rear master cylinder actuation rod too short?

[occam22]

I have a 78 with rear disc with no mods to the frame in this area. There is a threaded rod that screws into the foot pedal linkage assembly. This rod goes into the bottom of the master cylinder when you depress the rear brake peddle. Mine doesnt appear to be long enough. Even with the rod adjusted all the way out so only a few threads remain... I have to depress the pedal extremely far to get it to actuate the master cylinder.

In addition to adjusting that rod out... is there some other place or means to adjust the pedal action? I tried removing the pedal from the knurled piece that goes through the frame to shift it a spline or two... that only raised where the pedal rests so it hits the foot peg.

There is almost 1/2 inch of movement before it actuates the master cylinder... that translates into a lot of movement at the pedal

...there appears to be a threaded bung under the linkage for a bolt... is there supposed to be some sort of stop to prevent the linkage from fully returning?

thanks

 

[jchrisk1]

Yes there should be a bolt with a locknut that adjusts your brake pivot. It should explain the procedure in your manual. I don't have a good pic, but you can see the bolt in the top right corner here.

 

[jayel]

your plunger in the master cylinder may not be coming all the way back like it's supposed to... DANGEROUS I'd disassemble the master cylinder for a good cleaning / rebuild

 

[occam22]

Thanks guys. There is no bolt in that hole and i dont have a manual.... but it sort of made sense that there would be a stop there.