Normal leak rates range between immeasurably small to steady drips or temporary to even small steams. Some seals leak some of the time, some seals never leak (measurably), and some leak all the time. Leakage patterns can be constant, progressive or erratic in nature.

This is where the Professor learned something, two days ago I'd never heard of a mechanical seal, now I've been schooled on them, very interesting subject.... and just a bit baffling.

I think the Hub and I are still mystified about your impeller cover looking so dark. Personally, I think its been etched by chemical attack (acid).

Cannot say for certain but my first thought was Kawi hard anodized the pump interior to prevent internal corrosion. Jury is still out on that one but it makes perfect sense.

* Last updated by: Kruz on 2/13/2013 @ 6:23 PM *

Water Pump, Electric, 35-37 gpm, Billet Aluminum, Black Anodized, Chevy, Small Block, Each
Estimated Ship Date: 3/18/2013 (if ordered today)

Mechanical seal leakage is affected by the parallelism of the sealing planes, angular mis- alignment, coning (negative face rotation), thermal distortion (positive face rotation), shaft runout, axial vibration, and fluctuating pressure.

"Even though these mechanical seal faces also require some (very small) leakage across the faces, to form a hydrodynamic film, this leakage normally evaporates and is not noticeable. Most pump shafts today are sealed by means of mechanical seals"....hence the weephole.You won't get much 'evaporation' with coolant liquid...but it will sit in there and age(not having direct exposure to the air outside that case).JMO.

"a check on ZX6R.com turns up no one else with this problem on an '09-'12 model"....pretty convincing I'd say.

I think you were wise to give it another shot.I do believe your problem is a non-problem now .

* Last updated by: Grn14 on 2/13/2013 @ 9:02 PM *

Not so fast Grn, I've been doing my homework on the subject. It is a very common occurrence for a waterpump in the early stages of mechanical seal failure to exhibit an intermittent seepage of coolant from the weep hole. I Googled this and saw numerous examples of start and stop coolant leaks. I think it's time to rebuild my pump. My question still stands, why did mine fail at 7000 miles and no one else's I can find?
These things are designed with a much higher MTBF than 7000 miles.
The only time I've experienced a waterpump failure on an automobile waterpump was due to internal bearing failure, excessive wobble (runout) of the shaft. Seals can't seal under those conditions.

@Hagrid...you were right about the black corrosion in the pump chamber, quote from excellent VW/Audi factory website:

Image 2) Water pump removed from a Vw 2.7T with less than 3,000 miles due to leaking. It was wrongly assumed that it was a manufacturer defect. However, the evidence revealed that the leak was caused by coolant contamination. Note the abnormal black discoloration of the aluminum casting. The cause was a result of an additive (likely a flushing agent) containing muriatic acid/other acids being used (before or after the water pump replacement). Acids left in the coolant system ate away at the internal seals and caused premature water pump failure.

Hub, who puts the coolant in our new bikes when they prep, factory or dealer?

The factory tops off the coolant.

Your hand is at the bottom hose, and any hose you can find, then squeeze it as you keep filling the coolant back up. This 'burping' pushes air bubbles out as you fill. If you don't, the air pocket would fill later, the level would drop, the air would displace the water and now the bike overheats having less water to do its job.

This is a interesting thread. Did the coolant in the radiator appear to be factory-fill? The discoloration of the aluminum pump body is a sign of reactivity between oxygen and phosphorous which could be caused by a leakage of motor oil into the coolant and the leaking seal. Does the radiator also display the blackening of the aluminum?

Just as a experiment it would be interesting to soak the blackened aluminum body in a 50/50 mixture of white vinegar (apple cider vinegar) and distilled water heated to approximately 140ºF. A short duration of 10 minutes should suffice to convert the anodized metal back to silver.

I wouldn't be surprised if corrosion is what lead to the pump failure.

It's always been my understanding that trapped air in a pressurized cooling system causes overheating because the air is compressible, so the temperature goes past normal before the system can develop the proper pressure. At that point, emulsified air causes boiling and the coolant can't do it's job.

The discoloration of the aluminum pump body is a sign of reactivity between oxygen and phosphorous which could be caused by a leakage of motor oil into the coolant and the leaking seal.

Those pics were off an '08, not my '09, same pump design however, I don't think Kawasaki ever re-invents the wheel.

Yes, that pump was most likely damaged by contaminated coolant, one site identified muriatic acid radiator flush as the possible culprit. His oil cooler had an internal crack and leaked oil into his coolant and probably vice-versa. He pulled the waterpump off mistakenly thinking that was the issue.

Jury is still out on my problem, I ran it again with a rolled up paper towel uder the weep hole earlier and got more liquid so it's going to have to come apart. The color was a pale yellow with a greasy feel, most likely coolant although when I gave it the sniff test, it smelled distincly petroleum, almost like WD-40. Ethylene Glycol coolant normally has a very sweet, distincitve odor. This smelled more like old worn out motor oil but it wasn't dirty like motor oil so must be coolant, possibly contaminated by something else.

Could the factory have messed up and used the wrong coolant on mine as original factory fill? I'm trying to think what else could have caused a water pump seal failure in so low mileage.

Another clue, I noticed a peculiar odor coming off the bike last night, not the sweet, maple syrup smell of burning antifreeze but some other smell I couldn't identify.

Hubster, need your expertise again. Why does Kawasaki come out with a new part to replace an old P/N?

I went to order the rest of my parts including a new waterpump housing this morning and lo and behold, Kawasaki replaced the old waterpump impeller just this morning with a new P/N.

Look it up on the link to the IPC I posted below,here's the note:

59256 IMPELLER 59256-1074 Replace With 59256-0555

What gives here, why would they do this and more important could there be a problem Kawasaki is not talking about but quietly replacing the parts?

I went ahead and ordered the new impeller just in case.

Your thoughts?

* Last updated by: Kruz on 2/20/2013 @ 6:42 PM *

http://www.kawasakipartsnation.com/oemparts/a/kaw/500b77ccf8700223e4798af2/oil-pump-oil-filter

The impeller carries the porcelain rotating portion of the seal, coincidence?

Kruz: I know you cast this out to the Hubster but I have a thought.

Its important to ascertain what exactly changed between the two part numbers. Could be a revision of the sealing tech... or simply a revision to the shape of the vanes.

A side by side comparison would yield the most results I would think.

Those were my exact thoughts Hagrid. If they changed the vanes, I can think of two reasons, improved coolant flow or reduced vibrations. If you look at the design of the mechanical seal, the rotating seal face, porcelain rests in a rubber cup on the back side of the impeller. The fixed seal face and preload spring are pressed into the pump housing. The thickness of the impeller would determine how much pressure is applied to the seal surfaces which would effect wear rates and leak rates. The impeller is mounted out on the end of a skinny pump shaft, about the diameter of your pinky finger. If it vibrates, then the seal being attached to it, is going to leak. This story is starting to get interesting, there's a reason KHI redesigned that impeller. As soon as the rest of the parts arrive, I can pull the old stuff off and make a comparison. I was talking to Rook earlier and he agrees, KHI only changes parts like this out when there is a safety related issue but they never advertise it!

* Last updated by: Kruz on 2/20/2013 @ 8:31 PM *

Kruz: I know you cast this out to the Hubster but I have a thought.
Its important to ascertain what exactly changed between the two part numbers. Could be a revision of the sealing tech... or simply a revision to the shape of the vanes.

Both Seal P/Ns are unchanged, only impeller P/N is different. More telling, the old P/N is no longer available.

* Last updated by: Kruz on 2/20/2013 @ 8:38 PM *

1. Build one 'Top shelf' model. Now, the day after it is built, the drawing board improvements continue to improve the breed.

2. 'Field Fix.' This is where warranty complaints zero in on a certain areas (water pump leaks) of the new bike as well.

3. 'Forced Designing.' Improve the breed of the drawing board designers. This is an exercise to bring up the up and comers or lead designers. So the pool takes a look at the bike, redesigns that flimsy air cleaner cover you complained about. The ABS was a given since day one of the bike's introduction. We were introduced to the kskid as part of the upgraded package. So the design is to present a different body panel to the bike. Different crank rods for more HP.Present the bike without abs or present the bike with all add-ons as designed. How the close fitting brake lines hug throughout the bike. Improve the subtle lag at the sub plates we all complained about. Force that problem onto the designers and come up with a solution.

Like hag said, it's the side by side subtle changes that change the part number. Take harley's part number for example. I'm chasing a part that is part number ****-15. It's a transmission keyway for the output shaft. So, in 1914 they changed the bike mid-year, right? So as this part is going to be used forever just about, they still use the same part number, but now it reads with the improvement or updated number/letter designation. It might be who the jobber change? It might be a color change? It can interchange with the old one either way. Being, the part is not that drastic of a change, if X and Y still hold the same clearances for the part to fit. Now, whatever improvement they changed, it now reads pt.# ****-15A. Did they cut the key at the bottom so it has 3 cuts rather than have a half moon look to it? It still fits down into (X) the key slot. It still has an interference fit at the side (Y) of the shaft's key slot. So what could have possibly change?

If you search another wet bike, look up that mech seal, you'll see a square block around all the parts that come as a kit. In this case, Kruz, someone who drew that page, missed that part, or sometimes they leave out parts to keep the page looking less cluttered. My guess is someone plain missed that block to show you the porcelain comes in (as I remember) a kit. It has the spring'd cage, the rubber insert boot for the back of the impeller, and the porcelain washer. As far as the impeller, it could have less blades, more blades, less pitch, more pitch, grew a half a millimeter in size but still fits inside the housing. Until you see the difference, we have no clue but to guess?

Hub, I have the parts here I ordered last week, the rubber cup and porcelain washer came with the mechanical seal cage. I see that blue goop on the sides of the cage, sealant of some type.

The porcelain looks more like hard plastic to me but I may be wrong, the gray polished fixed surface in the cage looks like carbon or graphite.

I ordered the new impeller and pump housing yesterday, basically going to replace everything except the pump cover since I don't have a clue what caused the early failure. 3 to 5 weeks delivery time on the housing as it is not stocked here, special order only. In the meantime I continue to ride the bike and monitor coolant level, so far it's not moved off the full mark.

I'm going to contact KHI and ask about the impeller redesign, doubt I get an answer.

Apparently no one that rides one of these bikes is too concerned about the redesigned waterpump impeller.

http://zx6r.com/zx6r/39663-09-through-12-new-waterpump-impeller-p-n.html

What a mess ! In the continuing saga of the coolant leak, I found a stripped factory installed hose clamp on the rear waterpump hose. I had noticed some suspicious white residue (crystallized coolant) spatter in an area that was hard to inspect and became suspicious of the clamp. It looked tight due to cold flow of the rubber under the clamp but when I put a wrench on it there was no way to tighten it. I pulled it out and several of the threads were pulled through. Possibly installed by the same gorilla that over torqued the OEM oil filter on my 14. I installed a new hose clamp and voila about 95% of the leakage is gone.

I placed the folder paper towel under the weep hole and did two 30 minute rides, result was one of drop coolant each time. I am going to assume that this is a normal leak rate past one of these seals. Basically it would evaporate on the hot engine and except for a slight drop in coolant level over say, 2000 miles, you would never notice it.

Too late to cancel my parts order, I've already payed for the back ordered water pump housing, expensive lesson.

* Last updated by: Kruz on 2/25/2013 @ 6:13 PM *

Oh well... you're getting brandie-new, revised parts. Do a good job on the installation and never worry about that part of your scooter ever again.