The Stovebolt Site Forums The Shop Area General Truck Talk Yet another brake pedal travel question

I hear you guys on the need to have the cab in place to do the final adjustments. I totally get that. The shop assembly manual illustrates the method for adjusting the brake pedal to achieve a 13/16" gap between the lever and the toeboard. The brake lever spring is constantly trying to force the lever into the cab, so the only way that adjusting the length of the rod at the master cylinder can be effective is that the rod must be anchored to the master cylinder somehow. I've noticed that images of replacement master cylinders (same style as the OEM cylinders) usually come with the rod sticking out of the rubber boot. Is this rod actually attached to the end of the piston?

As it sits in the photo I posted, if I move the brake pedal lever forward until the brake rod touches the face of the piston at the master cylinder, the lever will be even with the clutch pedal lever. At that point there is no lost motion in the linkage. This just happens to be how I have the rod length adjusted for now.

Thinking about how the brake pedal operates, in my mind the only thing that is going to stop the brake lever travelling towards the cab will be the arm on the brake light switch. If that is the case, it won't be long before it's beat to death. Or at the least it will beat its way into the toeboard.

In my case, I'm using a 1960s Corvette master cylinder (from NAPA) as recommended by the upgrade kit manufacturer. It did not come with the rod. The master cylinder upgrade kit came with the rod which has a round end that contacts the piston.

To help illustrate what I'm working with, I've cropped a catalog cut showing a master cylinder set up similar to mine. It clearly shows the rod with the round end that butts up against the piston. There is nothing to hold it in place, therefore the brake pedal spring pulls it away from the master cylinder as far as the lever will travel. So what's the secret to keeping the pedal lever from always wanting to go through the toeboard?