67 Brake Pedal SQUISHY!!! Help!!!

FIA-ERA · Oct 15, 2009

Hey guys, just got all the brakes back on and took it out for the first test drive. Everything is all new or rebuilt. The pedal has about 1 1/2" to 2" of just "dead pedal" before it even wants to begin to stop. Its lighter than the gas pedal! It is a VERY weak to me but I haven't driven too many old Mustangs with a booster on it. The brakes stop fine once it gets there but the pedal is a little dis-concerning if you will! I will do so more investigating BUT what is the experiences here? What is "normal" for a 42 year old car? Everything I've ever experienced (66 Mustang Fastback with 4 wheel disc/ manual brakes) compared too, this is a little uncomfortable. My fastback will give you 9 cents back on a dime!

I replaced the booster with a rebuilt one from cardone (midland unit) complete with master already on. I will check for vacuum as it almost feels like it doesn't have enough "pressure" behind the pedal. The pedal is as high as it will go and the push rod was the same length as the original. ANY HELP is greatly appreciated! After this is the carbs! I drove for 15 minutes and just about passed from the fumes, a little rich! Thanks, Matt

2+2GT · Oct 25, 2009

Was the headspace adjusted when the MC was installed? Are the calipers on the correct sides? Easy to get wrong…

67200F5A02206 · Oct 28, 2009

Check the adjustment of the rear brake shoes. If they are not tight then you have to pump enough fluid to get them to engage before the pedal will firm up.

They should be dragging slightly as you turn the brake drum. After adjusting, step on the brakes to center them. They might need further adjustment.