I just put new guts in my rear master cylinder (1990 Cr500). New guts only lasted a few rides. The upper cup gave up. I know I need to check for pits etc in the cylinder but I also wanted to make sure I had the cups installed properly. Does anyone know which way the cups face? open side up or down? Upper and lower cups same?
Thanks, that's the cleanest schematic I've come across. The problem is that it is still difficult to tell from the picture which way the cups are facing, up or down.