This is an example of a front master cylinder, on a bike , in which the owner never changed the Brake fluid. Extreme and shocking I know. But it will happen, sooner or later to yours, if you don't change it when your supposed to. Sooner rather then later if you store your bike outside. No,it is not an RE master cylinder. I will happen to any bike that uses Dot 3 or 4 Brake fluid.
Believe it or not the brake worked! But can you imagine what could happen on the highway if some of those solids were to come loose and get into an orifice or two?
I can't wait to take apart the caliper
There is nothing wrong with Dot 3 or 4 fluid, but it must be changed! It absorbs moisture and eventually turns into a solid ! What fluid was left, was like a very loose Mud. Dot 5 is OK, but you will have to change it more often, because it does not absorb moisture. You'll get pockets of water in the fluid, not good either.
Just a heads up guy's, so you know why they tell you to change those fluids.