My wife dumped her bike on the front brake lever while riding and now her brake doesnt work. Is it possible to smash the front brake lever so fast and hard all the way to the grips that the piston inside the master cylinder gives out? If this is the case, do I have to replace the whole master cylinder or can you buy a rebuild kit?
You can buy a rebuild kit ,but 1st push the piston all the way in by spreading the pads apart with a screwdriver-then pump the lever and see if the pressure comes back.
I have tried that and the pads will slowly close in on the rotor but you can still mash the brake lever to the grips with no resistance. I also tried bleeding the brake but that wasn't it.