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Discussion Starter #1 (Edited)
Brakes - Issues solved!

For some reason, my bike has always stopped fine but I have never had a hard lever. I have put at least 16oz of fluid through it trying to get it firm but I am starting to think calipers are next. I have Ferodo XRAC pads, SS lines, and now a ZX10R Radial M/C.

It still has a spongy feel to it. Bled it again and again over the last two days and bought a mityvac to help out. 16oz of fluid later, still a spongy lever. The brakes start working within about 1/4" of travel but are spongy from there as I can pull the lever close enough to the bar to almost touch my fingers. Now the craziest part of all this is that the bike stops fine and while testing, I can lock the front wheel.

Looked up the pistons and seals and such on Ron ayers and it would be cheaper to buy ZX14 calipers than to rebuild the radials on my '05. Also saw a few threads about greasing the seals with red grease. Is that the next step? Gonna do the zip tie on the lever/bar again tonight...

PS
My comparison for lever hardness are the bikes sitting on the showroom floor. Felt everything from a gixxer to a duc and they all felt solid and firm. Granted the R1's come with Brembo M/C stock but still.
 

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Several here have experienced the problem(s) you describe... I think the best result was had by doing exactly what you're planning... Zip-tie or rubber-band the lever to the grip overnite (mebby a few times)... Sorry I'm no more help!!
 

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For some reason, my bike has always stopped fine but I have never had a hard lever. I have put at least 16oz of fluid through it trying to get it firm but I am starting to think calipers are next. I have Ferodo XRAC pads, SS lines, and now a ZX10R Radial M/C.

It still has a spongy feel to it. Bled it again and again over the last two days and bought a mityvac to help out. 16oz of fluid later, still a spongy lever. The brakes start working within about 1/4" of travel but are spongy from there as I can pull the lever close enough to the bar to almost touch my fingers. Now the craziest part of all this is that the bike stops fine and while testing, I can lock the front wheel.

Looked up the pistons and seals and such on Ron ayers and it would be cheaper to buy ZX14 calipers than to rebuild the radials on my '05. Also saw a few threads about greasing the seals with red grease. Is that the next step? Gonna do the zip tie on the lever/bar again tonight...

PS
My comparison for lever hardness are the bikes sitting on the showroom floor. Felt everything from a gixxer to a duc and they all felt solid and firm. Granted the R1's come with Brembo M/C stock but still.
Hi,

I was in the same position a while ago with my brakes on my 2k 12r, what i did was strip a rebuild my calipers. With my calipers i just removed the existing seals and cleaned everything, i especially paid attention to the seal seats because what happens is dirt/grime builds up causing the seals not to work properly, hense a soft lever. Once cleaned i put them back in and covered them in red rubber grease along with the pistons and rebuilt the calipers, i can now brake with 1 finger no problem at all.
 

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Discussion Starter #4
Hi,

I was in the same position a while ago with my brakes on my 2k 12r, what i did was strip a rebuild my calipers. With my calipers i just removed the existing seals and cleaned everything, i especially paid attention to the seal seats because what happens is dirt/grime builds up causing the seals not to work properly, hense a soft lever. Once cleaned i put them back in and covered them in red rubber grease along with the pistons and rebuilt the calipers, i can now brake with 1 finger no problem at all.
I figured this had to be it... Will pull it apart tomorrow if I get a chance and start over after cleaning everything. Found a few threads about not having to fully rebuild the calipers just clean.

Thanks
 

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Take apart both calipers and clean all the pistons and seals using BRAKE FLUID only. Also, use brake fluid as lube!!! You don't want anything other than brake fluid touching the brake parts or getting into the calipers.

With that being said, don't touch the seals with bare hands, the oils on your fingers are not good. Best to use rubber gloves... especially when using brake fluid to lube and clean the seals (that stuff burns! lol).

Put it all back together and install accordingly. Make sure you bleed the brakes properly. I recommend using a clear tube attached to the bleeder needle going into a catch can, then pump the brakes for full pressure and quickly crack open the needle to release the air bubbles, then quickly tighten the needle. Repeat this on both calipers until there are no more bubbles.

That's just how I was taught to do it, and I haven't seen a better way to do it yet.
 

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Discussion Starter #6
Take apart both calipers and clean all the pistons and seals using BRAKE FLUID only. Also, use brake fluid as lube!!! You don't want anything other than brake fluid touching the brake parts or getting into the calipers.

With that being said, don't touch the seals with bare hands, the oils on your fingers are not good. Best to use rubber gloves... especially when using brake fluid to lube and clean the seals (that stuff burns! lol).

Put it all back together and install accordingly. Make sure you bleed the brakes properly. I recommend using a clear tube attached to the bleeder needle going into a catch can, then pump the brakes for full pressure and quickly crack open the needle to release the air bubbles, then quickly tighten the needle. Repeat this on both calipers until there are no more bubbles.

That's just how I was taught to do it, and I haven't seen a better way to do it yet.
Awesome, thanks! I was gonna go look for some red grease that was mentioned in the other threads but brake fluid sounds much easier and safer...
 

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Just a thought on my old GPZ1100 I had a similar problem after overhauling the brakes, new seals etc and pads and no matter what I did I had soft brakes.
Look @ the picture below.

Turned out my disks had gone dish shaped, old pads had bedded in but when I fitted the new ones they sat miles away from the disks, and only touched in 1 spot...the high spot Now when I applied the brake all it did to start with was straighten the disk out then start braking, but by this time I had lost all my travel. Fitted some second hand disks from fleabay and brakes were perfect there after.
 

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Discussion Starter #9
Ok so it wasn't the calipers... Still have the same feel as before. The pistons were pretty easy to clean because it seems like the radial caliper pistons have some kind of coating. Most of the brake dust crud came off with light rubbing and the rest came off with a fingernail and brake fluid.

But something I did find VERY intresting was while bleeding the brakes after getting it all back together, I was drawing about 15" of vacuum and the cracking the bleeder while pulling the lever. Once the container for the mity vac was almost full, the fluid looked less clear than when it went in. So to test a theory I saw during my searches, I pulled about 25" of vacuum and watched the fluid appear to magically grow bubbles of air out of nowhere!!

They all started slowly rising to the top of the container and after a few minutes, the fluid was clear. I devised a way to draw vacuum on the master cylinder (like I saw in a thread) and left it sitting... My theory is that under pressure/vacuum, the air bubbles are forced together and then since they are now larger, rise easier. Its been about two hours and its still at 25" so I'll release the vacuum in about another hour and then do the zip tie lever trick again tonight.

If all of this doesn't produce anything tomorrow, I am going to relax and get used to it. Like I said, it works fine but I just wanted a harder lever. The 10R master is 11/16 compared to 5/8 for the stock one so maybe that has something to do with it.

PS
Pad wear was even all the way around...
 

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Discussion Starter #10
After more curiousity about the bubbles in the drained fluid, I put my internet searching ability to work and found out that brake fluid has air dissolved into it. Didn't make sense to me either and I wouldn't have believed it if I didn't see it myself.

Vacuum causes the air/fluid to expand enough to cause the air bubbles to merge and rise. Pressure forces the air in the fluid and dissolves it. That explains the zip tie method and why it works so well but is sometimes temporary.
 

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The 10R master is 11/16 compared to 5/8 for the stock one so maybe that has something to do with it.

Could be this as the smaller master will displace less oil per stroke, so in effect your initial lever movement might be just making the pads come into contact with the disk and before you know it you have used half your lever travel before you even get round to braking. On the other forum I use there are some people who add a washer in front of the piston which also removes any slack movement within the lever ?.
Hope you resolve it; as it can be frustrating :headscratch:
 

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Its not necessaily a warped disc that can cause a soft lever, if the disc isn't mounted flat on the hub its the same effect. When I was havng these problems I found that where I had had my rims poweder coated there was a slight lip on the edge of the hub where the paint was overhanging. Once I sanded that down my lever was ok.
 

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Rick Beggs From RnR Cycles here, Ali asked me to reply.
You esentially have the same brake setup as the ZX10, or the new zx14 now. you should have a lever that feels the same. Do not settle for less. Some after market levers do not have the same ratio as stock, and some have the brass bushing drilled too deep, both of which will give you bad feel. If you still have a stock lever, be sure to try it with that.
If you are using the stock one, and still have a soft lever, then back to bleeding. there must be air somewhere.
 

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Discussion Starter #15 (Edited)
Rick Beggs From RnR Cycles here, Ali asked me to reply.
You esentially have the same brake setup as the ZX10, or the new zx14 now. you should have a lever that feels the same. Do not settle for less. Some after market levers do not have the same ratio as stock, and some have the brass bushing drilled too deep, both of which will give you bad feel. If you still have a stock lever, be sure to try it with that.
If you are using the stock one, and still have a soft lever, then back to bleeding. there must be air somewhere.
I agree about the air, its just a matter of finding it... Been through about 20oz of fluid so far and since the brakes work, I am going to leave it alone until I finally decide to get new calipers. One thing I did notice is what you pointed out last time I was there. Pads are at 30-40%...

Tried taking the calipers back off today and holding them so the bleed was at the highest point. Then tried pulling a vacuum on the master, releasing, and then bleeding. Last thing I may try is cracking the banjo while pulling the lever. Probably should have done that first.
 

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I agree about the air, its just a matter of finding it... Been through about 20oz of fluid so far and since the brakes work, I am going to leave it alone until I finally decide to get new calipers. One thing I did notice is what you pointed out last time I was there. Pads are at 30-40%...

Tried taking the calipers back off today and holding them so the bleed was at the highest point. Then tried pulling a vacuum on the master, releasing, and then bleeding. Last thing I may try is cracking the banjo while pulling the lever. Probably should have done that first.
This is an interesting post but im sure you will get there.

When you tie your lever up for a while and then release it, is your brake solid...? and then after a little time it goes back to how it was..? if so i think you have air in your calipers

An idea just popped into my head on testing for air or even an air leak. take both of your calipers off, with the pads in push your pistons back in on both calipers then find two pieces of long metal of even width thats thicker than your discs (like two spanners) and place them between your pads on both calipers, then pump your brake lever until the pads close into what ever you have used and keep pumping until your lever goes hard,(do all this with the calipers off) I might be wrong but im willing to take a bet that your lever travel has gone and the brakes are solid...? . i have done this on several bikes and found that the seals are leaking air.

hope this helps
 

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Discussion Starter #17
Alright last post about this until I get new calipers... :-(

Cracked the banjos while pulling the lever and got a little fluid out. Lever still very similar to what it was. Starts braking within 1/4" but with force, I can pull the lever to the bar. While testing, locked the front up twice. Also looking into getting 320mm rotors put on and will probably do it at the same time as the calipers. If I still have a soft lever after the calipers, the bike will be dropped off at RnR for diagnosis as I am out of ideas...

Thanks for all of your help guys!
 

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I put stainless lines on mine and it helped, but still wasn't 100%...

Then a friend told me about the "zip tie to the bars o-night" trick, I damn near endo'ed the first time I grabbed a handfull.

It worked great for me. BIG difference.

I do it the night before every track day now.

EDIT: also if you think youve got air trapped, you can tap VERY LIGHTLY on the caliper with a PLASTIC OR RUBBER mallet, while the lever is zip tied back. This will help the air thats clinging to the walls break loose and migrate up to the mc. VERY LIGHTLY, youre just trying to provide some vibration, not bend anything... hope this helps.
 

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I had a similar problem, after changing brake pads & cleaning the brake pistons.
Symptoms were spongy feel, with way to much brake lever travel.
Scary to ride, as I wasn't used to the brakes not pulling the speed down until the last possible moment.

Like you had bled the brakes several times, all to no avail.

Here's what I found and what finally worked for me.

First there is air trapped in the system. Somewhere, & it's enough to cause the spongy feeling.
In my case the air was trapped in the right caliper.
To resolve this problem I removed the bottom caliper bolts.
Loosened the top caliper bolt enough to rotate the caliper like a hinge. (2000 calipers)
Tapping on the caliper with the plastic handle of a screwdriver, while moving the caliper up and down.
Had the clear tube attached to the bleeder valve & pumped up the pressure, holding the lever tight, released the bleeder valve & retighten.
Pump the lever & hold, release bleeder valve & retighten.
After doing the above 3 or 4 times the brakes finally came back.

No spongy feel, & stop the way they should.

So find the air in the system…my bet would be…it's hiding in the caliper(s)
 
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