rear brake problem

[interceptorz28]

I have this 03 400ex that is new to me and I got it with the rear brake not working.

I am trying to determine if it is the caliper or the master cyclinder that needs replacing/rebuilding.

I have not been able to move the piston. The fluid is getting to the caliper and its not moving the piston. When I push the brake pedal, it goes all the way down, its like not building pressure. I loosened the master cyclinder nut and fluid does come out when I press the pedal.

I tried bleeding it and am able to, but the piston does not move. I c-clamped the piston because it was out a bit and get nothing. It seems frozen.

Any advice is greatly appreciated.

[JOEX]

Originally posted by interceptorz28
I have this 03 400ex that is new to me and I got it with the rear brake not working.

I am trying to determine if it is the caliper or the master cyclinder that needs replacing/rebuilding.

I have not been able to move the piston. The fluid is getting to the caliper and its not moving the piston. When I push the brake pedal, it goes all the way down, its like not building pressure. I loosened the master cyclinder nut and fluid does come out when I press the pedal.

I tried bleeding it and am able to, but the piston does not move. I c-clamped the piston because it was out a bit and get nothing. It seems frozen.

Any advice is greatly appreciated.
I'd take the caliper apart and at least clean and inspect it. If that doesn't help and there's no leakage i'd rebuild the master cylinder. A set of 90* snap ring pliers come in handy for that;)

[interceptorz28]

Also, the piston is white, not metal. It looks much different from a brand new piston.

Between rebuild kits and the time to do it, I think I will pick up a caliper on Ebay.

[j beatty400ex]

yo interceptorz28 if i where u i would try to figure out the problem first before u go out and buy something because thats the mistake i made with my 400ex. my rear brakes wernt working so i got new pads had them on for a week and then they got chewed off so i bought a rotor and pads put them on them i noticed brake fluid leaking out by the parking brake. anyway i got my rotor and pads on ordered up a parking brake block off plate.. the brakes worked for another week and the same thing happened. turns out my axle carrier, and bearrings where shot. i spent alot more money than i had to. so look into yours

[interceptorz28]

Yeah, I am doin my best to try and figure it out.
I got this 400ex and the kid I got it from did not take care of it. But that made for a killer deal.

It came with no rear pads and it was missing the 2 bolts and that little rectangular plate that holds the pads on. Well, Honda dealers get 10 bucks for each bolt.

I am confused about the way the piston looks. It is white, maybe the metal circle that covers the piston fell off or something..... I dont know??

[400exrider707]

post a pic of it.

[j beatty400ex]

you probably deffinitly lost the metal cap that goes on the piston thats the reason why the piston looks white . if the quad came with no pads and the rectanglular piece that holds the pads in place, than there would not be anything to hold the metal piston cap on. and if the kid didnt take care of this quad probably got dirt in the caliper some how and seized the piston up. so you might want to get a caliper rebuild kit u can find one on www.planethondaracing.com they have oem, and aftermarket parts there. or if u can can find a desent caliper off ebay, but if i were u i'd get the rebuild kit and either do it my self or have my mechanic do it, thats my opinion.