Kawasaki Concours Forum

The C-14, aka Kawasaki Concours-14, the new one :) => The Bike - C14/GTR 1400 => Topic started by: chap on March 28, 2018, 07:00:24 PM

Title: Front Brake feels soft
Post by: chap on March 28, 2018, 07:00:24 PM
Getting my 2010 ABS out of storage and the front brake lever  seems to travel more  than i remember. Checked  it out and the ebc pads have about 3mm left. Bled the brake both sides and still feels soft. So i replaced the  Brake  fluid and still the same. Anyone have any ideas
Title: Re: Front Brake feels soft
Post by: Poseidon on March 28, 2018, 07:53:38 PM
There have been a lot of post here recently about the 2010, so I am posting with the assumption that you have linked brakes. Did you bleed the rear brakes too? Linked brakes can allow air into the system front to rear, so bleeding the only the front brakes won't get all of the air out of the system.
Title: Re: Front Brake feels soft
Post by: chap on March 28, 2018, 09:03:59 PM
Yes i bled the rear as well. I have always had an issue with the rear underperforming. So bled the rear both points as well. I did not change the rear fluid completely. Just checked for air in the system. Yes it is an abs bike sorry I didn't  put that before.
Title: Re: Front Brake feels soft
Post by: 2talltim on March 29, 2018, 09:10:11 AM
Pull the brake lever back tight and hold it over night that way with a zip tie. Check again the next morning.

Your welcome...hopefully
Title: Re: Front Brake feels soft
Post by: just gone on March 29, 2018, 10:53:34 AM
Bled the brake both sides and still feels soft. So i replaced the  Brake  fluid and still the same. Anyone have any ideas

The first time I bled the front brakes (also a '10 ABS), I got carried away with the sucking (EZgirls) and I let the top reservoir get  too low. I added more fluid hoping I didn't let any air in and continued bleeding at the bottom on both sides. However, the lever remained spongy feeling until I closed the bottom bleeder and then bled the air out at the top bleeder at the reservoir. It then firmed right up (Girls!) and I continued the fluid change.

I'm sorry if you've done all that already and still have the problem, but it's hard to tell what has actually occurred when someone just says they "replaced the brake fluid"

Linked brakes can allow air into the system front to rear, so bleeding the only the front brakes won't get all of the air out of the system.

I'm not sure that is 100% accurate, they are linked, but I don't think there is any direct fluid contact between front and rear systems. That is air cannot move from the front into the rear or vice versa unless there is seal failure inside the ABS pump itself, I believe the only connection is electronic via pump. Yes ? No?

 This (attachment) from the shop manual diagrams: shows the only inter connection is the pump motor. (I think)


Title: Re: Front Brake feels soft
Post by: B.D.F. on March 29, 2018, 03:13:37 PM
I find the C-14 to be a tough bike to bleed the hydraulics on. So two things have worked well for me: 1) when I am done bleeding the brakes, I bleed them at least two more times (seriously) 'cause I am not really done and 2) a power bleed is <almost> a requirement, especially if any air is in the system. It sounds like some air has entered your front brake circuit and so more bleeding and more intense bleeding is needed to clear it all out.

What I have found is that it is easy to bleed the hydraulics on a C-14 to about 96% done but that last 4%, so they feel rock- hard and are not soft or 'squishy' at all is tough.

Brian

Getting my 2010 ABS out of storage and the front brake lever  seems to travel more  than i remember. Checked  it out and the ebc pads have about 3mm left. Bled the brake both sides and still feels soft. So i replaced the  Brake  fluid and still the same. Anyone have any ideas
Title: Re: Front Brake feels soft
Post by: maxtog on March 29, 2018, 03:54:44 PM
I'm not sure that is 100% accurate, they are linked, but I don't think there is any direct fluid contact between front and rear systems. That is air cannot move from the front into the rear or vice versa unless there is seal failure inside the ABS pump itself, I believe the only connection is electronic via pump. Yes ? No?

I believe you are correct.  They are two (front/back) are totally different circuits.  The fluids never touch/mix.
Title: Re: Front Brake feels soft
Post by: Poseidon on March 29, 2018, 07:14:20 PM
Interesting!  I have had bikes with linked brakes before, but they didn’t have ABS. Most recent one was on my Can Am XMR 1000 (ATV). That one was a PITA to bleed because the fluid did cross from front to back. Never even crossed my mind that ABS would change that.

That being said, what part of the system is it that makes it so hard to bleed then? Doesn’t the front brake and clutch MCs have top bleeders also?
Title: Re: Front Brake feels soft
Post by: B.D.F. on March 29, 2018, 07:24:25 PM
Not sure what makes it so tough to bleed but the hole from the reservoirs to the M/C is very small, and often a dry M/C simply will not or cannot draw any fluid into it from the reservoir above. If fluid does transfer, again the volume is so low that there is not enough fluid flow to carry out the small bubbles trapped w/in the system. After all, at some point air must be drawn down to bleed brakes and if the brake fluid will just not move fast enough, it will not carry the small bubbles down with it.

Power bleeding in nothing magic, it just applies more pressure to the system than can be managed with at least a partially empty M/C. So the fluid flow is increased and the last bit of air (foam really) is chased out of the system. Or at least that is my theory- it may be worth what it cost. :-)

Brian

Interesting!  I have had bikes with linked brakes before, but they didn’t have ABS. Most recent one was on my Can Am XMR 1000 (ATV). That one was a PITA to bleed because the fluid did cross from front to back. Never even crossed my mind that ABS would change that.

That being said, what part of the system is it that makes it so hard to bleed then? Doesn’t the front brake and clutch MCs have top bleeders also?
Title: Re: Front Brake feels soft
Post by: Poseidon on March 29, 2018, 07:33:49 PM
Not sure what makes it so tough to bleed but the hole from the reservoirs to the M/C is very small, and often a dry M/C simply will not or cannot draw any fluid into it from the reservoir above. If fluid does transfer, again the volume is so low that there is not enough fluid flow to carry out the small bubbles trapped w/in the system. After all, at some point air must be drawn down to bleed brakes and if the brake fluid will just not move fast enough, it will not carry the small bubbles down with it.

Power bleeding in nothing magic, it just applies more pressure to the system than can be managed with at least a partially empty M/C. So the fluid flow is increased and the last bit of air (foam really) is chased out of the system. Or at least that is my theory- it may be worth what it cost. :-)

Brian

I’ve always used a mighty vac bleeder. Works well in most cases. Another trick that works in that situation is to rapidly tap the lever with the revisor cover off. You will see a stream of very small bubbles coming up thru the fluid.  It accomplishes the same as zip tying the lever down over night, only it doesn’t take all night!
Title: Re: Front Brake feels soft
Post by: kzz1king on March 29, 2018, 09:46:35 PM
Brian had a nice write up on using a power bleeder a few months back. Thought I had it bookmarked but cant find it.

Wayne
Title: Re: Front Brake feels soft
Post by: Eupher on March 30, 2018, 03:59:51 AM
Yep, the Mighty Vac seems to have a spotty record with the C14. Some guys use it well and others don't - and the quality of the current crop of Mighty Vac vacuum tools (wanted to say "sucker" but also wanted to avoid the "Easy Boys!" warning  :) ) is even spottier.

I went with the powered vacuum setup when I did both front and rear brakes and the clutch and it worked pretty painlessly.

And I didn't even get brake fluid on the Tupperware (though I covered it per Fred Harmon's suggestion).
Title: Re: Front Brake feels soft
Post by: chap on March 30, 2018, 05:06:56 PM
Thank you everyone with your helpful  replies. I bled the top bleed at the mc. Bubbles came out and now  a nice firm lever. Now just need  the snow  to melt so I can  get on the  street.
Title: Re: Front Brake feels soft
Post by: Poseidon on March 30, 2018, 05:20:19 PM
Thank you everyone with your helpful  replies. I bled the top bleed at the mc. Bubbles came out and now  a nice firm lever. Now just need  the snow  to melt so I can  get on the  street.

Glad it was something simple and you got it taken care of. Unfortunately, I have no suggestions on getting rid of the snow, other than move somewhere warmer. lol
I liked the snow as a kid, but now...