Master Cylinder Front Brake Rebuild - Other Brand kits?

[jdalton1]

The front brake on my 2011 EC250 two smoke is dragging. When I squeeze the front brake, the brakes will apply pressure to the rotor but won't completely release the pressure creating a drag after I release the lever. The brakes also sucked on my last ride, I lost all feel in the lever and squeezed as hard as I could to get 25% of the normal braking power I usually received. It sounds like either my master cylinder needs a rebuild kit or my brake line is preventing the fluid to flow back up after letting off the front brake. I would like to start with the master cylinder and was curious if the Nissin front brake was the same as Yamaha's or Honda's, if so which model and year? Are there any threads or pdf's with a list of other manufacturer parts that also fit the GasGas? Any other recommendations on my front brake issue? Thanks for your reply.

[Rick]

Sounds like you have a little air in the system. I'd try bleeding the system first.

[jdalton1]

We bled the brakes back at camp without improvement, I may need to try it one more time. Also I realized I should have posted this thread in the brakes sections, my fault. If anyone knows of other makes/models that use the same nissin brake caliper, that would be great. Thanks.

[cbutler]

My 03 MC250 and 02 EC200 are the same as my 05 Honda 450X.

I have had good luck with break issues in the past by using a zip-ty to hold the break tight to the bar overnight.

[(F5)]

If you have trouble with sticking on usually it is the lever is adjusted so the piston can't open the hole fully. There should be some freeplay.

Either way I'd start by pulling the calliper down for some routine maintenance, clean it out, carefully pull out the seals & inspect them. Usually they don't need replacement but crud does build up there & it can help to clean it out, would expect on an older bike than '11 but dirtbikes get a hard life.

Then new fluid, adjust lever correctly & bleed. You'd be unlucky to need new m/c seals, they last & last unless water gets in & settles.

Just did my calliper dust seals (kit came with dust & main seals), but its an 07, they were slightly twisted.

[zeuszuki]

I would be looking at the caliper first. Remove it from the fork, remove pads and inspect pistons , slowly pump the lever while holding one piston while other comes out ( don't rush it ), clean all crud off and repeat with other piston. Both pistons should be able to be pushed back into caliper body relatively easily and feel smooth when doing so. If not then caliper needs a strip down and full service. Bleed system up and enjoy :-)