Weak front brake


20 replies to this topic
  • flogger

Posted March 22, 2005 - 01:46 PM

#1

Gents,
01 yz 426 and the front brakes have no stopping power. They work but just not well enough. I removed res cap and notice that when I pull the brake lever fluid comes back up into the res. A couple of friends that was with me at the time told me this was not normal. Any suggestions??
Flog

  • Motoman_AZ

Posted March 22, 2005 - 03:05 PM

#2

I have changed the fluid, SS line (shorter & reroute), new brake pads, used a power bleeder and still have shitty brakes. Nature of the beast unless you convert to another brand of MC.

:) :)

  • curtains23

Posted March 22, 2005 - 03:26 PM

#3

Sounds like master cylinder seals, normal yz brakes are good, if you have new pads they all need bedding in, hold hard pressure on the lever if it moves to the bars gently it proves something is leaking, if the pads need bedding in you can tell by looking at the disc, wet it a few times and let it dry between wettings, spin the wheel a few times off the ground and braking gently, this will show where the pads are rubbing,
good luck....CURTAINS23

  • RCannon

Posted March 22, 2005 - 03:33 PM

#4

I agree 100% with the mastercylinder theory. Switch to one off of a Honda CR and it will make a huge difference.

  • grayracer513

Posted March 22, 2005 - 04:02 PM

#5

A small squirt of fluid from the cylinder up into the reservoir IS normal, but just a bit, and just in the first part of the lever travel. It's just pushing fluid out of the fill port until the piston travels past it into the bore of the cylinder.

  • 02YZ426

Posted March 22, 2005 - 04:29 PM

#6

Maybe there is air in the brake line. I would bleed the line and see if that helps.

  • Chas_M

Posted March 22, 2005 - 08:50 PM

#7

Before you do anything drastic, try prying out the brake pad away from the rotor with a large screwdriver them pumping the brake lever until it firms up. Repeat once or twice. What this accomplishes is to back bleed air bubbles out into the reservoir often firming up the brakes.

  • Matt96xr6

Posted March 22, 2005 - 11:14 PM

#8

if you have fluid coming up, there is no air trapped in the MC. I would suggest to bleed out the front brake, get new pads, grease the pins up and try it again.

  • markit

Posted March 25, 2005 - 05:42 PM

#9

Yea I have all kinds of bikes and the yz brakes are as good as any, and actually i was suprised when I first tryed them. So just overlook all the honda goons its all bull, and bleed your lines, check you pads for ware and youll be good.

  • RCannon

Posted March 25, 2005 - 06:13 PM

#10

Seriously, I have never owned a Honda. The insides of the Honda master cylinder are slightly different. The piston is as well. You'll pick up a decent amount of performance by making the switch.

A used honda master cylinder on ebay is cheaper than Yamaha's rebuild kit.

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  • markit

Posted March 26, 2005 - 06:17 AM

#11

Seriously, I have never owned a Honda. The insides of the Honda master cylinder are slightly different. The piston is as well. You'll pick up a decent amount of performance by making the switch.

A used honda master cylinder on ebay is cheaper than Yamaha's rebuild kit.


RC, I wasnt refering to you.lol but I wouldnt put honda parts on a good bike.lol Even you said it (cheaper) :)

  • John_Lorenz

Posted March 26, 2005 - 09:07 AM

#12

Master Cylinder issue

Plus what Fluid are you using?

Aka Dot Type

Do not use Dot 5 it will destroy your seals in a minute it is not compatible with dot 4 or dot 5.1

If you have done this then you probably ate the seals up.

The only time you should use dot 5.1 is in a fresh never before filled system.

Get Motul 600 it is the best and has the highest boil points :)

  • Guest_BrandonV_*

Posted March 26, 2005 - 09:25 AM

#13

My 2000 had horrible front brakes and I mean horrible! They wouldn't even lock up on the mud...

I picked a Nissin MC off ebay that was a leftover from the Cannondale bikes, got a Ride Eng. SS line and some Motul 600 fluid. I couldn't believe how much better it was. I'm sure the fluid and SS line helped, but I believe the MC made the biggest difference.

  • John_Lorenz

Posted March 26, 2005 - 09:37 AM

#14

My 2000 had horrible front brakes and I mean horrible! They wouldn't even lock up on the mud...

I picked a Nissin MC off ebay that was a leftover from the Cannondale bikes, got a Ride Eng. SS line and some Motul 600 fluid. I couldn't believe how much better it was. I'm sure the fluid and SS line helped, but I believe the MC made the biggest difference.


brandon I as well, but what fixed mine was a oversize rotor the motul and some nice EBC pads :)

  • RCannon

Posted March 27, 2005 - 05:42 AM

#15

Markit, LOL. You dont really even need Honda parts to make it better. The Honda mastercylinder kit drops right in if you want. It helps any of the Nissin Yamaha M/c's. The problem is cost. New webay m/c;'s are cheaer than a rebuild kit.

  • flogger

Posted March 28, 2005 - 05:48 AM

#16

OK as far as the fluid, I have not changed it and have no idea what is there. Pads are new. But something just is not right besides it being a Yamaha mc. I also have a 99 Yz400 and the front brakes will throw me over the bars. I will try the tricks of trying to seat the pads (Never done it before but worth a try). Thanks for the suggestions.
Flog

  • cowboyona426

Posted March 28, 2005 - 12:23 PM

#17

Get a Honda front M/C and a Honda-style front brake line, it makes a WORLD of difference in the YZ-F brakes! I bought my CR style hose on Ebay for $10 and a CRF 450 front M/C for $60, so I did a complete front brake upgrade for not much more than the cost of just a hose! You may get lucky and be able to find a complete CR/CRF front brake system cheap on Ebay as well.

  • mark794

Posted March 29, 2005 - 11:19 AM

#18

Just a note on bleeding, if it still feels spongy after bleeding at the Caliper. Try bleeding at the MC first. It has worked well for me.

  • popper357

Posted March 29, 2005 - 11:26 AM

#19

How do you bleed the brakes anyway? Can you open the drain on the caliper and pump the brakes till there's no bubbles? I have a 98cr125 that has soft front brakes. Has newer pads so I'm wondering what to do to get them working better? I took the top off the MC and fluid was overflowing, it that too much?

  • popper357

Posted March 29, 2005 - 11:36 AM

#20

Nevermind, I just read up on this.





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