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  #21  
Old 2 Weeks Ago
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I've never found Brembo rears hard to bleed. I just put the bike on a box-stand, remove the shock and use a tie-down to put the rear wheel into full bump. Leave it there for ten minutes with the bleed nipple open, and then bleed as normal. I've never used the vac bleeder on a rear brake ever.

The M/C sounds like it's turned a cup SB, whack a kit through it mate.
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  #22  
Old 2 Weeks Ago
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Didn't hav any dramas last time I bled it with vac pump n normally. No probs with 300s older bigger style rear brembo either. Is it the MC or caliper seal that's failed? Definitely not doubtin your knowledge nutty but seems like the piston seal is bypassing?
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  #23  
Old 2 Weeks Ago
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Quote:
Originally Posted by shawbagga View Post
Is it the MC or caliper seal that's failed? Definitely not doubtin your knowledge nutty but seems like the piston seal is bypassing?
The only way a slave cylinder doesn't move with a good, properly bled M/C is for the fluid to be going on the floor OR the M/C hydraulic locking. If the M/C is not 'hydraulicing' and the S/C is not moving, the M/C is the issue.
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  #24  
Old 2 Weeks Ago
Marty MOOSE Marty MOOSE is offline
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Quote:
Originally Posted by shawbagga View Post
Think mine is rooted. Can't build pressure at all after normal bleeding, reverse bleeding n takin MC cylinder off n holding at highest point. Get clear fresh fluid cumin thru with no bubbles wen nipple cracked n MC level drops as per routine bleed.

Don't know wat I'm looking at with brakes but guessing MC seal has gone? Nothin at pedal. Pads, pins n slider pins all good/free. 2013 husky wr125 brembo(same brake as ktm). Bike unused for 5 months
Shawbagga just go buy yourself a nice new BETA problem solved, you know you want to.

MM
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  #25  
Old 2 Weeks Ago
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Originally Posted by Marty MOOSE View Post
Shawbagga just go buy yourself a nice new BETA problem solved, you know you want to.

MM
Yes Marty, yes I do. I've already told ram he's my first n only stop for a new bike. Hopefully this year.
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  #26  
Old 2 Weeks Ago
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Quote:
Originally Posted by Nutty View Post
The only way a slave cylinder doesn't move with a good, properly bled M/C is for the fluid to be going on the floor OR the M/C hydraulic locking. If the M/C is not 'hydraulicing' and the S/C is not moving, the M/C is the issue.
Copy that sir, MC rebuild kit it is.

Err sorry to drag this thread on but how do u get it(MC) apart? Circlip at bottom I assume?
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yep
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  #28  
Old 2 Weeks Ago
Fredo Fredo is online now
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Quote:
Originally Posted by Nutty View Post
I've never found Brembo rears hard to bleed. I just put the bike on a box-stand, remove the shock and use a tie-down to put the rear wheel into full bump. Leave it there for ten minutes with the bleed nipple open, and then bleed as normal. I've never used the vac bleeder on a rear brake ever.
I understand the idea why you are lifting the rear end higher than the master cylinder. But I've never had problem bleeding car brakes and the master cylinder is always higher than the wheel cylinders?
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  #29  
Old 2 Weeks Ago
Motoxfox Motoxfox is offline
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'I understand the idea why you are lifting the rear end higher than the master cylinder. But I've never had problem bleeding car brakes and the master cylinder is always higher than the wheel cylinders?understand the idea why you are lifting the rear end higher than the master cylinder. But I've never had problem bleeding car brakes and the master cylinder is always higher than the wheel cylinders?"


Cars - The MC / fluid level is at the highest point and falls all the way to each caliper/ bleeder.
With a bike it can vary AND commonly there is a routing of the line ( front or rear) where the line is near to the same level as the FLUID in the MC.... bingo air will rise to the highest point and become trapped there. That I have found is the major issue. And off road disc brakes are non powered, small piston short throw so again it doesnt ake much to upset the status quo.

I would Follow Nutty's advice as there is something not quite right with this causing having so much trouble.
And that to me means its time to go right thru the system till you positively find the problem OR can positively say that it IS absolutely as per spec.
Something will show up you just need to keep looking - so I would start with the MC and check everything as you go.

ALSO with the caliper off check the run out in the disc. Hold the butt end of a screw driver clamped to the s/arm close to the disc and spin it ( yes it should be mic'ed with a dial gauge)... if the runout is visible this will also give the symptom of zero brake pressure, and / or having to pump up the brake two to three stabs to get brake feel.
Ive had it on a front disc ('12 350 EXCF ) that must of been 'hit' in deep ruts,and became excessivley warped or too much runout.

This issue didnt show up mid ride but raised its ugly head after a 3/4 week lay off... in the shed .... check pre-ride...WTF no front brake!

However the symptom was not zero lever pressure, but having to pump up the brake as it wouldnt 'hold pressure'. In effect the warped disc was pushing 'out' the brake pads excessively and therefore the first pull on the lever meant a full stroke of the m/c piston was insufficient to return push the caliper piston out enough to re-engage the pads against the disc and give 'brake lever feel'.

Hope this helps.GL
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  #30  
Old 2 Weeks Ago
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Nah brake disc is sweet. Yep the hose where it curves back to the MC at front of swingarm is a high point that would likely trap air. MC kit will be on it's way to me soon(as I order it)

Never damaged a disc that bad but enough to feel a pulse thru lever that means it not hetero anymore.
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