View Full Version : 76 Bonneville Master cylinder

01-07-2011, 2:33 PM
hey guys , im trying to remove a rear master cylinder from a 76 bonneville , the adjuster nut for the rear brake pedal is on the inside of the frame and the oil tank is in the way , anybody take one of these off before?

01-18-2011, 1:13 PM
You need to pull the entire assembly out including the plate that it is mounted on, remove the brake pedal and undo the big sleeve nut behind it as well as any other hardware that mounts the plate that the master cylinder is mounted to, as well as taking out the rear wheel. This is about the most sorrowful excuse of a master cylinder mounting assembly that I have ever seen!!

01-19-2011, 10:12 PM
what I do is remove the wheel, then unbolt the master cylinder and remove it, then crack the adjustment nuts loose and the rod will come out. the return spring can be re-positioned after it's all back together.
unless you are powder coating the frame I try not to ever remove the pedal assembly and the pedal mounting nuts they are a pain in the ass to get them to thread back together again with the return spring and all on it.
adjusting the free play and pedal throw is the fun part.

01-21-2011, 9:02 AM
I have probably 30 of these through the years and the simplest way is to take the brake pedal off and undo the big nut. I doubt that there is any other way. Worst part tends to be getting the footpeg off and back on as there is so much crap in the way, it is hard to bet a wrench on the bolt/nut head

01-27-2011, 9:40 PM
take pictures or make sketches before you rip it apart. It's a fact that this is the most retarded motorcycle rear brake set up known to man. loop some thin rope around the brake pedal spring to pull it back into place when you slap it all back together. also, good to change both the short lower brake hose and the long upper one between the cylinder and reservoir. the top one can bulge/stretch when it gets old and make the brake spongy. the lower one can still look OK, but gum up inside causing restricted flow brake drag. if the master cylinder is too cheesed up to rebuild, get a new one from Mitch Klemf in MN - great quality parts & prices and he'll share some tech advice if he has a few minutes to spare. a fresh disc ain't a bad idea either. I did all this on my 76 Bonni 2 years and 2400 miles ago when I did a retro restoration on it. brakes are fine. Good luck, man.