rear brake issues

[YZ120]

we lost the rear brakes today while practicing.
tried bleeding the system,nothing no pedal at all,checked the pads still like new,adjusted the accuator rod still nothing.

help please, my son is itching to race on sunday and i cant figure it out.
i believe that it`s in the master cylinder.

thank you

[WMW-F4R]

Sometimes you need to remove the rear caliper from the bracket and hold it up above the master cylinder to get it to bleed out. Make sure you have a spacer between the pads when bleeding.

If the rear brakes just go out with no visual leak, it's usually a defective master cylinder, but try bleeding it first.

[tony400ex]

Originally posted by YZ120
we lost the rear brakes today while practicing.
tried bleeding the system,nothing no pedal at all,checked the pads still like new,adjusted the accuator rod still nothing.

help please, my son is itching to race on sunday and i cant figure it out.
i believe that it`s in the master cylinder.

thank you

i had that problem... open the bleeder 8mm bolt... i used a air compressor.. and a fitting used to put air in a football and i blew the air in slow and got the brake fluid to the rear caliper......... when it comes out stop the air hold the brake down and close the 8mm screw

[YZ120]

i tried all the tricks. nothing worked so i took the master cylinder apart and found out that the seals were torn.
i`m going to call the dealer to try and get it warrantied.
i`ll let ya know how it turns out.

[Rey Deleon]

Bleed the brake system at the master cylinder first (brake line) and work the air out of the system to that point. then go to the rear caliper and bleed the line from the nut that connects the braided brake line (nhot the bleeder valve) and this will give you pressure.

[tony400ex]

you dont bleed the line from the nut..... thats why they have a bleeder 8mm bolt...