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My clutch and brake problems continue!

Offgar612

Member
Member
I was told, by a dealership mechanic, I should rebuild the front, rear and clutch Master Cylinders on my 2012 C14. I got the reverse bleed down to a science, but the levers go flat every 50-100 miles. I have bled the brakes several times now and have lost two summers of riding due to this issue, and I have a short riding season up here in Minneapolis. I’m about to drop it off at a church and request an exorcism on it.

1. Any recommendation on brand of rebuild kits and where I can buy all three of them? Murphs only has them for the C10. Out of stock at Dennis Kirk. Partzilla only sells pieces.

2. Brake lines. Might as well replace all my hydraulic cables to rule those out. Spiegler or Galfer? Any suggestions? Very expensive!

3. Brake pads. EBC or Galfer or…?

4. Any recommendations for a Priest that specializes in exorcisms?

Thanks in advance for any feedback!

Signed…Frustrated up in the frozen tundra.

Offgar612
 
Nephew had the same problems with his front brakes.
Rebuilt master. Replaced Calipers. Drained and flushed it a 1000 times.
To solve it, he either replaced the brake lines or the master cylinder.
Don't recall which.

Will see if I can get him to post his fix.

Ride safe, Ted
 
I replaced all my stock lines on my 09 with Gaffer stainless. The brake feel is much, much better for sure. Bleeding the clutch was new for me and took a while to get it right. Brake and clutch performance have remained strong since early May. Well worth the cost and time.
 
I was told, by a dealership mechanic, I should rebuild the front, rear and clutch Master Cylinders on my 2012 C14. I got the reverse bleed down to a science, but the levers go flat every 50-100 miles. I have bled the brakes several times now and have lost two summers of riding due to this issue, and I have a short riding season up here in Minneapolis. I’m about to drop it off at a church and request an exorcism on it.

1. Any recommendation on brand of rebuild kits and where I can buy all three of them? Murphs only has them for the C10. Out of stock at Dennis Kirk. Partzilla only sells pieces.

2. Brake lines. Might as well replace all my hydraulic cables to rule those out. Spiegler or Galfer? Any suggestions? Very expensive!

3. Brake pads. EBC or Galfer or…?

4. Any recommendations for a Priest that specializes in exorcisms?

Thanks in advance for any feedback!

Signed…Frustrated up in the frozen tundra.

Offgar612
I am no motorcycle tech but I have encountered similar issues. IMO, I believe what is causing your issue is one of two things.

#1) Fluid is getting past the seals inside the master cylinder. When this happens, there is no build up of hydraulic pressure in the hose, causing the levers to go straight to the handlebar. If you have rebuilt the master cylinder including the internal seals (which it sounds like you have) then there is likely an issue with the internal casting of the master cylinder causing the seal to not seal properly. In this case the master cylinder would need to be replaced.

#2) The rubber hydraulic lines are worn out. If the master cylinders are doing their jobs then the hydraulic lines would be the next culprit. If the rubber lines are so soft from use that they no longer maintain their rigidity, they will expand every time you pull in the lever or push the brake pedal. This expansion will not allow full hydraulic pressure in the line To activate the caliper. I have never seen this issue cause what you are experiencing though. I have seen this happen but never to the extreme you are experiencing. Not even close. This issue typically just causes the brakes to feel spongy, but they still work.

I believe somewhere you have hydraulic fluid that is passing a seal SOMEWHERE causing you to have very limited or no hydraulic pressure.

How many miles on your C14? Have you rebuilt the master cylinders or just bled them? Have you ever rebuilt the calipers? Those have seals in them too.
 
I am no motorcycle tech but I have encountered similar issues. IMO, I believe what is causing your issue is one of two things.

#1) Fluid is getting past the seals inside the master cylinder. When this happens, there is no build up of hydraulic pressure in the hose, causing the levers to go straight to the handlebar. If you have rebuilt the master cylinder including the internal seals (which it sounds like you have) then there is likely an issue with the internal casting of the master cylinder causing the seal to not seal properly. In this case the master cylinder would need to be replaced.

#2) The rubber hydraulic lines are worn out. If the master cylinders are doing their jobs then the hydraulic lines would be the next culprit. If the rubber lines are so soft from use that they no longer maintain their rigidity, they will expand every time you pull in the lever or push the brake pedal. This expansion will not allow full hydraulic pressure in the line To activate the caliper. I have never seen this issue cause what you are experiencing though. I have seen this happen but never to the extreme you are experiencing. Not even close. This issue typically just causes the brakes to feel spongy, but they still work.

I believe somewhere you have hydraulic fluid that is passing a seal SOMEWHERE causing you to have very limited or no hydraulic pressure.

How many miles on your C14? Have you rebuilt the master cylinders or just bled them? Have you ever rebuilt the calipers? Those have seals in them too.
I just bled them several times. After the bleed, everything is tight and fine. Then it slowly gets sprongy and then finally nothing at all. No brakes, no clutch.
I have 33,000 miles on the C14.
 
I just bled them several times. After the bleed, everything is tight and fine. Then it slowly gets sprongy and then finally nothing at all. No brakes, no clutch.
I have 33,000 miles on the C14.
Since this is happening in both systems - clutch and brake - What has been used?

Also is the machine still under warranty, only 33K miles?

Wayne
 
I just bled them several times. After the bleed, everything is tight and fine. Then it slowly gets sprongy and then finally nothing at all. No brakes, no clutch.
I have 33,000 miles on the C14.
Then in my opinion you need to rebuild the master cylinders. Start with the brake master cylinder. I would almost guarantee you that will solve your problem. The kit you need is Kawasaki part # 43020-0010. It’s $62 on https://www.motosport.com/oem-parts/part-number/43020-0010?mmy=kawasaki;concours 14 (abs) ;2012&group=front-master-cylinder&qty=1

While you are in there it’s not a bad idea to replace the diaphragm for the reservoir and any additional o-rings. I think there is only 1.

The job shouldn’t be difficult. The hardest part is bleeding the brakes which it sounds like you are already proficient at.

There will be similar parts for the clutch and rear brake master cylinders. I would start there before replacing the lines.

If you need help ordering the parts shoot me a PM and I’ll help guide you.
 
Brake and clutch have one common element - fluid. If a fluid was used that attacked rubber seals, then everything rubber the fluid has contacted may be suspect.
 
I went through a few bottles of Bel Ray DOT 4 fluid when changing the lines. It is so clear now that I have a tough time seeing the levels. Great feel though.
 
I’ve been using Motul DOT 4. I believe I used Castrol DOT 4 before that.

I just ordered the front, rear mc rebuild kit and the clutch mc rebuild kit from All Balls Racing. I hope these will solve the problems. If not, I’ll rebuild and clean the calipers.

Oh…another thing…I saw a video where the presenter said that if the black rubber diaphragm in the reservoir is pulled/extended out when you first open it, you must replace your brake pads.
Any truth to this? My front and rear reservoir diaphragms are extended every time I open them up.

Thanks for all the replies so far!!

Offgar612
2012 C14
 
I’ve been using Motul DOT 4. I believe I used Castrol DOT 4 before that.

I just ordered the front, rear mc rebuild kit and the clutch mc rebuild kit from All Balls Racing. I hope these will solve the problems. If not, I’ll rebuild and clean the calipers.

Oh…another thing…I saw a video where the presenter said that if the black rubber diaphragm in the reservoir is pulled/extended out when you first open it, you must replace your brake pads.
Any truth to this? My front and rear reservoir diaphragms are extended every time I open them up.

Thanks for all the replies so far!!

Offgar612
2012 C14
I’ve never heard of anything like that. I don’t k or what the diaphram would have to do with the brake pad wear…. Sounds dumb to me.
 
I’ve been using Motul DOT 4. I believe I used Castrol DOT 4 before that.

I just ordered the front, rear mc rebuild kit and the clutch mc rebuild kit from All Balls Racing. I hope these will solve the problems. If not, I’ll rebuild and clean the calipers.

Oh…another thing…I saw a video where the presenter said that if the black rubber diaphragm in the reservoir is pulled/extended out when you first open it, you must replace your brake pads.
Any truth to this? My front and rear reservoir diaphragms are extended every time I open them up.

Thanks for all the replies so far!!

Offgar612
2012 C14
The extended diaphragms indicate fluid extraction with their purpose of extending to reduce the movement of fluid and keep air away from the fluid.

I look forward to hearing what happens after the rebuild(s), however I am still interested in this such a peculiar issue that you are having on both clutch and brakes on what seems like not a terribly old machine. No leaks huh? No fluid coming out but the diaphragms are drawing down every time after bleeding, refilling, covering and just a few hours riding and you have to bleed the brakes and clutch again?

Are you filling the fluid to the full lines with the bars turned to have a level reservoir? Are you also bleeding the top bleeders at the master cylinders as part of the bleed process?

Do you push the pads back when bleeding? If so after filling fluid them covering and pumping the brakes up that would definitely draw level down for brakes….

If I understand correctly both reservoirs the diaphragms are sucked down after just a few hours riding?

Wayne, Carol & Blue
 
Here is the video where the instructor talks about the diaphragm correlation with brake pad wear.

You can start it at 5 minute 30 seconds.

 
When your pad wear the pistons extend further. More volume in the wheel cylinders = lower fluid level in the master. The diaphragm extends due to the vent being on top of the diaphragm. New pads you push in the pistons to get them on and the fluid is pushed back into the master the diaphragm needs to be pushed back up to the top of the cover.
 
Sorry for the delay. I was finally able to contact my nephew.
(Working out of town)
He had same issue with his front brakes.
Flushed and bleed them REPEATEDLY, rebuild master cylinder x2, replaced both front calipers.
Would think it fixed, would have good lever, then it would go to the grip the next day.

Came down to replacing master cylinder or replacing hoses.
Replacing the master Cylinder made the most sense, but he opted to replace the hoses, and the problem was solved.

I have no idea how the hoses could cause the issue.
They did not leak fluid, looked fine.
But, it worked.

Ride safe, Ted
 
Sorry for the delay. I was finally able to contact my nephew.
(Working out of town)
He had same issue with his front brakes.
Flushed and bleed them REPEATEDLY, rebuild master cylinder x2, replaced both front calipers.
Would think it fixed, would have good lever, then it would go to the grip the next day.

Came down to replacing master cylinder or replacing hoses.
Replacing the master Cylinder made the most sense, but he opted to replace the hoses, and the problem was solved.

I have no idea how the hoses could cause the issue.
They did not leak fluid, looked fine.
But, it worked.

Ride safe, Ted
Thanks Ted! I’m going to work on the master cylinders today. Hope that does it.

Offgar612
 
Earlier, brake fluid was mentioned, and I agree. It's possible that a prior owner or service tech put in some incorrect fluid that wasn't compatible with the seals. Of course, if you're the original owner, have done every service yourself, and have used the correct fluid, that theory goes out the window. But if at some point incorrect fluid was used, and it weakened the seals, even if it was swapped out later for the proper fluid, the pressure over time could have turned the weakened seal into a failed one.

My biggest reason for suspecting fluid is because the front brake, rear brake, and clutch are completely separate hydraulic systems. It's telling and very uncommon that all three would fail near the same time on a 10-year old motorcycle. If a PO was doing "thorough" maintenance and flushed all three systems with the same brake fluid they had sitting on their shelf, which was incompatible, it would make sense that all three systems with separate fluid reservoirs would fail at the same time.

I suspect that a complete rebuild will fix it. Looking forward to the results, and good luck with the rebuild process.
 
Earlier, brake fluid was mentioned, and I agree. It's possible that a prior owner or service tech put in some incorrect fluid that wasn't compatible with the seals. Of course, if you're the original owner, have done every service yourself, and have used the correct fluid, that theory goes out the window. But if at some point incorrect fluid was used, and it weakened the seals, even if it was swapped out later for the proper fluid, the pressure over time could have turned the weakened seal into a failed one.

My biggest reason for suspecting fluid is because the front brake, rear brake, and clutch are completely separate hydraulic systems. It's telling and very uncommon that all three would fail near the same time on a 10-year old motorcycle. If a PO was doing "thorough" maintenance and flushed all three systems with the same brake fluid they had sitting on their shelf, which was incompatible, it would make sense that all three systems with separate fluid reservoirs would fail at the same time.

I suspect that a complete rebuild will fix it. Looking forward to the results, and good luck with the rebuild process.
Very good point. Use of incompatible fluid could act like a phantom problem due to all the degraded seals. I have a friend with a Road King that continues to have degrading front lever feel after fluid change and bleeding. I suggested a rebuild kit for both master cylinder and caliper with a stainless line. Never thought of this being caused by the prior owner using the wrong fluid.
 
I just talked to a guy that bought an old Harley that someone filled with the wrong fluid. He said he replaced the master cylinder.
 
I think it's better to use bungee cords rather than zip ties. You can measure lever distance at start and see how much it creeps in overnight.
 
From my experience with this bike, I would say changing brake and clutch fluid is wise to do every two years.
 
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