hard brake pedal

[moparmade43]

Ok guys, this question is actually on a 67 newport custom, not my duster, but the principle is the same, so here goes.

I just converted my 67 newport custom to front disc brakes, using all factory original parts, and spindles off a 73 newport. Brakes bled fine, as I installed a disc master and power booster when I did the swap. Before it was power drums on front. Now, my pedal is hard as a rock and wont even depress enough to activate the brake lights. Is there a possibility that the new booster is junk. When the car is idling, I can hear air rushing down around the brake pedal inside the car. Everything bolted up nicely, didnt have to modify anything, and when I bled the brakes the pedal went all the way to the floor. However, now, like I said, whether the car is running or not, the pedal is rock hard. Also, I verified good vacuum to the booster and out of the check valve in the booster. I'm leaning towards bad/leaking brand new booster, but anyone else have any other possibilities? The booster is a dual diaphragm design, should I have went with single diaphragm, or does that not matter?

 

[redfastback]

single or dual doesn't affect a rock hard pedal, just more vacuum storage and less pedal effort. with the car off, pump the pedal to rid the booster of al vacuum, hold it and start the car. if the pedal drops slightly, its good. run the car, and then shut it off and then pull the line off the booster. it should rush in with air. it sounds like yours is no good.

 

[dustertogo]

The booster is bad.