Question about installing master cylinder on 68 dart
FYI..
The bellows would be normally attached to a metal retainer.
There is also a plastic one for master cylinders that have an internal snap ring to keep the piston in the bore.
The round ring with the hole in the center is the keeper for the push rod. I believe it is supposed to go into the piston before the push rod goes in, but I'm not 100 % sure about that.
If you don't use the bellows leave the keeper on the MC the way it came, but I think it is only intended to be a shipping part.
If that keeper comes loose and rotated, the piston could come out and you would have brake fluid all over your floor and you would loose your brakes.
Watch this and decide if you want to do it right or not.