Nissin Calipers Overhaul.
The Bandit has been a lot of fun so far, but one thing was niggling me. Although all the discs and pads looked quite new, the rear brake was squealing so loudly I was actively trying to avoid using it.
So a couple of weeks ago I thought I'd whip off the rear caliper, clean up the pistons and pads, and apply some grease to the backs of the pads. During the cleaning of the pistons, I noticed part of an O-ring sticking out on one side. The only thing I could do was unbolt the two sides of the caliper and remove the pistons to see what was going on.
The secondary O-ring (dust seal) must have been so dry at some point that it got caught on the piston and worked its way out. However it happened, I popped out the pistons, cleaned everything up in soapy water, blew it all dry and refitted the O-ring along with rubber grease. With careful refitting of the piston, all was well. Obviously this was done with both sides of the caliper, and then new brake fluid was flushed through. The back brake was then perfect... and silent.
What I did notice while the caliper was apart was the amount of orange, jellied brake fluid hiding within. There is no way this stuff is getting out unless you strip the caliper completely, which left me wondering about the fronts...