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View Full Version : 2013 rear brake issue, help please



Tekniqs
04-11-2019, 02:26 PM
My rear brakes has no pressure unless I first repeatedly activate the brake numerous times. It gradually builds pressure and then the brakes will eventually bite. keeping it depressed will keep the brakes activated. Once I let go of the rear brakes for about 2 to 3 seconds, the issue returns and there's no rear brake pressure when i depress the rear brake lever on the footpeg. I've flushed the rear brakes numerous times now, probably gone through 15x what the reservoir holds. Any other tips or things I should look into? I've flushed the front brakes on many bikes but this is the first time i've tried doing the rear brakes.

amauri
04-11-2019, 06:01 PM
Did you unbolt the caliper and bleed while holding it upside down and higher than the master cylinder?

Air rises, if you try bleeding air from the lowest point in the system it will never work.

Another common problem is a misadjusted m/c pushrod, do you have aftermarket foot rests and pedals?

SlamDunK
04-11-2019, 06:06 PM
Was just going to say that......
Another trick is to push the pistons as far back as they'll go and keep them there while you bleed the air.
Just remember to top up fluid as you get them back in to position.

Tekniqs
04-11-2019, 07:17 PM
Did you unbolt the caliper and bleed while holding it upside down and higher than the master cylinder?

Air rises, if you try bleeding air from the lowest point in the system it will never work.

Another common problem is a misadjusted m/c pushrod, do you have aftermarket foot rests and pedals?

hey thanks for the reply. yes I did try it that way but will probably give it another go this weekend. yes I have lightech rearsets. Used it for I think almost 2 years before this issue came up though.


Was just going to say that......
Another trick is to push the pistons as far back as they'll go and keep them there while you bleed the air.
Just remember to top up fluid as you get them back in to position.

hmm will have to try that too if the above doesn't work. thanks!

if all else fails...guess i'll bring to a shop lol

SlamDunK
04-12-2019, 03:57 AM
Nah, you'll manage.
Pushing the piston in gets rid of the cavity behind them, fewer places for the air to hide.
Push them in, insert a block or sheets of wood or whatever you have to hand and bleed as amauri suggested.

amauri
04-12-2019, 09:24 AM
yes I have lightech rearsets. Used it for I think almost 2 years before this issue came up though.

even though you've been using it for 2 years, make sure you ck for free play on the pushrod, otherwise the piston is not being fully retracted each time you release the brake.

Tekniqs
04-12-2019, 01:54 PM
thanks for the suggestions guys

marcodarq
04-12-2019, 02:43 PM
as well as doing the things already mentioned, you might check your rear rotor for excessive runout, a warped rotor will give you a similar symptom.
m

SlamDunK
04-13-2019, 12:50 AM
as well as doing the things already mentioned, you might check your rear rotor for excessive runout, a warped rotor will give you a similar symptom.
m

Good call.
Re-reading the initial post, it seems likely.

amauri
04-13-2019, 09:37 AM
.. a warped rotor will give you a similar symptom.

True

But in the case of the rear rotor it is very rare on these bikes.
The only way they ever warp is if the m/c pushrod is missadjusted, causing the brake to drag and over heat.
Or if the rider is unknowingly maintaining foot pressure on the pedal all the time.

Tekniqs
04-14-2019, 01:37 PM
So i removed the rear tire, unbolted the caliper and held it up while bleeding. Definitely helped! I was then going to adjust the push rod to make sure it's adjusted correctly. Went to remove those 'boot guard' things so I can get access to the push rod. My damn hexkey snapped while trying to unbolt it and the head is sitting flush inside the hole so I can't even pull it out lol. Another headache.

winwin
04-15-2019, 04:18 AM
I have the same problem, already bled the brakes and it kinda bites now starting halfway down, but still can't lock the rear or have it activate the ABS. Should I bleed more? Also, which pushrod are we talking about? :/

rcannon409
04-15-2019, 07:17 PM
You don't have access to an air compressor, do you? I fought my rear brake, for hours. I've bleed many brake systems before...cars, trucks, motorcycles, and never had an issue...until this brembo brake. I ordered one of the cheap, air powered blenders from Ebay. 19.88, with shipping, sort of cheap. I hooked it up and it did an amazing job. I don't think I fired the thing more than three times and it did a far better job than I ever did, manually, with the old pump and bleed thing. If you have a compressor, by all means get one.

winwin
04-16-2019, 12:34 AM
You don't have access to an air compressor, do you? I fought my rear brake, for hours. I've bleed many brake systems before...cars, trucks, motorcycles, and never had an issue...until this brembo brake. I ordered one of the cheap, air powered blenders from Ebay. 19.88, with shipping, sort of cheap. I hooked it up and it did an amazing job. I don't think I fired the thing more than three times and it did a far better job than I ever did, manually, with the old pump and bleed thing. If you have a compressor, by all means get one.

Would compressors used for tires work? Also, what do you do with the compressor? Flush the reservoir?