[Tmoore636]

Hey guys, so im back with another problem (go figure)
Recently, i hit a tap on the highway and busted my tire, luckily i didn't fall. I took the tire off, and had it replaced but when i put it back on, the rear brakes were very weak and the lever had alot of slack in it before it would actually apply braking power.
Im an electronics guy, i know barely anything about how to bleed brakes, and let a friend do it, but i believe we did it wrong and air got into the line. After attempting to bleed them, they completely stopped working.
Today, my father and i bled the lines the proper way, but still had no luck. No matter what i do, the lever will not move the pads to start braking. I see that they are very close to the rotor, but they aren't scrubbing. i have no idea if this is normal, as i've never really examined them. as i said, ive never messed with the brakes on my bikes.
Any ideas on a fix? they worked perfectly before the tire change.

Also, this happened on my ninja 250 when i changed the rear tire, but that bike went through hell and the back brakes weren't that good even before i changed the tires.

 

[trackdayhero]

When you take the wheel off to change the tire you reset the puck a ways back into the caliper when you put the wheel back on for the rotor to slip between the pads. If after you put the rear wheel back on you don't pump the brake pedal a few times to get the pads back up against the rotor you're going to have no rear brake the first time you go to use it. But, once you pump it a few times it should be back against the rotor and feel fine. That shouldn't cause them to feel weaker. But if they do feel weak the first thing you would do is bleed them. But again, changing the rear wheel and resetting the puck shouldn't cause air to get into the system.

 

[Tmoore636]

How do you do that?
I improperly bled the system, im sure that is the reason the air was in the line. The brakes worked after the tire change, but after i "bled" the line, they quit

 

[trackdayhero]

Ah, sorry read through your message too quickly and didn't see the part where you bled the line. There are a few ways to bleed the brake either manually or by using a vacuum tool. I have a vacuum tool that makes it easier but you don't need that. Fill your reservoir and put a piece of clear tube on the bleed nipple. Press down on your brake pedal, open then close the bleeder valve which will cause a certain amount of fluid to come out and your brake pedal will go down. Make sure you close the bleeder before releasing the pedal. Repeat this over and over until you get all the air out. Keep an eye on the reservoir so the level doesn't get too low.

 

[Tmoore636]

Yeah, i did a proper bleeding today. just not sure how to reset the puck

 

[spiderman636]

You dont need the rear brake anyway. screw it. seriously


But if you really want to try to fix it then understand how a brake system works. Fairly simple mechanisms. You push the lever. The lever pushes fluid threw the system which cause the pistons to come out, ultimately pushing the pads out, against the rotor to cause you to stop. My suggestion is bleed them again and make sure all of your bleeder nipples and bolts are tight and you arent losing air anywhere. If you still have the rubber lines, inspect them and be sure the person that changed your tire didnt damage them.

Before you do all of that pump the lever a ton of times. I am not sure if this will do anything but do it. It always makes me feel better.

 

[trackdayhero]

Yeah, i did a proper bleeding today. just not sure how to reset the puck

If you properly bled it you don't have to reset the puck, it will already be against the rotor and the brake will work fine.

 

[Tmoore636]

I pumped the hell out of them, bled them, did everything you guys said minus taking the tire back off and pushing the pads all the way back.
I opened the petcock slightly, stuck a small flathead in between the pad and rotor, and made a decent sized space between them.
Pressed the brake, and it works ALITTLE, but it has to be COMPLETELY depressed to just slightly start grabbing. Pressing them in doesnt seem to change anything going on in the piston.
After i moved the pad out, i bled the system. pump brakes, hold, open bleeder, close bleeder, pump pump pump, repeat.
Still no luck.
I need my back brakes, i don't want to fall from sudden braking

 

[spiderman636]

I was being serious when I said you dont need the rear brake.

That being said though, your bleed technique seems off if I am reading your posts correctly.

Open bleeder, press brake, close bleeder, decompress brake, repeat.

I pumped the hell out of them, bled them, did everything you guys said minus taking the tire back off and pushing the pads all the way back.
I opened the petcock slightly, stuck a small flathead in between the pad and rotor, and made a decent sized space between them.
Pressed the brake, and it works ALITTLE, but it has to be COMPLETELY depressed to just slightly start grabbing. Pressing them in doesnt seem to change anything going on in the piston.
After i moved the pad out, i bled the system. pump brakes, hold, open bleeder, close bleeder, pump pump pump, repeat.
Still no luck.
I need my back brakes, i don't want to fall from sudden braking

 

[NitrusReigns]

I pumped the hell out of them, bled them, did everything you guys said minus taking the tire back off and pushing the pads all the way back.
I opened the petcock slightly, stuck a small flathead in between the pad and rotor, and made a decent sized space between them.
Pressed the brake, and it works ALITTLE, but it has to be COMPLETELY depressed to just slightly start grabbing. Pressing them in doesnt seem to change anything going on in the piston.
After i moved the pad out, i bled the system. pump brakes, hold, open bleeder, close bleeder, pump pump pump, repeat.
Still no luck.
I need my back brakes, i don't want to fall from sudden braking

I'm slightly concerned what you might mean by the last statement that I bolded when quoting your post...:O

I was being serious when I said you dont need the rear brake.

That being said though, your bleed technique seems off if I am reading your posts correctly.

Open bleeder, press brake, close bleeder, decompress brake, repeat.

Agreed - I'm not sure how your previously explained bleeding process works (if it works), but what spiderman said is what you should be doing when you bleed your brakes. :yes

 

[trackdayhero]

I was being serious when I said you dont need the rear brake.

On the same token you don't need the front brake.

 

[trackdayhero]

I pumped the hell out of them, bled them, did everything you guys said minus taking the tire back off and pushing the pads all the way back.
I opened the petcock slightly, stuck a small flathead in between the pad and rotor, and made a decent sized space between them.
Pressed the brake, and it works ALITTLE, but it has to be COMPLETELY depressed to just slightly start grabbing. Pressing them in doesnt seem to change anything going on in the piston.
After i moved the pad out, i bled the system. pump brakes, hold, open bleeder, close bleeder, pump pump pump, repeat.
Still no luck.
I need my back brakes, i don't want to fall from sudden braking

The only reason you need to reset the puck is to make it easier to get the wheel back on. Once it's on you don't have to mess with the puck again. If you have spongy brakes then it's obvious that you still have air in the system.

 

[Ey3l45h]

On the same token you don't need the front brake.

I stop my bikes with pure will power.

Ey3

 

[spiderman636]

On the same token you don't need the front brake.

I know right. If you think about it, brakes only slow you down.

 

[trackdayhero]

I know right. If you think about it, brakes only slow you down.

I'm just saying. I use both of my brakes and if you go off into the cabbage or get in some gravel that front brake will be useless and that rear brake will save your ass. I use it a lot on the race track as well. But the guy asked how to fix it, not whether he should use it.

 

[spiderman636]

I'm just saying. I use both of my brakes and if you go off into the cabbage or get in some gravel that front brake will be useless and that rear brake will save your ass. I use it a lot on the race track as well. But the guy asked how to fix it, not whether he should use it.

In all fairness I think you're a heck of alot faster than most of us, at least me. I'm not going nearly fast enough to need it. Lol. Hell I was kind of serious about not needing either. Of course sooner or later you need to stop your bike but at my pedestrian pace when I go around the track doing no brakes drill, I don't have to slow my pace very much. I'm slow as shit. Lol

 

[iLean2much]

If you pump the lever with no resistance when doing the bleeding, you might get more air in than out!

first, I'd take the caliper off hold in your hand and pump the lever. After 3-5 pumps the pads should be touching each other... maybe have a screw driver already in the space to push the pads apart again later.

If that didn't do much then I'd say you either have a seized brake piston (43020, big round cylinder behind the one pad) or you have a seized caliper bracket/holder (43044).
Those 2 pins of the holder have rubber accordion boots (49006/49006A) on them that hold grease.
The way the brake works with that holder is, that when you apply pressure on the lever, the piston comes out pinches the rotor between the pads where the smaller outer pad is held in place by the holder. When releasing pressure, the force of the wheel in motion pushes the pads off the rotor. NOW the caliper has to move on those sliders with the grease in the boots in order to get the pad away from the rotor. IF it's misaligned or seized it just won't move much.

Also, if you got too much gas/air in the brake line you won't build enough pressure to move the piston out, usually feels like no resistance or a spongy feeling once you do feel some resistance and could keep pushing the lever beyond the point of resistance.


2005 Kawasaki NINJA ZX-6R (ZX636-C1) Rear Brake | Babbitts Kawasaki Parts House


I'd just go back to where the problem started...
Take the wheel off again to get the caliper. You could loosen the two bolts that hold the caliper on the big holder (43034) that slides in on the swingarm but it's more likely you will brake your tool or strip the bolt before that lets go, if it does come off you'd need lots of lock tight for safety so it won't come off or loose on its own.
Better just to take the wheel off.

Take pads out, pump piston forward, if that comes out too far you'll have a mess of brake fluid on the floor.
Take WD40 and old tooth brush, scrub the crap out of it, move piston in and out manually a few times during scrubbing.

To get the caliper separated from the little holder (43044), just pull on it hard!
For cleaning the boots, make sure the rubber boots are not ice cold (hair dryer?) and squeeze/push the out of the holes in the caliper.
use heavy weight high heat like a wheel bearing grease. If it wasn't high heat, the grease might disappear and flow out/melt. Then you're back to having a seized caliper.


This is a lot of information but the best I can do at the time.

Just take your time with it.

 

[Flash636]

If you pump the lever with no resistance when doing the bleeding, you might get more air in than out!

first, I'd take the caliper off hold in your hand and pump the lever. After 3-5 pumps the pads should be touching each other... maybe have a screw driver already in the space to push the pads apart again later.

If that didn't do much then I'd say you either have a seized brake piston (43020, big round cylinder behind the one pad) or you have a seized caliper bracket/holder (43044).
Those 2 pins of the holder have rubber accordion boots (49006/49006A) on them that hold grease.
The way the brake works with that holder is, that when you apply pressure on the lever, the piston comes out pinches the rotor between the pads where the smaller outer pad is held in place by the holder. When releasing pressure, the force of the wheel in motion pushes the pads off the rotor. NOW the caliper has to move on those sliders with the grease in the boots in order to get the pad away from the rotor. IF it's misaligned or seized it just won't move much.

Also, if you got too much gas/air in the brake line you won't build enough pressure to move the piston out, usually feels like no resistance or a spongy feeling once you do feel some resistance and could keep pushing the lever beyond the point of resistance.


2005 Kawasaki NINJA ZX-6R (ZX636-C1) Rear Brake | Babbitts Kawasaki Parts House


I'd just go back to where the problem started...
Take the wheel off again to get the caliper. You could loosen the two bolts that hold the caliper on the big holder (43034) that slides in on the swingarm but it's more likely you will brake your tool or strip the bolt before that lets go, if it does come off you'd need lots of lock tight for safety so it won't come off or loose on its own.
Better just to take the wheel off.

Take pads out, pump piston forward, if that comes out too far you'll have a mess of brake fluid on the floor.
Take WD40 and old tooth brush, scrub the crap out of it, move piston in and out manually a few times during scrubbing.

To get the caliper separated from the little holder (43044), just pull on it hard!
For cleaning the boots, make sure the rubber boots are not ice cold (hair dryer?) and squeeze/push the out of the holes in the caliper.
use heavy weight high heat like a wheel bearing grease. If it wasn't high heat, the grease might disappear and flow out/melt. Then you're back to having a seized caliper.


This is a lot of information but the best I can do at the time.

Just take your time with it.

Meh.... That's why I love this forum!!! :bigthumb:

 

[Tmoore636]

I've tried all these things, but still had no success. I've taken the tire off, ensured the pads are seated correctly, double checked the piston and it works. The entire system seems to work fine until I reattach it to the swing arm. I've bled the brakes at least 10 times, but they still don't seem to apply any braking power when the lever is pressed.

 

[VULGR]

Post up what area you're in, someone might be generous enough to come and show you how to bleed the brakes properly