Wednesday, December 7, 2011

Chopper Stopper

I finished up this gixxer master cylinder last night. I am waiting on a rebuild kit, then it is going on the evo. I cleaned up all the casting marks and rounded the corners and such. Then I bored it out to 1", and gave it a decent polish. It is sexy small.


  1. Ive got a couple questions on this topic if you don't mind.
    1. I assume the rebuilt is to accommodation the change in brake fluids, dot 5 not mixing well with others?
    2. Do you know the bore size and how does the lever feel compared to stock?
    3. Is the res tube any special material? I was thinking of using some sight gauge tubing from lowbrow.

  2. No problem. The rebuild was only necessary because the piston was completely frozen in the bore. It had a hard yellow crust built up all around it. I actually had to beat it with a hammer. I got the m/c off ebay and the seller didn't say anything about that. Honestly, it was a crapshoot even using the part after that. The mix of dot 3 (or 4) and the HD 5 is OK as long as all the parts are completely cleaned in denatured alcohol. I would have felt safe with just a good cleaning and flushing. The bore size on this is 5/8", which feels close to stock, but a little more firm (less lever pressure to apply the same amount of brake). I have the single caliper on my front end. Res tube was some special chem resistant stuff I had left over for fuel line, I got it in a 10ft roll from McMaster-Carr. It is super bendable. Since you are using Dot 5 silicone based stuff, it really is a lot more forgiving than the old "eat through your paint and skin" DOT 3" brake fluid. I just switched out the yellow stuff for some standard clear as it looked weird with the yellow tube and purple fluid. The Lowbrow tube will work great. Any more questions, don't hesitate to ask. I appreciate your interest and thanks for checking my spot out.

  3. Thanks for getting back to me with such detailed info. I've been having trouble finding definitive answers elsewhere. I'm on the QCB forum as well ( how I found this blog) and saw a post on this mod but figured hitting you up here would be a bit more direct. My QCB handle is Sewer_Rob. Thanks again.