is clear to see that any coolant on the outside of the water pump housing would be either a catastrophic failure (as if the entire seal somehow leaks!) or just said drainage of coolant from connections above the engine.

Good explanation and very good pics. Should be a sticky in Tech.

Good Ridin'
slmjim

And Another Coolant Leak

ST Gui

240Robert

Blrfl

Natural Rider Enhancement

970mike

Mike Brown

BakerBoy

It's all small stuff.

Igofar

ST Gui

240Robert

ST Gui

240Robert

slmjim

Hopeless Tool Junkie