Brake Problems.....On Atc200x

[1987atc200x]

I have a 1987 atc200x and am having rear brake trouble.....I have been riding all day and 3 times today my rear brake locked up and to get it to release I had to release the bleeder valve........then re-bleed it to ride......IT works but every hour or so of riding it gets locked up again....The brake works good when I use it but it locks up even when I dont even use my rear brake hardly any.....Like if i'm riding in my friends yard pulling wheelies.....I just dont know whats worng....anyone have any ideas.....Oh ya here are some pics of me wheelieing on my atc.....

[super90]

Rebuild the caliper. That would probably stop it. Are thoes older 200x fenders on there?

[1987atc200x]

im not sure......I got the bike for 100 dollars then I put a newer engine on it and sort of restored it to riding condition.....I dont know if it older fenders but it could be......Are you sure the caliper needs rebuilt becazuse it dont leak and it works all the time until it finallly locks up.....I sort of think its the master cylinder but not sure.....Oh by the way it just started doin this today......anyway thanks

[team-red-rider]

it may be a collapsed rear brake line...our car did that..we replaced the line and it worked fine afterwards

[riverrat]

If you have to release the bleeder valve to ride again, that is your clue as to what is wrong.

So pressure is going into the brake caliper, but not returning to the master cylinder, until you bleed it.

Which means you are depressing the master cylinder all the way, and probably freeing up what ever is blocking the return flow of brake fluid, until you ride a little, then the debris finds its way back into the return hole.

Taking apart the master cylinder is rather easy. There are two small holes in there, and you need yourself a piece of telephone wire, or my favorite, the wire from inside a twist tie, and snake those holes out. Clean the entire master cylinder, and flush the resevior. Do this over a bench, so you don't lose any small parts.

Check the ends of the brake line as well, for debris, and flush that out too. Probably been 20+ years since its been apart.

But that's just my guess ;)

[1987atc200x]

THanks I will try what you said when I go out to work on it....thanks

[1987atc200x]

Well thanks river ratt......Your advice helped alot....I took that piece off and it had a bunch of rusted, old, dirt, and crap all inside of the ports so I cleaned it out with some wire and a air compressor and it was done.....Works good as far as I can see because I rode it pretty hard for atleast 30 min. with no prob.....Even slammed the brakes a few times to see if it would jam up and it didnt. Plus I even let my buddy ride it and he usually pulls off breaking anything...lol....thanks again....