Today I’m looking at disassembling the front brake master cylinder on a Honda CX650ED Eurosport, part number 45500-MG0-611.
There’s two screws in the top of the reservoir plate:
…and a warning saying to use DOT3 on top. The cap part number is 45513-MA6-621:
While rusty, the screws shouldn’t be TOO hard to get out:
They’re flat 4×12 screws, part number 93600-040121G or later 93600-040120G. Underneath the cap is a rubber diaphragm:
It’s part number is 45520-MA5-671, or later 45520-MA5-672. This particular one was leaking, and after removing it in the evening and returning in the morning had swollen enough that there was no way it was fitting back in.
The reservoir cap has a little channel in it:
…and there’s a matching bump on the diaphragm:
Looking into the reservoir, cap removed:
This little silver piece is marked as a “protector” on the parts fiches – part number 45512-MA6-006:
It should be able to be moved fairly easily with a pick or similar tool:
Underneath you can see the return hole, the much smaller one at the bottom of this image:
On the rear side, we have the sight glass/viewing port:
This one is fairly crazed:
…as you could easily see from the outside:
