How to bleed the Brake Master Cylinder?

[Rasteirinho]

Quote:The front piston in the MC sends fluid to the front brakes, did you check the piston positioning and set the piston stop bolt properly?

Are the rear brakes OK?

I think the MC pistons are correctly fitted and the bolt also. I have brake fluid in the calipers (front and rear).

The rear piston is contacting the pads but i will check if is the PKB that is doing that or the brake fluid.

I think i will remove the pistons from the callipers and see if it's stuck.

[Lipinhu]

Have you sanded the brakepads of the inner side? Mintex has that bit of extra work! You got to sand them, otherwise they stuck!

[Rasteirinho]

stock pads

[parrot]

Lipinhu Wrote:Have you sanded the brakepads of the inner side? Mintex has that bit of extra work! You got to sand them, otherwise they stuck!

I am about to put M1144's in mine. Can you be specific on whats required?
Sorry for this slight fall off topic.

[Lipinhu]

This is a picture of what I did, its out focus, but its helpful. I used a benchgrinder insted of a file, took like 20 seconds each pad. If you put a standard one over the mintex, you´ll easily see where to sand.

Pedro
Try without pads! just too see if it´s coming off!

[parrot]

That's great, thanks!

[Rasteirinho]

I suspect the problem is something wrong inside the BMC, maybe the front piston is damaged.

The rear brakes are fine, the front ones are already better but they are still not good.

Maybe the rubber from the front BMC piston is damaged and isn't sealing the fluid properly.

[parrot]

Possibly if you released the piston stop bolt allowing the piston to move back past the bolt, then put your foot on the brake pedal pushing the seal into the bolt once tightened up again, it may have damaged it.