YZ brake issues

[pvillesummit]

I have tried everything i can think of to get the brake to work on my TS with no luck. The caliper i am using is from my original kit from back in 2011 and it has always been a bear to get to work and never really has on my WR and now trying it again on a YZ450F. It did work great with the original Wilwood master cylinder but after i broke the lever i have been trying to get it to work with the stock master cylinder. It was on my Husaberg recently and only partially worked, never really got hard but would stop the bike but with the YZ, pretty much nothing. Is it possible that the yamaha master cylinder just does not move enough oil in the pull to make the Wilwood caliper squeeze hard enough? I did get a new 2016 kit and the caliper on that one with my Husaberg works great so maybe i just have a bad caliper? Any ideas?

 

[MotoTrax LLC]

I have tried everything i can think of to get the brake to work on my TS with no luck. The caliper i am using is from my original kit from back in 2011 and it has always been a bear to get to work and never really has on my WR and now trying it again on a YZ450F. It did work great with the original Wilwood master cylinder but after i broke the lever i have been trying to get it to work with the stock master cylinder. It was on my Husaberg recently and only partially worked, never really got hard but would stop the bike but with the YZ, pretty much nothing. Is it possible that the yamaha master cylinder just does not move enough oil in the pull to make the Wilwood caliper squeeze hard enough? I did get a new 2016 kit and the caliper on that one with my Husaberg works great so maybe i just have a bad caliper? Any ideas?

We have found that the master cylinder on our YZ isn't quite strong enough when using the hand break. The foot break cylinder has enough, but there is a size difference between them and as a lot of snow bikers know, it's hard to access the food break unless you only do trail riding. We started testing a caliper with a smaller piston so that it would need less fluid to push on the break. It has been working well so far. It has plenty of stopping power, even when slightly frozen.

There is a little difference in the calipers we use and the ones on your Timbersled, but there is enough similarity that I would imagine that it is reasonable to say the there is just is not enough pull on the YZ hand break. If you can find a new caliper that fits your TS with a smaller piston it would probably help.

Anyone else have this problem and a possible remedy?

 

[CATSLEDMAN1]

YZ breaks

last week I removed an over sized roadbike matercylinder that I had run for several years on my Yamaha, at the time it was and experiment to see if a big master cyl was the answer to good brakes.
I had all the same issues bleeding out the big Kawasaki master.

I put the stock YZ back on the bike. Seemed like it was never going to bleed so:

filled the line from the top
hooked the banjo fitting to the master cyl and pumped and watch air bubbles rise

then unbolted the caliper and slid a piece of flat stock same thickness as the rotor in between the pucks and bled the line just like a car, two or three squeezes..........pretty firm, re install caliper.

rode yesterday and played with brake and dragging the brake until lot, stopped and bled line again. pretty good..........as good as any of my snow bikes have been.



the reason for the caliper removal is many of the kit brake calipers are not perfectly aligned with the disc and they are bolted solid, not floating like the bikes, the uneven alignment often just results in caliper and rotor flexing when you are trying to bleed and you never get the line full of fluid before you pull the lever.

When you get your brakes pretty fair, check for flex in the caliper and rotor..................squeeze brake handle with your hand on rotor and caliper, if its flexing back and forth you will never really have good brakes. I have found floating the caliper will solve this issue.
WR and YZ, both use stock yam master cyl, two different Wilwood calipers, they work.

 

[pvillesummit]

Thanks for the info. I backed off for a while yesterday just to relax and then last night tackled the problem again. I followed all the directions to a tee by pumping fluid from the bottom up and got a little resistance on the lever. Played around with bleeding it for a bit then just put a rubber band on the lever over night. Not really much better this morning. I will try the removal of the caliper trick as i can clearly see that the pistons are basically moving the rotor the last little bit. I vaguely remember a few years ago that Allan at TS told me to look at the alignment of the caliper when it is on the frame and install shims between the caliper and the frame to take up any gaps of misalignment. As of now, i do not see any but i will take another look. My new kit had 2 shims on one bolt and 1 on the other so the misalignment of the caliper to the rotor must be a real deal.