Ray, I'm probably going to open a can of worms here, but in my experience, bench bleeding a master cylinder is good practice. All you do is <u>gently </u>snug the cylinder in a vise, and run two short lines directly from the ports into the top of the reservoir, making sure that the open ends of the lines are below the normal full level. (I have a set of hard lines with a short piece of clear tubing attached,just for this. With the clear tubing, you can see any bubbles.}Then, using the method of your choice, gently push the piston to its <u>fullest</u> travel, repeating until no bubbles appear in the reservoir. Then, just install they cylinder as normal, but leave the bench lines there until connecting the real lines.
There are two advantages in doing this first, in my estimation.
1)You can tilt the master to place the ports at the high side, where the air will be expelled, and,
2) You can push the piston to its full range of travel, as doing it in the car will only take it to the pedal stop, <u>not</u> the piston stop, ensuring that you are getting the majority of the air out of the cylinder.
I've had folks tell me that bench bleeding is a bunch of hogwash, and then later complain of mushy brakes, whereas I do it my way, and still have a hard pedal after 45 minutes of racing.
Jeff