Rebuilding the hydraulic piston on the front brake.

[Revvy Kevvy]

After new year I have some choices about rebuilding the front hand brake, I have bought a hone and a new set of piston seals (a couple different varieties) and I have bought two whole new hand brake assemblies.

I would like to keep the bike as original as I can so my first push is to hone out the cylinder using the tool in the picture. Its a 14mm hone for small bore pistons and I am wondering if anybody has ever used one. I have used hones before and its typically running it up and down (I think with light oil from memory) making cross hatch patterns on the cylinder walls until the bore is smooth. Has anybody else ever used a hone like this one and how did it go? did you use any light oil or just dry? Previously I have used hones on like a spring (looked like a engine governor) so this is a very new idea for me with hones. It looks like a bunch of balls so I am not too sure how it works.

If it fails I have bought the two brand new hand brakes so I will just fit one of those but keeping it as original as possible would be nice.

I also have a complete rebuild kit comming from yankee land as well as a set of front disk pads disk pads

 

[Revvy Kevvy]

Ok, here is how this ended. Since I dont like to leave threads open.

The 14mm hone seems to work really well. I used it dry and it cleaned up the cylinder quite well after 25 years of being abandoned.

I ended up using the yankee piston rebuild kit but as far as I could see the others would have worked just as well. They was same length and same size. Now the handle moved nicely although I still have to put hydraulic oil in the system (brake fluid DOT3) I need to put my wheel back on for this and before I put the wheel back on I need to rebuild the front forks.

I am kinda confused by a large Oring(seal) that came in the yankee kit as its nowhere in the piston assy and nowhere in the brake assy that I can ascertain. Have a look at the picture for me called Oring or Oring ans assy and does anybody recognise it? Where does it go and why is it included in the rebuild kit?

If they wonna include extra bits a new handbrake leaver rubber cover would have been nice.

If no leaks when I put the brake piston assy on and test then this job is done!!