Next to the splooge hole

[crazy steve]

I have reassembled the master cylinder and when I squeeze the lever the cylinder does not return as it should. It does eventually return but it is slow. Will this change once I put fluid into the system?

I did not lubricate the bore with anything before putting it back together, but it was still wet with brake fluid.

It should pop right back if you press the piston in, so if it's coming back slow it's because of the lack of lube or there's still some crud in/on the m/s bore. Try pouring a bit of fluid in in it, and if that doesn't help, you'll need to hone. This will damage the seals if you don't address it. A light honing will clean this up.

To hone it, pick up a piece of 3/8" wood dowling. Cut it about 6" long, then hacksaw a 2" long 'split' in it. Fold some 600 grit sandpaper and slip it in the 'split' you cut. Wrap the paper around the dowl so it'll go in the cylinder (you don't need a tight fit) then spin it with a drillmotor. Hone/clean the bore just until the piston moves easily. Once it moves freely, thoroughly clean everything and reassemble.