Front Brake Problem

Berlin Germany said:
@Hayabusa Wannabe
yes, I'm still alive and I'm not that nun ;-)
i only use words
and
I just have serious private problems that aren't suitable for the public - so don´t ask

my solution:
completely dismantle the brake calliper/calipers
carefully remove the seals
deep clean the grooves in the callipers until they shine and no longer show any dirt
clean the old seals
if they have a kind of orange peel skin effect (especially on the outside of the ring) - it doesn't matter at all - they can easily be used again

that's how I've been doing it with complete success since I started cleaning the callipers

put everything back together

BUT only and exclusively use ATE brake paste (or 100% equivalent) or DOT4/5.1 - NOTHING else

oh yeah, I almost forgot - the pistons should also be "polished" - at their outside - until they show absolutely no dirt

and for the gen1 callipers:
repeat the deep cleaning every 30-35,000 km

and it fits with the first braking (after the cleaning) - the brake suddenly works very well again

see pics of my homepage here
Click to expand...
Guten tag,

Good to see you posting again and we've missed you.
 
Hayabusa Wannabe said:
Over the weekend I also texted the phone number on @Berlin Germany’s web site. I have not received any response. :(
Click to expand...
try, next time Whatts App:D

same mobile phone number
prerequisite you have an internet connection via WA
i´m at home so i have that 24h / day / 7 days a week
that should work from all over our blue ball
even foning with picture/movie worked last year with indonesia
 
Didn't want to jack up "What did you do to your busa" thread with this, but I think my calipers are leaking after the rebuild :banghead:
To catchup: did a caliper rebuild (cleaned and new seals), gravity bled/primed the hoses, pump bled like normal, and strapped lever overnight with MC lid off. I put a board under the front wheel so I could see if anything leaked overnight.
Next morning: R caliper had a drop forming, but L caliper dripped several times. Re-bled to make sure no air, made sure I could stop in the neighborhood a few times, and then went to work.

Bottom of calipers were wet to touch when arriving at work. I'm not sure where it is directly coming from, but it does not look like the bleed bolts. I made painstakingly sure that the little inner gaskets were lined up before tightening the calipers together. What are the torque specs for the 4 caliper bolts?
 
Just an fyi
Leave the mc cover on, there is no need for it to be off, and the fluid in the resivor will absorb moisture from the air.
Let me look for the torque specs, as they can be a pain to find.
 
Did you put brake fluid on the new piston seals? To lubricate them so they don't stick or roll when the pistons move.
A dry assembly will damage the seals and cause a leak.
 
sixpack577 said:
Did you put brake fluid on the new piston seals? To lubricate them so they don't stick or roll when the pistons move.
A dry assembly will damage the seals and cause a leak.
Click to expand...
I used the red rubber grease that comes with the kit. Rubbed all seals before putting them in, and put a thin layer on the pistons. Pushed in the pistons till I could see the top little seal. All pistons were pushed out after bleeding (so they are moving), but one side is out more than the other.

Also, looks like 21nm, which is laughable considering how difficult they were to take out.
 
BlueBacon said:
I used the red rubber grease that comes with the kit. Rubbed all seals before putting them in, and put a thin layer on the pistons. Pushed in the pistons till I could see the top little seal. All pistons were pushed out after bleeding (so they are moving), but one side is out more than the other.

Also, looks like 21nm, which is laughable considering how difficult they were to take out.
Click to expand...

Yeah, strange to see the pistons not move the same amount.
I wish that I had an answer, but you'll have to confirm a leak, or the leak's source.
Is the lever spongey or losing pressure?
Did you get a small amount of air out after untieing the lever and bleeding again, or did you have to bleed it a few times again?
Are the brake lines stock?
 
sixpack577 said:
Yeah, strange to see the pistons not move the same amount.
I wish that I had an answer, but you'll have to confirm a leak, or the leak's source.
Is the lever spongey or losing pressure?
Did you get a small amount of air out after untieing the lever and bleeding again, or did you have to bleed it a few times again?
Are the brake lines stock?
Click to expand...
The pistons are moving equally on their respective side at least! All 3 on one side are the same distance...other 3 on the same caliper are out an equal distance, but not as far as the other side. Pistons were all over the place before this.

No air after releasing lever and nothing for the few bleeds afterwards either.
Stainless lines-stock MC-aftermarket lever-no noticeable loss of pressure or response in lever all morning.
Sight glass is full of fluid when upright with bars straight, but about half full when bike is on kickstand with bars in full left lock.
Since I'm not certain if it is leaking or just fluid coming out of the cracks during bleed spillage, I have not tested an emergency stop yet...just slow 30-0 MPH. I can definitely tell the stopping power has been greatly improved even with how little I've pulled the lever, but I want to make sure the system is 100% good to go before I do any potential tests.
 
BlueBacon said:
The pistons are moving equally on their respective side at least! All 3 on one side are the same distance...other 3 on the same caliper are out an equal distance, but not as far as the other side. Pistons were all over the place before this.

No air after releasing lever and nothing for the few bleeds afterwards either.
Stainless lines-stock MC-aftermarket lever-no noticeable loss of pressure or response in lever all morning.
Sight glass is full of fluid when upright with bars straight, but about half full when bike is on kickstand with bars in full left lock.
Since I'm not certain if it is leaking or just fluid coming out of the cracks during bleed spillage, I have not tested an emergency stop yet...just slow 30-0 MPH. I can definitely tell the stopping power has been greatly improved even with how little I've pulled the lever, but I want to make sure the system is 100% good to go before I do any potential tests.
Click to expand...

Ok good
And as long as the pistons are even on each side, that's fine, they don't have to push out equal distance on both sides.
At this point, if you had a leak, you should see a noticeable amount of fluid, or even a puddle, as well be losing lever pressure.
It really does sound like you're seeing some spilled fluid from the bleed.
I'de get a can of brake cleaner from an auto-parts store or walmart, and hose down each caliper from the top, while holding a rag under it to catch the drips.
That stuff cleans excellent an evaporates quickly, and will get rid of any left over fluid.
I'de also find a safe place to do an emergency stop or two, where down-shifting and the rear brake can slow you safely, in the unlikely event of front brake failure.
It does sound like everything is ok now too, but I understand the concern...gotta love things like this, lol
 
sixpack577 said:
Ok good
And as long as the pistons are even on each side, that's fine, they don't have to push out equal distance on both sides.
At this point, if you had a leak, you should see a noticeable amount of fluid, or even a puddle, as well be losing lever pressure.
It really does sound like you're seeing some spilled fluid from the bleed.
I'de get a can of brake cleaner from an auto-parts store or walmart, and hose down each caliper from the top, while holding a rag under it to catch the drips.
That stuff cleans excellent an evaporates quickly, and will get rid of any left over fluid.
I'de also find a safe place to do an emergency stop or two, where down-shifting and the rear brake can slow you safely, in the unlikely event of front brake failure.
It does sound like everything is ok now too, but I understand the concern...gotta love things like this, lol
Click to expand...
I pray you're right! Pulled the inspection plates, wiped down the rotors, and dried out the inside of the bleed nipples. We'll see if anything shows up before I leave work in 3hrs, after I get home, and tomorrow morning. Pistons are even on both sides, but the outside is definitely not having to travel as far.
thumbnail_20250401_110239.jpg
 
BlueBacon said:
I pray you're right! Pulled the inspection plates, wiped down the rotors, and dried out the inside of the bleed nipples. We'll see if anything shows up before I leave work in 3hrs, after I get home, and tomorrow morning. Pistons are even on both sides, but the outside is definitely not having to travel as far.
View attachment 1697086
Click to expand...
The Busa and most sportbikes have 'floating' rotors, and that is why the rotor buttons should be loose.
As the rotors aren't solid mounted to the wheel, and even with straight wheels and rotors, the rotors have slight movement, as well as heat expansion.
The calipers of course are solid mounted to the fork legs, but with the rotors having some give, and the fact that pads Do drag on the rotors, you will rarely ever see the exact same piston travel on both sides of the caliper, just as long as the pistons on each side are even, which shows that none are sticking.
I think you're good, and I hope it is.
Let us know.
 
Right caliper bleed bolt oozing fluid from threads...not nipple. Yep, I put 1.5 wraps of plumbers tape on the new bleed bolts.
Pulled it (MC lid on), put on original bare bleeder, and bled system again. Maybe 4 microscopic bubbles...I'll update if that did it finally.

Other occasional issue: ABS like shudder when nearing the end of braking. Only happens during the last second of braking...had this before the rebuild too. Happens more commonly at low speeds and slowly pulling lever.
 
BlueBacon said:
Right caliper bleed bolt oozing fluid from threads...not nipple. Yep, I put 1.5 wraps of plumbers tape on the new bleed bolts.
Pulled it (MC lid on), put on original bare bleeder, and bled system again. Maybe 4 microscopic bubbles...I'll update if that did it finally.

Other occasional issue: ABS like shudder when nearing the end of braking. Only happens during the last second of braking...had this before the rebuild too. Happens more commonly at low speeds and slowly pulling lever.
Click to expand...
So you are getting a brake shudder?

Did you apply any brake slider lube to the pins and pad sliders?

I normally put a thin film on the piston faces as well...
 
BlueBacon said:
Right caliper bleed bolt oozing fluid from threads...not nipple. Yep, I put 1.5 wraps of plumbers tape on the new bleed bolts.
Pulled it (MC lid on), put on original bare bleeder, and bled system again. Maybe 4 microscopic bubbles...I'll update if that did it finally.

Other occasional issue: ABS like shudder when nearing the end of braking. Only happens during the last second of braking...had this before the rebuild too. Happens more commonly at low speeds and slowly pulling lever.
Click to expand...

Wow, that sucks, but at least you found it.
 
Bumblebee said:
So you are getting a brake shudder?

Did you apply any brake slider lube to the pins and pad sliders?

I normally put a thin film on the piston faces as well...
Click to expand...
I'd say yes to the shudder...it's very brief, not all the time, and only at the very last bit of braking.

I only greased the pins with what was left on my gloves. I'll pull the pins and put a better coat on them, as well as the back of the pads since they will be out.
 
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