Brake fluid hydraulic lock
Posted: Sat Apr 04, 2015 8:10 am
Had an interesting issue on my 82 Honda CB500 custom. After riding for a few miles, the front brake was dragging very badly. I first suspected draggy pistons, but by loosening the bleeder fitting, the brakes released. This MC has been sitting for a few years so I suspected that there might be a problem with fluid returning to the master cylinder. With some guidance about the hydraulic system on this site, I discovered that when the brake handle is released, a small amount of fluid must flow back to the reservoir. So I disassembled the master cylinder and found that the small fluid return hole was totally plugged with crud. Cleaned it out, all is OK now. I saw several strings about sticking pistons but hadn't found on on hydraulic fluid lock. Maybe this could be helpful to someone.