rear brake failure

[1warlock]

In the mountains last week running twisties with some very fast guys on sport bikes, dived into turn and pressed rear brake to scrub a little speed and the brake pedal would not move. ??? Ran the rest of the day with just front brakes, back at the base I finally broke the slave cylinder loose, bled the brakes, cleaned around the pedal and slave cylinder and this appeared to make the rear brake work correctly. Went out with the guys to do some more twisties and after about three twisties the pedal froze up again. Continued riding and let the rear brake cool off. Couple hours later I forced the rear brake pedal down and it began working properly. I used it sparingly for the rest of the week without anymore problem. Anyone have a similar problem, if so what did you do to correct it? ???

[ZG]

What year is your Connie 1WL?

[Fred_Harmon_TX]

Did you have any indication that the rear brake was dragging? Check your rotor for discoloration.

It sounds like either your master cylinder is toast or you have a clogged up line, or possibly a linkage problem. Personally, I wouldn't ride the bike until it got resolved. Not having a usable rear brake is one thing, but having your rear wheel lock up on you at speed is another.

There was a recall that added a rock guard to try to prevent rocks from getting in the linkage, but they can still get in there. I don't know if your issue is the linkage, the master cylinder, or the lines, or possible even a problem with the caliper, but I'd want to go through the whole system until I found the cause.

[wayne_jenkins_CT]

I had the same thing happen twice. Both times there were small rocks,1/4 inch in dia. caught in the linkage and I have the rock guard . Do check it out, the last thing you want is a rear brake lock up. Very high Pucker factor when that happens.

[1warlock]

What year is your Connie 1WL?

08 recall done on rock guard.
I checked and cleaned the area around the rock guard and saw no debris and no discoloration when I changed the fluid. Had no problem with rear brake locking up.
I have a service contract with the dealer where I purchase the bike.
Taking bike in for checkup today, I'll post the outcome. Thanks for the pointers.

[jdegraff]

Is it possible you are just overheating the rear brake? I ride Deals Gap a great deal and come across riders who over utilize the rear brake and overheat it. As a rule I don't use the rear brake at all in the twisties.

[JimA]

Is it possible you are just overheating the rear brake? I ride Deals Gap a great deal and come across riders who over utilize the rear brake and overheat it. As a rule I don't use the rear brake at all in the twisties.

+1
I boiled my rear brakes as a noobie in the mountains years ago. Mine went completely soft - nothing there. Fortunately, I had read about it and knew what was happening. Took a nice 15-20 minute rest on the side of the road and the brakes were back. Replaced the fluid as soon as I got home. Live and learn.

[Mad River Marc]

What was the outcome of the tech looking at it?

[JeffF]

First off, I've been away from the forum for some time and tried to log in and was unable so I had to rejoin. I actually used my same information and it allowed me to?

Anyway, I'm researching an issue with my rear brakes and found this thread...

It looks old and it seems to just went cold, but I'm interested to find out if you ever found out the cause of the intermittent brake issue you had 1Warlock. I've been having the same thing for about two months. Just occasionally the rear brake pedal will resist input, then with some extra effort it will break free and work normally. The brake doesn't get tight after it is applied and returns normally. I'm really scratching my head because in my mind if it was a piston seal issue it would be tight in both directions but it has never release abnormally. Also, no leaks and I just replaced the fluid to make sure that it wasn't contaminated. I'd rebuild the cylinder, or even replace it if I thought that would correct the issue, but I don't know that it might not have something to do with the ABS.

Any others with this condition? Anyone identified the cause?

[Umfundisi]

Jeff,

You have not indicated the year of your Connie,  so I will ask the obvious question first.  Have you had the brake recall completed on this bike ?


There is a known issue and a recall that was issued for the rear brake master cylinder linkage which allowed for rocks and pebbles that get kicked up by the rear wheel to get stuck in the linkage and make the rear brake lever stick and jam or cause the brake to drag and overheat.

Kawasaki did issue an initial repair to install a rock guard which in many opinions made the issue worse.  A second attempt, which is the current method, required the replacement the master cylinder rod end and remove the rock guard if it was installed.  See the info below from NHTSA.


Report Date :
July 27, 2012 at 08:10 AM
NHTSA Campaign ID number :  12V343000

Vehicle Make / Model:  KAWASAKI / CONCOURS 14
Model Year(s): 2008-2012
Manufacturer: KAWASAKI MOTORS CORP., U.S.A.
Mfr's Report Date: JUL 18, 2012
NHTSA CAMPAIGN ID Number: 12V343000

Component: SERVICE BRAKES, HYDRAULIC
Potential Number of Units Affected: 13,289

Summary:
Kawasaki is recalling certain model year 2008-2012 Concours 14 (ZG1400 A/B/C/D) motorcycles. Due to a gap between the brake pedal and guard, small
stone or debris can become trapped, creating a brake drag. This can cause the rear brake to overheat, leading to rear brake damage and lock-up or
failure of the rear brakes. The front brakes may also be affected on ZG1400C models.

Consequence:
If the brakes lock up or fail, there is an increased risk of a crash.

Remedy:
Kawasaki will notify owners, and dealers will replace the rear master cylinder rod end and remove the brake guard (if installed), free of charge.
The safety recall is expected to begin on, or about, July 30, 2012. Owners may contact Kawasaki at 1-866-802-9381.

Notes:
Customers may contact the National Highway Traffic Safety Administration's Vehicle Safety hotline at 1-888-327-4236 (TTY: 1-800-424-9153); or go to
http://www.safercar.gov.

[JeffF]

Oops... Sorry about that. I've got a 2008. Nope, I've actually had both recall services done. It's something with the hydraulic circuit, it's not from stones or debris.

[Tundra Tom]

My 2008 had intermitant brake drag from new finally bluing the rotor and cooking the pads. I had it into the dealer a couple times for this issue. I was lucky the tire did not lock, very pissed off, and told the dealer I did not want it back till they found the root cause. Replacing the rear master cylinder finally fixed it, this had nothing to do with rocks or " rider error". Honestly between this and warping front rotors I may be done with Kawasaki. Granted they warrentied everything including the toasted pads. Still the engineering/exacution of the braking system leaves much to be desired for a flagship sport tourer.

[CWalkerD]

Just bought an 08' with ABS. Thought i'd go push some limits to get used to the new turd. Rear brake ABS triggered, then when I let go of the brakes... it wouldn't let go. Came to a stop and it wouldn't release until I turned the bike off and back on again. I've been able to replicate it but not consistently. I called Mama Kawa just to report it. No recall on the ABS unit. All the recalls have been performed on this bike.

Could be a huge issue if you need to brake hard on the highway momentarily and all the sudden your stopping in the middle of the highway without wanting to.

[TimR]

I would replace brake fluid and bleed your rear brakes. Note the color of the fluid coming out. Keep in mind the rear caliper has two bleed valves.


I believe the ABS unit is affected by contamination. First time I replaced brake fluid, I noticed the fluid had turn lightly brown and has black specs in it. After the fluid change I then exercised the ABS unit by finding a gravel road or parking lot and braking hard enough to activate both front and rear. I do this a couple of times a year and bleed the rear every year. I have not had the same experience with the slightly dark and contaminated brake fluid since.


It is my theory he ABS unit fails due to contaminated brake fluid and lack of exercise.  Under normal bike operation the ABS is only activated during very hard or emergency stops. I can think of two times the ABS activated on pavement with my 10 year old C14. Dirt roads are not very common. So far my theory has worked for me. Regular fluid changes and exercise once or twice a year. 


I had all the recalls done. The last recall fixed the rocks on top of the linkage problem by adding round linkage. The square linkage guard over the square linkage didn't work. Rocks still got stuck between the guard and the frame.   

[Freddy]

ABS unit failure on the early bikes is a know issue.  There are several threads on the subject - here's one.

http://forum.cog-online.org/concours-14-zg1400-general-chat-and-tech/update-rear-brake-abs-issue/

[CWalkerD]

You would think if it is due to contaminated fluid that it wouldn't be affected by simply turning the bike off/on again which completely free's the rear wheel when it is stuck prior. Odd issue, I am definitely going to change out the fluids though being a new to me bike and what not. Previous Owner had recently had the stealership change the front fork seals due to a leak. But the front pads / Right rotor are still contaminated, stops like crap right now with the front brakes. Cant even get the ABS to trigger.

I have an "Offer" out on ebay for a used modulator. I'm curious how prolific this problem is. Would suck to change out one pump for another with the same issue. I'm not even fully convinced it's the modulator since power cycling the bike corrects it; seems as though it could be whatever is controlling the modulator.

Is braided brake lines a think on these things? Can I just bypass the ABS alltogether? Surely a thread on this already, new to the forum; so i'll do some digging.

[AmphibSailor]

Last summer in the Alps, I had a similar 'failure.'  Back brake was not there.  It was late and I was in an unfamiliar location.  I reached my destination and parked it...expecting the worst the next morning.  The rotor was very hot.  Turned out to be a bad case of fade.  The fluid was only a week old and was some of the 'good' stuff.  After a night sitting in the cool mountain air, the brakes were back.