Hi.
I have a 2013 ZX14R a few weeks out of warranty. Bought it new. The bike has travelled ~7500km and is always garaged. It has a full service history at the same dealer I purchased from & was in mint, unmarked condition. Two days ago I attended a Kawasaki track day at Qld Raceway. The afternoon prior I dropped into my local Kawasaki dealer to check the front brakes in preparation, as I noticed the master cylinder fluid was below the halfway mark. They advised all "good for at least another 6000km & safe for trackday", topped up the master cylinder fluid and sent me on my way. In my first session on track, early in the cold morning, after ~10 laps without issue (no sponginess or notable fading), my front brakes failed completely heading into turn one at 200km/hr+. No lever pressure at all despite me frantically pumping it hoping for some retardation. Lever just flopped back to the bar. Consequently I sailed though the corner & into the gravel trap where the bike dug in & I went over the bars. On picking up the bike I checked fluid level (still good) and lever pressure (still zero, but returned after ~5mins). Luckily the limited retardation available using the rear brake + engine braking had slowed me enough to limit the damage to both myself & the bike, though I'm sure panel damage alone will be in excess of $2K. My main concern however is the catastrophic brake failure I experienced. If this had happened down the back straight at 250+ before the tight right-hander I probably wouldn't be able to type this now.
Please understand I'm no racer or regular track day attendee. I'm a 75kg, 50 year old rider with 33 years constant bike riding ownership & experience. Brakes aren't warped & now feel normal. I left the bike with my dealer for assessment. They can find no fault except indicating that the brake fluid likely boiled (fluid discolouration was mentioned). I've told them that I no longer feel safe riding this bike on road or track unless a fault is found. In my industry we don't let these things slide. IMO this is NOT a normal failure. If it was there'd be dead track day riders everywhere. There were several other ZX14Rs present on the day, many with riders much heavier than I & who rode & braked much harder who had no issue.
Anyone else heard of this issue? Thoughts??

* Last updated by: TimMc on 9/3/2015 @ 1:17 AM *

You can easily measure the water content in the brake fluid. If it turns out to be 3% or over then you know why it boiled.
If it is 1% or less, then the mystery remains..

What mods do you have regarding brakes? Levers, lines, pads? Catastrophic failure is not normal, it sounds like your fluid got so hot that the hose flexed to the point that it failed due to heat

"Coming back then to the point of this article on vapour lock (or vapour lock). This is the conversion of water in the brake fluid to steam when the brakes are heated significantly which causes compressibility in the brake system. This vapour lock leads to increased pedal travel and can result in a significant loss of brake effect".

You say 10 laps...could this be the problem?Water in the fluid will vaporize at 100 degrees.Perhaps you heated the brakes to that point in your 10 laps?

* Last updated by: Grn14 on 8/20/2015 @ 9:01 AM *

It's got to be vapour lock IMO. Surely any sort of mechanical failure like blown/distended hoses or seals would not right itself after 5 min cool down.
Are you certain the brakes are free from drag? Even a light drag which could go unnoticed on the road could prove problematic in a track day environment where brake use is much harder and longer with comparatively little cool down time. JMO

It's not vapor lock - its air coming out of solution and forming bubbles when the fluid get hot. How did the air get there?? Break fluid is hydroscopic and attracts/absorbs H2O, especially as it ages and gets old. The reservoir has a breather hole. Most probable cause of your failure was you cooked the brakes, boiled the fluid which created air bubbles and that nice little hydraulic pump of a master cylinder compressed the gas and not your pads. Switch to the Motul 600 brake fluid and change the fluid before each track day (or at least once a year) and you will be good.

[quote]It's not vapor lock - its air coming out of solution and forming bubbles when the fluid get hot. How did the air get there?? Break fluid is hydroscopic and attracts/absorbs H2O, especially as it ages and gets old. The reservoir has a breather hole. Most probable cause of your failure was you cooked the brakes, boiled the fluid which created air bubbles and that nice little hydraulic pump of a master cylinder compressed the gas and not your pads. Switch to the Motul 600 brake fluid and change the fluid before each track day (or at least once a year) and you will be good.
/quote]

The 'air' in the brake line is not air but water vapour from heating the water absorbed in the fluid. Not the same thing. Air will not be held in solution in the fluid. When the fluid cools the vapour is re absorbed back into the fluid as water, hence the return of brake pressure. Much the same as fuel vaporising in a fuel line and causing fuel pressure loss. It's vapour lock.

OK substitute O2 for Air, maybe your basic physics classes in the UK are different from the US but water vapor is H2O and the gas coming out of solution is O2

Peg,

I say football you say football, are we talking about the same game or a different one?

ABS bike? Maybe the ABS freaked out, though I tend to agree with the boiling fluid theory. Considering what you were doing, that is the most likely explanation.

* Last updated by: lemosley01 on 8/20/2015 @ 7:02 PM *

"The reservoir has a breather hole"....hmmm...interesting.Didn't know that...thanks.This is so if you overfill the res and the expanded fluid (from heat)can escape before the brakes lock up?

"H2O"...isn't that...two hydrogen atoms and one oxygen atom?At the right temp,doesn't this create water vapor?(a gas).Which IS compressible.

Hi John.
I've asked them to save a sample of fluid from the calipers for testing so I might follow through here.

Hi Seno.
Brakes are completely standard. Hard to imagine that a two year old hose could flex that much under heat, but could be the case.

Hi Grn14.
Yes temp was likely the issue and I've certainly boiled fluid in my car brakes on track, but in those cases the pedal became mushy (due to the compressibility of vapour compared to fluid). I've never experience a total failure like this and I haven't heard of anyone else experiencing it.

Hi pegscraper.
Yes, likely a vapour issue. But why so catastrophic without warning? After I came back to the pits we leaned the bike over on the side stand with the front wheel in the air, spun the wheel and checked for trueness of the discs. There was no drag (then) and discs are straight. Dealer mechanics are suggesting I may have been holding the front brake on while I rode, but that's not likely. I'm kinda incapable of using the throttle & brake at the same time...

Thanks crude.
If I ever trust this bike enough to take it back to the track I'll certainly be flushing the fluid with some 600 or better beforehand. I put this to the dealer (workshop lead mechanic) the day beforehand but he assured me what was in there was fine...

* Last updated by: TimMc on 8/20/2015 @ 11:26 PM *

Yeah lemosley, I asked several Kawasaki mechanics if the ABS could be the issue. They suggested that the ABS was built such that it would fail-safe, i.e., revert to a normal non-ABS braking system. I'm still dubious.

I rang "Kawasaki Australia" yesterday to try and get some; feedback, information, comment, anything. I was fended off by the guy who answered the phone who refused to let me talk to the technical department or anyone in management. He told me to just ask for information via the website and they would get back to me. This I did, but I'm yet to hear back.

* Last updated by: TimMc on 9/3/2015 @ 1:20 AM *

"revert to a normal non-ABS braking system. I'm still dubious"...yes,it will.

the only time that has happened me, is after a massive tank slapper, which caused the caliper pistons to be forced back, but usually a pump or two of the lever gets you back, but late braking does not leave you with much time, and the suprise you get /panic also leaves you in the gravel or in a field before you can say...wtf!!"ohhhh shittt

over heating brakes usually leads to bad brake fade first, you were riding only you know just how much braking you were doing and if you were getting lots of fade, but as you said, no lever at all...very strange if the pistons had not receeded,

* Last updated by: motero on 8/21/2015 @ 2:57 AM *

"revert to a normal non-ABS braking system. I'm still dubious"...yes,it will.

"the only time that has happened me, is after a massive tank slapper, which caused the caliper pistons to be forced back, but usually a pump or two of the lever gets you back, but late braking does not leave you with much time, and the suprise you get /panic also leaves you in the gravel or in a field before you can say...wtf!!"ohhhh shittt
over heating brakes usually leads to bad brake fade first, you were riding only you know just how much braking you were doing and if you were getting lots of fade, but as you said, no lever at all...very strange if the pistons had not receeded,"
I was getting a few mild head shakes sometimes coming onto the main straight, particularly when changing up to 3rd at redline, but nothing too bad. Certainly not a full on stop to stop tank slapper. However from failure to recovery (post crash) I must have operated the lever at least a dozen times to no effect. I certainly was braking hard, but yes the feel was hard & the retardation felt consistent right up until failure.

Just got a reply from Kawasaki.
"Dear Mr TimMc,

Thank you for contacting Kawasaki Motors with your enquiry and we were very sorry to hear of your accident while on our KTGA track ride day.

Kawasaki Motors has been working closely with Team Moto **** who has been investigating your report of “front brake failure”. **** ***** the service manager at Team Moto **** has advised Kawasaki Motors Pty LTD, that they have now concluded their investigation on your ZX1400FDF (VIN: JKBZXNF19DA003937) brake system. During this investigation NO manufacturing defects or any other abnormal operating conditions were evident with the brake system installed on your motorcycle, and they were found to be operating normally without fault. Your ABS system has also been checked using the latest Kawasaki diagnostic computer software, which also did not reveal any faults with your motorcycles ABS system.

**** has also advised us, that the most likely cause of your front brake concerns was actually caused by abnormally high temperatures in your front brake system, this may have caused the moisture contained in your brake fluid (which is several years old) to “boil”. This would have allowed vapour to develop in your front brake lines causing the “loss” of front brake.

**** has replaced the brake fluid in your front brake system and he has done this under Team Moto “goodwill” with no charge to you, your motorcycle has been thoroughly road tested and is now ready for collection.

Kawasaki Motors would therefore advise remaining in contact with **** at Team Moto ****, as he is best suited to assist you with all your Kawasaki needs. Please also be advised that we have copied **** in on this email, so he is fully aware of the concerns you have raised with Kawasaki Motors.

Kind Regards
**** ******
TSD Assistant - Dealer Tech Support
Kawasaki Motors Pty Ltd."

Look after all this I'll probably flush with a high temp fluid before I ever go back on track on any bike, but I'm still not sure that they've found the real issue here or that a well maintained, low km bike should fail in such a dramatic way.

* Last updated by: TimMc on 8/21/2015 @ 5:19 AM *

Hmmm...well...at least they DID something.Is there such a thing as a 'high temp' fluid?Might just want to consider staying with fresh DOT4...total system bleed and refill.Somehow your fluid apparently got MORE 'water' in there than 'normal'.Glad you got it sorted...have fun....sorry about your bike...

DOT 4 brake fluid for example has a boiling point of around 230 degrees centigrade, but once the fluid absorbs enough moisture to the point where it is then made up of just a few percent water, the boiling point can drop as much as 80 degrees C.

DOt 5.1 has a higher boiling point, but is more hydroscopic

i would definately change brake fluid minimum of once a year racing/track days.

Excellent comment Mo.

[quote]OK substitute O2 for Air, maybe your basic physics classes in the UK are different from the US but water vapor is H2O and the gas coming out of solution is O2/quote]

I guess physics lessons must be different then. Water vapour is the gaseous phase of water. It's the vapour that cause the brake problem not O2. To get O2 from water requires electrolysis to separate the H and O molecules.

[quote]"The reservoir has a breather hole"....hmmm...interesting.Didn't know that...thanks.This is so if you overfill the res and the expanded fluid (from heat)can escape before the brakes lock up?/quote]

Grn,

As I understand it the breather hole in the cap is equalise the pressure inside and outside the reservoir. If there was no breather a vacuum would form as the fluid in the reservoir gets lower due to pad wear.

Can someone SHOW me this breather hole?Or exactly WHERE it is on the rez?I've never seen this...I'd like to.

The reason the rubber diaphram 'drops' when fluid levels start getting lower is BECAUSE of the vacuum in there.Otherwise,it'd stay up in the cap.And you'd have an air gap on top of the fluid...meaning...water entering from the atmosphere...(in the form of vapor).If you fill the res say halfway...and cap it with the diaphram pushed up into the cap...any fluid loss will pull the diaphram down.Doesn't sound to me like there's a 'vent' hole in there anywhere?I could be wrong.

Anyone else have a 'vent hole' in their Reservoirs?It's supposed to be a closed system...

I think in the manual it mentions inspecting the cap and diaphram for any cracking or deterioration.Apparently it's not supposed to have any way for any outside air to enter...I'm guessing.

* Last updated by: Grn14 on 8/21/2015 @ 10:26 AM *

"Look after all this I'll probably flush with a high temp fluid before I ever go back on track on any bike, but I'm still not sure that they've found the real issue here or that a well maintained, low km bike should fail in such a dramatic way"...you're probably just fine now.I wouldn't change any fluid.(since they did that).

* Last updated by: Grn14 on 8/21/2015 @ 11:11 AM *

Okay...I bit.About the breather hole thing...

*This thread* makes me want to change my brake fluid ASAP.

It gets regular service, sure, but I think I'll just "tighten up" on my maintenance schedule a bit.

I'm sure glad you're OK. There was a brief description of you "over the bars", and then picking up the cycle. We all do that huh? "Wow, I just landed on my ass. Wait! The cycle is still fallen, I'd better get right over there 'n pick it up. Ummm, whats that grinding sound from my shoulder?"

I'm just glad you're OK, Tim.

Find something you trust, and ride that.