proof of water pump leak

Have had a small coolant weep for the last few weeks. These pictures are after a 1000 mile weekend and the engine cleaned prior to leaving.
Would this be definitive proof of water pump seal leaking? Seems to correspond well to the location of the water pump weep hole. No leak evidence anywhere else above that spot.
This did not drop the coolant level at all over the four days, and the temp gauge acted normally.

I think that's the only explanation for a leak originating from that spot. Either that or a leaky timing belt

That looks to be a pretty major leak there, so I'm surprised the level didn't drop (I trust you mean in the overflow reservoir). Could also be the water pipe seal, under the carbs.

A leak of that apparent magnitude, if from the water pump, may also have contaminated the timing belt.

Dean, have you been able to look at the weep hole? Remove the black metal cover over the oil cooler hoses and confirm that the coolant leak isn't from the bypass hose to water pipe connection, nor the oil cooler hoses connections to the water pump and water pipe. Would an 'inspection mirror' help?

John

Bush said:

Could also be the water pipe seal, under the carbs.

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would that flow towards the back of the engine, like you get when the hoses/O-rings under the carbs fail? Can't recall what the consensus is on that or the bypass hose that attaches to the water pipe. Do they flow to the front?

Without removing the carbs, I've about eliminated all possibilities other than water pump, just hoping for some other mysterious source. All hoses etc etc were done a year and a half ago with the timing belt. So glad I needed to save the cost of the water pump while I was in there. not

The coolant level has not dropped in either the overflow or the radiator. Just a messy looking minor green spitting I guess.

The weep hole is kinda hidden John. Can't really visualize it actively 'weeping', but that's the spot. Oil cooler hoses look fine, as does the water pipe.
Done yours yet John? Is this the correct part # 19200-MY3-010

dwalby said:

would that flow towards the back of the engine, like you get when the hoses/O-rings under the carbs fail? Can't recall what the consensus is on that or the bypass hose that attaches to the water pipe. Do they flow to the front?

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elbows/o-ring leaks to rear....99.9% of time, as normally does the little by-pass hose.
BTW, getting to 'crunch time' Dean.......keep me posted!.

Haven't done mine yet, Dean. Two minor medical issues but I'll be on it soon.

Yes, that's the right part number.

John

Brant said:

BTW, getting to 'crunch time' Dean.......keep me posted!

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That's for sure Brant. Will do.

Dean, I would first suggest cleanin that slimy antifrezze off(BrakeKleen, then soapy water) compressor blow dry area and let set overnite or a couple days, then look for a seep around that gasket mating surface. The frontside wind has obviously blown that crap everywhere, so impossible to acually isolate at this point. I sure would'nt comdem water pump itself or associated weep hole at this point!. Personnelly, I'd be 'red-flagging' mating surfaces first.....and if that being the actual case, would'nt even concern myself with it(just aware,occassionaly checking coolant level) for the westerly ride, unless for sure you can change out whatever needs to be done prior. JMO, but you know what they say.

Prior to this last trip, I had been thoroughly cleaning and subsequently checking everyplace I could for a week or two. Not sure what mating surfaces you're referring to Brant, but all else seems ok. Without actually seeing anything coming out the weep hole (I'll be looking again), that's where it's coming from.

At least it's running great, as usual!

DeanR said:

Prior to this last trip, I had been thoroughly cleaning and subsequently checking everyplace I could for a week or two. Not sure what mating surfaces you're referring to Brant, but all else seems ok. Without actually seeing anything coming out the weep hole (I'll be looking again), that's where it's coming from.

At least it's running great, as usual!

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Running good is always a good thing......you didn't expect any less from the STeed, I'm sure.
Shoulda' been more specific, sorry.
I meant as in don't ride it. Clean it spotless, let it set for a day or two and watch for any wet place around the pump mating surface to block.......still nothing noted(touch mounting area for any wet place on your fingers), THEN start it, let it get warmed up to operating temp. while checking AGAIN for any wet spot around mating surfaces. You almost have to be anal particular doing this kinda 'pin-pointing', havin' area FIRST super clean and dry. If coming from weep hole(which I highly doubt), you would have IMO, seen a a loss of coolant with those miles when I presume doing the XSeast thing, as cooling system likely would not of held pressure well.

Brant said:

watch for any wet place around the pump mating surface to block

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Is there not a radiator and timing cover in the way?

DeanR said:

Is there not a radiator and timing cover in the way?

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Heck if I know Dean...I'd have to go look. Was just gong by your pics, and I guess un-knowingly assumed things were visible when together and running. That's what I get for owning such a trouble free scoot (cept for the 'coolant elbow/o-ring' issue).

John OoSTerhuis said:

Yes, that's the right part number.

John

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Do the o-rings come with the new pump John?
Any other parts need to be ordered? (other than tensioner and idler)
Did you use Partzilla? looks like the best prices if my dealer won't come close.

DeanR said:

Do the o-rings come with the new pump John?
Any other parts need to be ordered? (other than tensioner and idler)
Did you use Partzilla? looks like the best prices if my dealer won't come close.

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on mine ('97) the pump came with an o-ring, but it isn't advertised that way on the fiche AFAIK. I bought the o-ring separately and didn't need it.

Yes, the big o-ring should come already installed with a new-stock pump. I ordered the oil seal and gasket for the left cam pulley in addition to the timing belt idler and tensioner pulleys.

I used my good dealer for my timing belt and water pump parts, except for the genuine '91 new-stock pump that I got from Tim Shelvin a few years ago. I'd look at Service Honda and Ron Ayers in addition to any other online source.

Brant said:

...start it, let it get warmed up to operating temp. while checking AGAIN for any wet spot around mating surfaces...

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I second this...
Personally am I not convinced about a w/pump issue, cause by traces it appears as a way too large leak... (unless the mains O-ring of the w/pump case is decaying...)

When the mechanical seal gave in on my (prev) '92, was there not more then like a teaspoon of liquid on the ground for the first 1~2 minutes right after starting the cold engine; after that one couldn't spot any seepage anymore as the small amounts just evaporated on the warm engine case before getting visual...
Parallel I needed to top-up the expansion tank with ~1/8ltr every week or two...

Those large "stalactites" shown on the pics would indicate quite a big leak...

Brant said:

start it, let it get warmed up to operating temp. while checking AGAIN for any wet spot around mating surfaces.

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ST1100Y said:

I second this...
Personally am I not convinced about a w/pump issue, cause by traces it appears as a way too large leak...

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Again confused about what mating surfaces are you guys referring to.

The pictures are cumulative leakage over a thousand mile weekend. NO topping off of coolant was necessary. Radiator and overflow tank is at proper level. I figure that means it's a much smaller 'weep' than the nasty looking pictures depict.

Only other thing I can do, I think, is pull the carbs, to I suppose check the bypass hose connection. But the water pipe is clean of any stains and is that not where it would run down? But no leakage to the rear, after replacing all hoses a year and a half ago, so I believe everything to be ok under the carbs.

Below is a picture of a slight oil drip that I noticed at about the same time the coolant appeared.. Don't know how that could be related.
and
a picture of where there is coolant stain ABOVE the weep hole (outlined but cleaned in this picture). Don't know if it would have sprayed up there or not.

Did you replace the oil cooler hoses as well? The way that coolant has spread "far and wide" seems to indicate a possible spraying of coolant and, being most heavily concentrated around that cooler hose, is it possible there is a small tear in the hose that leaks under pressure? I would clean it all up then idle the bike for quite a while to build pressure and heat in the cooling system and see what might show up.