Rear brake S***s!

[bondo]

Cruiser, Thanks for the offer. i'll double check, but I think my '08 uses a Nissin system (I know the calipers and front brake mc are Nissin, will double check the rear master cylinder).

 

[PEB]

What Yamaha pedal did you use? How about a pic?

 

[bondo]

I used the pedal from an '08 YZ250. Had to also buy the pivot bolt, an o-ring or two and I bought the locknut (to save me the trouble of looking through my spare parts bin). Will see if I can get a pic up.

 

[moto9]

Your problem could be a worn out line, even if it look fine.
I have seen the same situation on a couple of other bikes where the line expands under pressure giving that mushy feel.
changed the line and that fixed the problem.
I replaced my pedel with one off of a KX 250.

 

[LAWMAN]

I went thru something like this when I 1st got my '07 300 (used). the pedal would go soft when the system got hot, but all looked fine. I bled it numerous times, changed the pads, lowered the pedal, etc. etc. I finally got tired of chasing it/ruining rides & just replaced the MC, SC & Hose--problem (whatever it was) solved. Probably could have fixed it with a rebuild of the SC & MC, but I ran out of time to jack around with it.

 

[bondo]

Here's a pic of the bike with the YZ brake pedal.

One nice thing about the Yamaha unit is that there is a hardened insert in the hole for the master cylinder plunger. I'm hoping this will prevent that hole from becoming elongated, as happened with the stock GG pedal.


(not sure why the pic shows up so small. It's about 8" @ 72 ppi on the long side. Try clicking on it to enlarge).

 

[blitz11]

Did this fix your problem?

Thanks for the picture.

 

[bondo]

Problem solved! Just replaced the semi-metallic brake pads with EBC "red"
pads. Roughed up the brake rotor with some emery paper (it had been polished to a mirror finish by the semi-metallics), and took it for a ride.


The rear brake now works as one would expect. Good feel, powerful, but not touchy, and will lock the back wheel on command.

Didn't even have to rebuild the m/c!

 

[gasgasman]

I used the pedal from an '08 YZ250. Had to also buy the pivot bolt, an o-ring or two and I bought the locknut (to save me the trouble of looking through my spare parts bin). Will see if I can get a pic up.

So, a Hammer Head, Sun Line etc YZ brake pedal should fit?

 

[stainlesscycle]

So, a Hammer Head, Sun Line etc YZ brake pedal should fit?

according to yamaha parts crossover yz125 and yz250 (2t) 06 and up are the same. it looks like on the pre 06 the length of the arm for the rear pivot pin changed. earlier may work also... yz250f, wr250f, yz450f, yz426f may work also. someone here have one they can check?

 

[Jakobi]

I have looked at the pedal on my 2004 WR250F and looked at the one on the gasser and had the light bulb come on in my minds eye. They sure look like they'd swap over and the Yamaha one sure looks alot stronger. I was too slack to start undoing them to see if they'd change though.

 

[stainlesscycle]

I have looked at the pedal on my 2004 WR250F and looked at the one on the gasser and had the light bulb come on in my minds eye. They sure look like they'd swap over and the Yamaha one sure looks alot stronger. I was too slack to start undoing them to see if they'd change though.

can you measure the distance from center of pivot to center of rear mount? that would tell us if it'll work...

 

[gasgasman]

I had a friend with a YZ450 break his brake pedal.
I carry a spare Gas Gas brake pedal and we tried it on his bike but it did not fit. It would hit the side cover when bolted down.

 

[Jakobi]

I'll measure it up for you. From inspection the GG brake sits tighter against the clutch cover than the yamaha so that would explain why the GG one may not have fit. I'll take some pics tomorrow and post back.