400ex Brake problem

[QuadRacer18]

Is there a rebuild kit made for 400ex rear calipers? I have a BAD leaking problem and cant get any pressure in my brakes, ive tried to replace the smalll o-ring that goes on the piston and Ive had no sucess. Please help!

[JOEX]

Originally posted by QuadRacer18
Is there a rebuild kit made for 400ex rear calipers? I have a BAD leaking problem and cant get any pressure in my brakes, ive tried to replace the smalll o-ring that goes on the piston and Ive had no sucess. Please help!
Where is it leaking from?

There are three o-rings on the piston. Well actually there is a 'dust seal' and a 'piston seal' that are on the larger part of the piston and a small o-ring on the shaft. The two seals are what is in the 'rebuild kit', the o-ring is purchased seperately.

There are diameter specs in the repair manual for the piston and bore, one or both of those could be worn if replacing the seals doesn't help.

[QuadRacer18]

hmm, i dont remember seeing any seals that go on the actual piston... have any pics of this? would be helpful

[JOEX]

They are inside the caliper, not actually on the piston. Sorry for the confusion.

#2 in the diagram