Rear foot brake problems

[marsrace2]

help, I think the master for the rear brake has gone bad. It has been getting weaker and weaker the last few times he rode and now no rear brake at all. I cant even generate enough pressure by pumping up the pedal to push ths piston on the caliper out all the way. I am just wondering if there is anything else I should try before I puy a new master cylinder. Tried to bleed brakes and gluid just dribbles out with no pressure whatsoever.

[KLCRACING]

Have noticed alot of the master cylinders break at the 90 degree bend, maybe yours is just cracked. Good luck

[nordic quad]

We had a similar problem with our Apex last week,i also thougth that the master cyl was gone,changed the brake pads and tryed to bleed the brakes but the pedal was still soft,looked at it again and found that the inner pad was out of position put it back and bleed again, problem solved.
Make shure everything is clean and able to move as it should.

[marsrace2]

I have taken everything apart and still cant find the problem. I even compressed the piston on the caliper and held it all the way in with a c-clamp and still cant build any pressure when pumping the brake pedal. I am convinced it is the cylinder unless some other strange thing is going on.

[nordic quad]

I was able to push the caliper piston in with my hands,but was still able to pump it out again with the brake pedal,i think our brake was acting up over sitting still for to long,ohh well it was time to change the pads anyway.How did the rear caliper move compaired to the front brakes when still mounted on.

[yfz450ba]

Our Apex did the same thing, I tried a few different things, but replacing the caliper did the job

[marsrace2]

went through everything possible, ended up replacing the brake cylinder and it is fine now.

[nordic quad]

I guess i better get a spare one before my sons go the same way.
:rolleyes:

[r1rider98]

My daughters is just the opposite . I have to bleed the rear brake all the time cause it locks up. Don't know what the problem is.

[redonkulousruntsracing]

Ok, am I the only idiot who spent over 2 hours replacing rear brake pads. Out of the 2 caliper bolts, one is directly behind the roundhouse bolt. So I took off the rotor, and the big *** snap ring that holds the aluminum caliper stand in place then took that off so I could get to that bolt. Man was I mad. There has to be an easier way. If I wasn't in such a hurry, I would have swapped that bolt out that I couldn't get to , with a stud and nut instead so I could take the nut off and the caliper. The DRR dads at the race this weekend couldn't believe that it took me 2 hours to change brake pads, but it did. I also relocated the rear brake lever so my son would quit using it as a foot rest!