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Discussion Starter #1
Fighting a front brake issue. Can pump front brakes up hard, will stay hard forever. Start driving, squeeze lever 90%to the bar before feel any bite. No leaks, lots of fluid, have bled the **** out of them... Pads like new, only 370km on bike. Calipers all clean, pads seated properly

I'm baffeled

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Dezz has commented that pistons must be completely bottom out to make sure all air is removed from the calipers before bleeding. He's had simular issues witch were resolved by this technique. Give that a try
 

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Dezz has commented that pistons must be completely bottom out to make sure all air is removed from the calipers before bleeding. He's had simular issues witch were resolved by this technique. Give that a try
Why yes I have...lol.

If you have air in the system (which it shouldn't be if you haven't opened up the system), the best solution I found for bleeding is to clamp each caliper piston fully into the caliper using a C-clamp. Have the bleed screw in the most top position (rotate caliper if possible), then bleed it. This procedure works everytime for me now.
 

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AND....I had a bad front wheel bearing causing the rotor to run a few degrees from true through the caliper. This was like riding the brake and the rubbing built a lot of heat and the brakes faded to nothing when needed.
I replaced the bearing and never touched the front brake except to remove the caliper to get to the bearing.
New bearing only and the brakes have not faded again.
 

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Fighting a front brake issue. Can pump front brakes up hard, will stay hard forever. Start driving, squeeze lever 90%to the bar before feel any bite. No leaks, lots of fluid, have bled the **** out of them... Pads like new, only 370km on bike. Calipers all clean, pads seated properly

I'm baffeled

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Just install new pads?
OEM or aftermarket? Aftermarkets are usually manufactured to Chinese tolerances.

You indicated that the pads are seated properly. However the inside pads do jam often even when they seem to be seated properly. Best to file or grind a little off the width of the bottom square tab of the inside pad.

Shouldn't need bleed if you only change out the pads.
I've never had a problem bleeding the tradition method.
Dezz's method definitely does help with stubborn brakes.
 

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Discussion Starter #6
No, not new pads. Original oem, came on bike, still 90+% left on them. I was trail riding, through a mud hole, stopped for lunch, hit trail again and noticed almost zero front brakes. Was informed it could be dirty preventing pad from returning to rest.... Took it all apart, cleaned all dirt and debris out. Same issue. Start bleeding process.... Same issue.
Almost certain it's not an issue with the master as it can be pumped up solid and holds that pressure for as long as you want.... Until you start driving... Then you can squeeze it right to the bar again

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No, not new pads. Original oem, came on bike, still 90+% left on them. I was trail riding, through a mud hole, stopped for lunch, hit trail again and noticed almost zero front brakes. Was informed it could be dirty preventing pad from returning to rest.... Took it all apart, cleaned all dirt and debris out. Same issue. Start bleeding process.... Same issue.
Almost certain it's not an issue with the master as it can be pumped up solid and holds that pressure for as long as you want.... Until you start driving... Then you can squeeze it right to the bar again

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After reading this information, I would suspect bad wheel bearing(s) or bent rotor(s).
 

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How far do you need to ride before you lose the brakes?

Do you have to use the brakes a few times before it happens or does it happen without using the brake?

Are the caliper slide pins clean and free?

Is someone helping you bleed the brake?


Sorry for all the questions.



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Discussion Starter #10
How far do you need to ride before you lose the brakes?

Do you have to use the brakes a few times before it happens or does it happen without using the brake?

Are the caliper slide pins clean and free?

Is someone helping you bleed the brake?


Sorry for all the questions.



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10-20 feet and it will do it. start bike, roll forward or backwards and first squeeze is good since they were firm from us bleeding them. 2nd or 3rd squeeze, soft again. brakes grab well enough on that last 5% to lock fronts up and drag on asphalt at 10-15kph.
pins were juust taken out and inspected and all cleaned up right after it first happened...that was my first thought.
bleed alone first 15 times with rubber ziptie on bar at first. went to a coworkers place lastnight.... we made no progress
 

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I do not believe air in the system is your issue. Air in the system will never get a hard handle or lockup the tires. Not would air get into the system from just riding it. The system would have to be opened up. You have a mechanical problem in my opinion.

You are 100% sure wheel bearings are tight with no play whatsoever?
And are 100% sure the rotor is not warped?

Do you have metal skid plates? If so, have they been bent and touching a brake caliper with weight on the wheels, pushing the caliper back?
 

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Discussion Starter #14
I do not believe air in the system is your issue. Air in the system will never get a hard handle or lockup the tires. Not would air get into the system from just riding it. The system would have to be opened up. You have a mechanical problem in my opinion.

You are 100% sure wheel bearings are tight with no play whatsoever?
And are 100% sure the rotor is not warped?

Do you have metal skid plates? If so, have they been bent and touching a brake caliper with weight on the wheels, pushing the caliper back?
air in system will still allow solid brakes and lock tires up. only reason i argue this point is my buddy with a new 2019 850 outlander just over 800 miles, just suddeny lost brakes on a dirt road, no leaks, another friend helped him bleed all brakes and saw air bubbles. this was from factory. I personally test drove his bike for about 30 min while he tried mine.his brakes worked great then. 2 weeks later they had to bleed them to get them working again.


now with mine m sure of good bearings and rotors, but if rain stops tomorrow, ill pull wheels and again tripple check just to be 110% sure
 

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When the calipers get clogged with mud and maybe some gravel the ends of the pads can be block from moving. The piston will bend the pads. This can cause the pads to hang up.

While you have it apart file a little off the width of those tabs. You got nothing to lose.

Because your issue is immediate I don't feel your bearing or rotors are bad. Bent or bad bearings and rotors cause brake dragging which cause heat that boils the brake fluid. Also you would most likely feel pulsing in the brakes.
 

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Discussion Starter #16
When the calipers get clogged with mud and maybe some gravel the ends of the pads can be block from moving. The piston will bend the pads. This can cause the pads to hang up.

While you have it apart file a little off the width of those tabs. You got nothing to lose.

Because your issue is immediate I don't feel your bearing or rotors are bad. Bent or bad bearings and rotors cause brake dragging which cause heat that boils the brake fluid. Also you would most likely feel pulsing in the brakes.
yeah i cleaned pads really well, made sure they were seated and not binding, as i had read about theirs with the issues. but like you said, nothing t loose, worth a try knocking the edge off... tomorrow after work if the weather cooperates
 

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Discussion Starter #17
Well a bit of an update... Sibs the weaker I isn't cooperative, I haven't had a chance to pull the wheels and calipers and clean and lube everything again. So I squeezed the lever, put azip tie on it and left it over night..... Well over night turned into over 38hours.lol

This didn't solve the problem but it seemed to help, lever is soft, to abot 75% then it bite, age I can squeeze it a few times and will pump back up firm... Then goes soft to around 75% after using when moving.

So this to me says there is definitely air in there, age these are just a bitch to bleed... Or am I wrong?

Press chime in

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Here is two ways that I bleed the brakes on an ATV.
I have gravity bled my front brakes before.
Just remove reservoir cover,
attach a clear vinyl tube to the bleeder crack one open and let drain,
add fluid as needed,
no bubbles,
close bleeder then do the other side.

Traditional bleeding..
I do not pump up the brakes.
Open reservoir fill if needed,
With a tube in a container open one bleeder, pull and hold lever, close bleeder, repeat until no air bubbles. Add fluid as needed.
Move to the other side.
 

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Discussion Starter #19
yeah plan is to try gravity bleed but it's been raining so much and i haven't rebuilt my shed that collapsed under snowload last winter. so i'm working outside and don't want to introduce moisture to the system.
 
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