ATC 250r Rear Brake Locked Up

[Darius1502]

Hey Guys,

The rear brake on my 250r is locked up. Do you think its the caliper, or master cylinder? Or could it be both? What usually causes this?

[Red Rider]

Darius, I've never encountered this issue before, but if your parking brake is still installed, I would start there. It just seems like the cable actuated parking brake system would be a little more trouble-prone than the hydraulic brake system. Also, did this happen while riding, or after being stored for a while? Let us know what you find out.

[90guy]

I had this happen to my Mach z this past winter. I was able to pull the bleeds and it released but would lock right up again. I ended up bleeding a lot of fluid through the caliper and it finally came around and worked. So much garbage came out. Just an idea. I thought I was going to have to do some rebuilding and it was just something like that.

[shortline10]

The vent in the master cylinder might be clogged . If its hydro locked then that's probably the issue .

[Darius1502]

Thanks guys. I'll check all this. Def. the trike sits a lot. She's a survivor so I think it prob has the original fluid in there too.

[atc007]

Usually they are very tight,but will roll slightly. If the slider pins are dry/seized.

[wonderboy]

My guess is that your brake piston isn't retracting after stepping on the brake pedal. Your dust seals and piston seals are probably shot. Try pushing the piston back into the caliper and then stepping on the brake pedal and see if it locks up again. Probably just need a rebuild kit.