Spongy Brakes

[SSGT_B]

I wanted to Crete on singular post for discussion. As many of you have read in a few other of my posts, I have spongy brakes. To date I have:

. rebuilt calipers
. Arashi rotors
. New EBC FA188HH pads

The bike had stainless coated lines on it when I got it. I have gone through about 32 OZ of fluid so far trying to get what feels like air to me out of the system. Ive gravity bled, vaccume bled, pump and hold bled, open then pull lever till stop and close bled. Ive since removed the system as a whole and put it on the bench to do the work, mostly as it hurts to bend over and do this and to not make messes. Ive bench bled the master, then bled the banjos starting at master, then caliper, then nipple. Ive used a sander to vibrate the calipers in hopes of moving trapped air up the system. Ive taped them to my 80 gal compressor and let it run for same reason. Ive left the lever tied back to the bar for days. So here are my thoughts.....

Being as how fluid CANNOT be compressed could I have either:

. Air still in system
. The old lines were junk and need better ones ( not sure of manufacture )
. Fluid internally bypassing in master allowing handle to still be pulled past point of stop?

 

[Bumblebee]

Check your rotors to ensure they are perfectly true...I had one on my Bandit that was ever so slightly out of true and it did just like you are describing. It drove me bonkers until I had it professionally checked and found one rotor slightly out of true...it can happen...

 

[SSGT_B]

Check your rotors to ensure they are perfectly true...I had one on my Bandit that was ever so slightly out of true and it did just like you are describing. It drove me bonkers until I had it professionally checked and found one rotor slightly out of true...it can happen...

Good idea, Ill put a dial indicator on them to check runout. I don't feel however that the immediate issue although may be one of its own. I need a fistful of brake to stop bike. Stoppies or wheel lockup will not happen, not that its the goal. Rear brakes MUST be used to get it to slow down.

 

[Bumblebee]

Good idea, Ill put a dial indicator on them to check runout. I don't feel however that the immediate issue although may be one of its own. I need a fistful of brake to stop bike. Stoppies or wheel lockup will not happen, not that its the goal. Rear brakes MUST be used to get it to slow down.

It sure sounds frustrating....if the rotors are ok, maybe take a little sanding paper to the pads....I dare say but maybe the rotors as well...holding fine emery paper to the rotor and having a helper spin the tire....spray liberally with brake cleaner..it's almost like there is a coating causing the rotor and pads to not grab.

I take it the lever has good pressure and is engaging at the proper distance when the bike is not moving?

 

[SSGT_B]

It sure sounds frustrating....if the rotors are ok, maybe take a little sanding paper to the pads....I dare say but maybe the rotors as well...holding fine emery paper to the rotor and having a helper spin the tire....spray liberally with brake cleaner..it's almost like there is a coating causing the rotor and pads to not grab.

I take it the lever has good pressure and is engaging at the proper distance when the bike is not moving?

The lever is the issue. IT stops, then pulls another inch. Its noticeable in the above video

 

[Bumblebee]

The lever is the issue. IT stops, then pulls another inch. Its noticeable in the above video

Did you rebuild the MC? How are the calipers? Any pistons sticking?

 

[SSGT_B]

Calipers are rebuilt, no sticking pistons. Have not rebuilt MC. Was just on phone with @c10 discussing that the MC is probably bad and has internal bypassing.

 

[Bumblebee]

Calipers are rebuilt, no sticking pistons. Have not rebuilt MC. Was just on phone with @c10 discussing that the MC is probably bad and has internal bypassing.

I agree with Bryan...a rebuild kit is cheap enough...sadly I gave one away which would have worked for you....

 

[Dopey]

Calipers are rebuilt, no sticking pistons. Have not rebuilt MC. Was just on phone with @c10 discussing that the MC is probably bad and has internal bypassing.

My guess would be once you rebuilt the calipers the next weakest link failed. I guess now is a good time ti either rebuild it or look fir that r1 master on Ebay.

 

[fallenarch]

if those are old lines I would not rule out a leak. New lines are not super expensive but you might try new washers at a minimum. Won't you have to remove the lines again to put the system back on the bike (or did I read that wrong). I have heard of the OEM MC crapping out on a couple bikes, before I spent money on that I would go to something better.

 

[SSGT_B]

The lines are braided and I can see no leak. The system I took out in one piece. Did not have to break loose

 

[Sandow]

The lines are braided and I can see no leak. The system I took out in one piece. Did not have to break loose

Where is the wizard @c10 if you need him? (don't you both live close?)
So strange, your issue... I have no idea what to add as a suggestion because everything has already been said...!

 

[Bumblebee]

Where is the wizard @c10 if you need him? (don't you both live close?)
So strange, your issue... I have no idea what to add as a suggestion because everything has already been said...!

Bryan already weighed into this...

 

[Sandow]

Bryan already weighed into this...

I know...i just meant in person. I thought they lived close to each other!... would be awesome material for c10s garage for education purposes!

 

[Bumblebee]

I know...i just meant in person. I thought they lived close to each other!... would be awesome material for c10s garage for education purposes!

Tracking

 

[WuzzaCBXRider]

Sorry to hear this. I’ve had Galfer SS lines and HH pads almost since new (06) and I just changed to Arashi rotors with new pads but that’s all, nothing rebuilt. My lever pull is about a half inch. A (really) hard pull would be maybe a full inch. From what I’ve read over the years I guess I’ve been lucky as they’ve always worked very well. Hope a solution is near. Did you try vibrating the lines starting from down low?

 

[SSGT_B]

Not sure who makes the lines on mine. Wonder if it does make a difference when it comes to those? I have tried vibrate the lines. Used a sander and ran up and down them. Looks as though a new master will be needed. Might have a line on one but if it doesn’t pan out there is eBay.

 

[c10]

Working on getting him a new master off my bike I took off years ago . Gave it to my brother as a spare for his 2015 bird .

 

[Bumblebee]

Not sure who makes the lines on mine. Wonder if it does make a difference when it comes to those? I have tried vibrate the lines. Used a sander and ran up and down them. Looks as though a new master will be needed. Might have a line on one but if it doesn’t pan out there is eBay.

I still say it's the MC...calipers are good, pads and rotors are new, lines are SS, so what else can it be? Has to be the MC...Bryan might even have a stocker you can try out... Edit, I was typing while Bryan was working...

If it's the case you have lots of lever and the pads just aren't biting, try the emery paper on those and the rotors.

If you aren't getting the lever travel you want, it's the MC....take a look at the fluid inside the MC under the cap and see if there are any black particles on the bottom...that would be tiny bits of rubber from the piston seals...

 

[Sandow]

The lines are braided and I can see no leak. The system I took out in one piece. Did not have to break loose

maybe this chart helps....have some pie and think about it!