Hi Guy's i have searched high and low for a rebuild kit for the rear caliper as that is the only reason i could think of as to loss of pressure ,i have new reservoire ,new bleed nipple ,bled it with bleeding kit ,but after sitting for a month while getting bike ready the brake is non existant again ffs .

Any thoughts greatly appd 

Slarty 

But, is there ACTUALLY air in it?
Have you re-bled it and there's definitely air?

And how soon did the air come out? As in, did it come from the calliper end or the cylinder end?

On 3/3/2024 at 2:59 AM, Snakebite68 said:

But, is there ACTUALLY air in it?
Have you re-bled it and there's definitely air?

And how soon did the air come out? As in, did it come from the calliper end or the cylinder end?

hi there is no air in the system ,i now find that the rear piston is siezed i think ,even with new pads the foot pedal works but little or no affect ,i think caliper needs a rebuild

 

Aaah, yeah, that will do it lol.
Should be an easy job...

Your best bet for a refurb kit would be a Yamaha dealer, and just do it yourself.

If you have the original hydraulic lines, there's also a possibility that it has deteriorated and collapsed inside, but that's fairly unusual.

 

Of course, it's also possible the master cylinder has failed...