This weekend I swapped the brake/clutch pedal combination for the correct automatic brake pedal in my ’68 with power drums.

New pedal sets 7+” high off the floor (the brake pedal on the brake/clutch combo also set very high off the floor. I thought this was just that pedal set)
The auto pedal (sounds like something out of the Flintstones) is correct for the car and appears to be mounted correctly. The clevis pin is attached to the lower hole in the pedal as the upper hole is filled with stop light switch paddle. From what I’ve read this is correct.

The rod and clevis assembly (booster) appears similar to the picture on Pozzi Racing web site. So much so that it could be a picture of my booster. Mine measures about 5.5+” from the booster mounting hole to the clevis pin. And the clevis is adjusted to shorten the rod assembly as much as possible.
http://www.pozziracing.com/brakes.htm

Crown Point Joe was kind enough measure his pedal and reported an approximate height of 4.5” off the carpet. The shop manual specifies a minimum of 4.094”

I searched the tech section and found several relative topics but no solutions. From what I can tell, my booster is correct with the “short” master cylinder actuation pin. Master cylinder also appears correct.

I need to double check the pedal bumper but I believe it’s there.
Seems the only solution would be to shorten the booster rod but then the pedal would not retract to the bumper.

Any ideas as to why my brake pedal is so high?

When I replaced my original Master cylinder and added a booster, I had to shorten the threaded booster rod by about an inch or so.

Dont worry, it will sober up in a few hours :p
Sorry Dennis, I just couldnt help myself.

Probably brake fluid fumes...

That's It!!!
I didn't sniff enough brake fluid this weekend!

I prefer B-12 or laquer thinner.

The pedal bumper should be only for manual brakes (which may have an external return spring). With power brakes the pedal wont touch the bumper. Sounds like maybe the rod and/or clevis is too long. There were different lengths of both.

When I was reading, I thought it sounded about what the distance is on my pedal. Even so, I went downstairs and measured the distance.

The measurement on a 9 with manual drums is 6 9/16" off the carpet, so it would be a safe guess to say it's 7" off of the floor.

This is manual drums, it's on a 9, so there might be a difference. I instantly adapt to vehicles, so it's automatic when I jump from 4 wheel power discs to manual drums. The thing is it can seem as an odd way in which to step on brakes, going from pivoting the heel of the foot to doing a deep knee bend to apply brakes.

With manual brakes the pedal does need to be very high.
That's one of the reasons some people like power brakes so much. If done right, they can just pivot their foot instead of raising it, because much less pedal travel is needed.
For pedal height measurement on 1968 power applications, refer to TSB 68-1-47 (complaints of low brake pedal) under 'brakes'
http://firstgenfirebird.org/dtb/index.html

Sixstarved,

Thanks for the info.
I was under the impression the pedal should return to the stop. Since that is not the case the solution is simple. I'll thread the booster rod a little longer, cut off the excess and put the pedal where it should be.

Thanks everybody.