Chris in Dorset England
CB750 Addict
Having reached the stage in my rebuild of fitting the front brakes I ran into problems bleeding the air out. Rebuilt calipers, new pads and new braided brake lines. Following the manual(s) resulted in a very soft brake lever, several attempts at bleeding produced no improvement, the lever almost reaching the grip. Not good. Time for a rethink. Clearly there was still air in the system, how to get it out? Then I remembered that there was an Allen headed bolt on the underside of the calipers with a small hole connecting the twin bores together. This bolt is not mentioned in any of the manuals, which is less than useful. I took the calipers off, one at a time, used a piece of wood between the pads to stop the pistons coming out. Lifted the caliper as high as the line would allow with the bolt uppermost. Cracked off the bolt 1/2 turn and gently squeezed the brake lever, result, lots of air bubbled out! Closed the bolt, released the lever, and repeated. Refit caliper. This on the other caliper as well. Result, a good solid brake lever. I can only assume the Allen bolt is a secondary bleed point. None of this is mentioned anywhere in the manuals. Hope this helps someone with the same problem.