Folks!

I’m in the process of evaluating whether to upgrade the 15/16” master cylinder with the 10” boost master from 280zx 1979.  I tried to bench bleed the master cylinder and observed the below behavior. 
notice, I didn’t mount the reservoirs on yet.

 

fill up the cups and it’s very slowly draw in the fluid into the bore and out the F and R outlets.  I tried to tap on the side to see any bubble coming out.  Very little.  I even try to pump the cylinder and seem like just air coming out.  
Fill up the cups and left overnight, the F seem to be able to drain completely.

do I need to mount the reservoirs to help with the gravity to pull in more fluid?

Looks used.  Are you trying to find out if it's good?  The larger bore will actually create less pressure.  It's bigger because the ZX's had rear discs.

It is used.  I bought the Tokico rebuild kit.  Apparently, a close examine the Tokico and the Nabco, the Nabco is a bout 1mm shorter on both piston.  I think the Tokico pistons block the holes.  That's why no fluid gotten into the bore.

ahh well, probably a remanufactured one probably a better route.

Edited August 29, 20222 yr by 240zadmire