72 brake pedal soft and brakes grab- no feathering

[RustyPile]

Originally Posted by 71CHEVYSHORTBED402

Good advice from Rusty, but if that fails, I don't know, my experience with a bad Master Cyl. is the pedal is soft and the brakes barely grab. What happens when a booster fails?

Let's differentiate between "grab" and "apply".. "Apply" is defined as the friction surface (shoe or pad) coming into normal contact with the drum/rotor.. "Grab" is when the brake pedal is applied normally, but the friction surface locks onto the drum/rotor, causing the wheel/tire to slide..

With booster failure, what usually happens is the pedal gets extremely hard to push, EXTREMELY HARD, but no grabbing at the wheels. I've seen a few booster failures that take both feet to get the brakes to slow the vehicle.

The following is for the OP.. When you say "soft pedal", do you mean a low pedal before brakes start to apply?? If so, I'd look at brake shoes out of adjustment or severely worn so much that the wheel cylinder pistons are at the end of their travel and fluid is leaking past them.. As I stated in my original post, remove and inspect...