Topic: CB500K2 Master Cylinder Question

[Bear Four]

The circlip pliers finally arrived and made short work of disassembling the master cylinder piston assembly. 

Now I'm ready to re-assemble master cylinder, I notice that of the two holes on the bottom of the fluid reservoir, one is a through-hole about 1/8th inch. The other starts at the same diameter but ends in a tiny hole, like a carb jet.  Is this the way it's supposed to be or a manufacturing defect?  Just looks weird to me. I recall from 40 years ago that the front brake was not very responsive.  Comments?

[bamacb]

That's how it's made. One is supply one is return

[Bodi]

The bigger hole draws fluid from the reservoir to the piston. The small one lets it leak back up when the lever is released, so the caliper piston can push back from tight. If you just have a few mm of fluid in the reservoir, it will spurt up from the small hole in the first bit of lever travel... so be careful as brake fluid is amazing paint stripper.
Make sure the tiny hole is clear or your brake will not work right, it can drag quite badly if that is plugged. A strand of wire can be used to clean it out.