I have a refinished Bruce Stone pedal cluster and new PMB master cyclinder. I want to know how the plunger (rod ) from the brake pedal to the MC gets adjusted before installation. Looks like there is considerable latitude here.

Think about it Jim .... the pistons have to fully return when the pedal is released. So, 1/8 to 1/4 turn on the screw away from contact should suffice. if you know the thread pitch, you could exactly figure the "play".

The actual measurement is 1 mm (0.04").

Jim,
The adjustment will be a little loose if you adjust it with the MC and pedals out of the car. The thickness of the firewall will increase the play by the thickness of the metal.
Bruce

Can the adjustment be made after the MC and pedal cluster are installed in the car; or, should I bolt them together on the bench and adjust ?

Having a difficult time visualizing...

Install and adjust on car

or

measure thickness of metal between the MC and assembly (otherwise known as the forward firewall). Add that to the length of the rod if adjustment is out of the car.

or

place a piece of metal the same thickness of the forward firewall between the assembly and MC. Adjust from there.


Actually, if the rod hasn't been tampered with, it has a very good chance of not needing to be adjusted.

OK, sounds good. Last question; can the rod be adjusted when both MC and pedal cluster are installed ?

jim, glad you asked these question, because as i just finished replacing my MC, i had not even considered the need to adjust or set the depth of travel etc of the rod on the pedal cluster. I have a rebuild cluster that i was thinking of putting in, but the old one seems fine, so i probably dont have to make and adjustment since i did not change it yet, but at some point i will. I guess i should not assume the last person that messed with it had it adjusted correctly, so that leads to the question, how do i know it is set right and pressing in the piston fully or properly?

Good question .

I would think that that is the only way. It does require body twisting and some foul language, maybe a mirror and a bright light. Wedge yourself under the steering wheel and do it! If my memory serves me, that is how I did it.

reach down and pull the pedal up. Should move just a smidge, am I right?

Yup . Moved about 1/4 inch and I can see the adjustment and lock nuts.