Anyone have ideas on what's going on here?

I am restoring a '69 Charger. Just replaced the brake power booster. Adjusted the shoes. Bled the system - new fluid throughout. However...

The pedal doesn't move very much when depressed, and the brakes grab like a S.O.B.

So - I adjusted the pushrod that runs from the booster to the master cylinder (made it shorter)

The pedal will move slightly further now...but there is no "gradual" application of the brakes. As I depress the brake pedal - it does nothing, then WHAM!!! The brakes grab.

Any ideas?

'69 Dodge Charger
Power brakes drum all the way around.

 

Did you get a stock booster or an aftermarket booster?

I had that problem with my 71 Challenger. The aftermarket booster was too strong. Meaning the dynamics of the booster with the vacuum from the engine made them grab like that.

I sold the car (regret that) before I could figure out what to do.

That booster might be your problem.

Let us know what you find.

Mopar_71

 

It is an after-market booster from Checker/O'Reilly. It's what was called for in the parts book.

 

I assume you have drums all around you didnt mention any rotors. I would check the drums for contamination like rust and/or being warped. Machine your drums or replace I bet that would help if not cure your problem.

 

perhaps someone put a di non power brake master cylinder on? my dads power brake master went bad on his challenger so he put a non power master on so he could move it around. when you just touched the brakes it locked up quick.