My rear brake doesn't work?!

Graugaard · March 15th, 2012, 05:27 AM

Hey guys! troubles troubles troubles...

Al right, my rear brake doesn't work. When i press down the brake it says "pffftt" and the brake caliper dosen't move onto the disc at all. The pedal is very easy to press on. Like there is no resistance at all, only the spring makes it jump back to place.

Brake fluid is full and clean.

hope you guys can help me. hate driving without the rear brake

dubojr1 · March 15th, 2012, 10:56 AM

Blown seal/seals inside the master cylinder. Time for a rebuild.

k-os · March 15th, 2012, 03:18 PM

Try bleeding any air from the lines first.

flynjay · March 15th, 2012, 03:27 PM

Have you done recent maintence, or is this something that has developed over time?

Motofool · March 15th, 2012, 05:20 PM

Can you see any leak of brake fluid along the hose or at the caliper?

LoD575 · March 15th, 2012, 08:56 PM

The hydraulic system has no pressure. Seeing how you state the fluid is clean I am guessing new fluid recently and there is either air in the line or a blown seal in the master cylinder.
Either problem is not allowing the fluid system to compress/displace which activates the caliper.

flynjay · March 15th, 2012, 09:16 PM

I was thinking one of your pads was stuck on the guide or you have the pads in wrong. Double check that the pads are making good contact with the rotor and are free to move.

Happened to me when I changed the rear tire.

Graugaard · March 16th, 2012, 12:13 PM

Quote:

Originally Posted by LoD575

The hydraulic system has no pressure. Seeing how you state the fluid is clean I am guessing new fluid recently and there is either air in the line or a blown seal in the master cylinder.
Either problem is not allowing the fluid system to compress/displace which activates the caliper.

Indeed im also 95% sure that this is my problem! How can i fix this?

LoD575 · March 16th, 2012, 12:32 PM

Quote:

Originally Posted by Graugaard

Indeed im also 95% sure that this is my problem! How can i fix this?

Pump the rear brake pedal several times, hold it, then open the caliper bleeder valve.
If you have air in the line this method will remove it from the system.

This process should be performed multiple times as needed to purge air from the system and keep an eye on the rear reservoir filling it as needed.

If the above process does not improve the rear brake the problem could be a blown seal in the master cylinder itself which would require removal and rebuilding.

What has recently been done to the rear brake system?

Graugaard · March 16th, 2012, 02:40 PM

Quote:

Originally Posted by LoD575

Pump the rear brake pedal several times, hold it, then open the caliper bleeder valve.
If you have air in the line this method will remove it from the system.

This process should be performed multiple times as needed to purge air from the system and keep an eye on the rear reservoir filling it as needed.

If the above process does not improve the rear brake the problem could be a blown seal in the master cylinder itself which would require removal and rebuilding.

What has recently been done to the rear brake system?

I took my brake calliper off the disc for the first time, when i should remove the rear wheel, cus i needed new tire. I opened up for the wrong screw, so brake fluid came out of the calliper. I tightened it up again, and i actually think it was after that, the whole system was defect.

LoD575 · March 16th, 2012, 02:50 PM

Quote:

Originally Posted by Graugaard

I took my brake calliper off the disc for the first time, when i should remove the rear wheel, cus i needed new tire. I opened up for the wrong screw, so brake fluid came out of the calliper. I tightened it up again, and i actually think it was after that, the whole system was defect.

Probability air is in the line causing the problem. Check to make sure the pads and caliper are not binding and bleed the system to remove and trapped air.

k-os · March 16th, 2012, 03:30 PM

Quote:

Originally Posted by Graugaard

I took my brake calliper off the disc for the first time, when i should remove the rear wheel, cus i needed new tire. I opened up for the wrong screw, so brake fluid came out of the calliper. I tightened it up again, and i actually think it was after that, the whole system was defect.

Be careful messing around with your brakes if you're not exactly sure of what you're doing. Might have to ask a friend to help out if you have one that's familiar with bikes.

March 15th, 2012, 05:27 AM	#1
Graugaard ninjette.org member Name: Elias Location: Denmark Join Date: Nov 2011 Motorcycle(s): Ninja 250r Posts: 152	My rear brake doesn't work?! Hey guys! troubles troubles troubles... Al right, my rear brake doesn't work. When i press down the brake it says "pffftt" and the brake caliper dosen't move onto the disc at all. The pedal is very easy to press on. Like there is no resistance at all, only the spring makes it jump back to place. Brake fluid is full and clean. hope you guys can help me. hate driving without the rear brake

March 15th, 2012, 10:56 AM	#2
dubojr1 ninjette.org certified postwhore Name: Jason Location: Jacksonville, Florida Join Date: May 2010 Motorcycle(s): 09 Ninja 250R SE, 07 Honda CRF230F, 06 Honda CRF150F Posts: A lot.	Blown seal/seals inside the master cylinder. Time for a rebuild. __________________________________________________ 09 250R SE: Paying it forward one post at a time! Don't forget to add yourself to our Member Map

March 15th, 2012, 05:20 PM	#5
Motofool Daily Ninjette rider Name: Hernan Location: Florida Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot. MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16	Can you see any leak of brake fluid along the hose or at the caliper? __________________________________________________ *Motofool* *.................................Never ride faster than your guardian angel can fly* "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí

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March 15th, 2012, 03:18 PM	#3
k-os ninjette.org sage Name: Andy Location: Sheboygan, WI Join Date: Dec 2008 Motorcycle(s): 1988 Honda Hawk NT650, 1989 Honda Hawk NT650, 1997 GSXR750 Track Bike Posts: 890	Try bleeding any air from the lines first.

March 15th, 2012, 03:27 PM	#4
flynjay ninjette.org guru Name: Jason Location: Houston, TX Join Date: Nov 2011 Motorcycle(s): 2007 Ninja 250 (sold), '06 Ninja 650R Posts: 455	Have you done recent maintence, or is this something that has developed over time?

March 15th, 2012, 08:56 PM	#6
LoD575 ninjette.org sage Name: Steve Location: Valdosta GA, US Join Date: Jul 2011 Motorcycle(s): 2012 Ninja 250, 2006 Ninja ZX6R-636 Posts: 661	The hydraulic system has no pressure. Seeing how you state the fluid is clean I am guessing new fluid recently and there is either air in the line or a blown seal in the master cylinder. Either problem is not allowing the fluid system to compress/displace which activates the caliper.

March 15th, 2012, 09:16 PM	#7
flynjay ninjette.org guru Name: Jason Location: Houston, TX Join Date: Nov 2011 Motorcycle(s): 2007 Ninja 250 (sold), '06 Ninja 650R Posts: 455	I was thinking one of your pads was stuck on the guide or you have the pads in wrong. Double check that the pads are making good contact with the rotor and are free to move. Happened to me when I changed the rear tire.