AH HA!!
LITTLE TEST: With my sister's help I had an idea for a new test to see if the push rod clearance is good. I had her watch the brake fluid reservoir with the top OFF of it. Brake fluid at max line. Use a flashlight. I went in the car and gently gently gently with both hands for "control of the push" pushed the brake pedal down slowly slowly slowly .... merrily merrily merrily life is but a dream.. oopps i trailed off sorry.... I noticed an initial bump when pushing the pedal accounting for brake pedal play and then noticed a second bump as if the push rod was engaging late.
From the moment I pushed the pedal to the moment of the 2nd bump the brake fluid reservoir level did not move up or down AT ALL! What's this mean? It means that the push-rod to master cylinder clearance is WAAAAAY off in terms. From the pedal to the brake pads should be like the same type of response you get from a limb on your body. This space between the rod and the MC (about 3/8") accounts for not only not being able to use all the power in your brakes, but for late braking (milliseconds to seconds which count a great deal on the road) and for YOU GUESSED IT ... DRAGGING BRAKE PADS!
Check it out:
Don't have time tonight, but tomorrow the first thing I'll be doing is popping the MC off and adjusting that clearance. I bet you this nabs the damn brake demons and that I ended up ordering that Prop valve for nothing!
The specified space shown on the graphic accounts for what can be described in English as maybe the width of a sharpened pencil tip. This is damn near touching the MC back plate which is how it should be.
For adjustment, it would seem that you should get the push-rod out enough to where it touches the MC back plate lifting it barely off the booster mounting surface and then successively back the rod off in 1/4 turns till you have it right.
This also explains why I had thought that my 1st stock booster was bad and why the 2nd used OEM booster did the same exact thing cause this means my original booster push-rod and the 2nd used less mileage booster I bought were BOTH incorrectly adjusted too far back. Unfortunately and GOOD to know at the same time this may mean that all NA booster push rod's over time back themselves off from extended usage. This should be checked by everyone at least with an NA car.
I'm soooo excited.... and I just can't hide it.... I know I know I know I know....I want brakes... I want brakes ! YEAH! cheese cheese cheese... lol