The cause of hard brake pedal is malfunctioning brake booster. Check the hose from the intake manifold going to the brake booster for cracks or leakage, replace if necessary. Check the one way valve located in the middle of that hose, make sure the valve opens when you put pressure on one port.. If all those mentioned are ok, the booster itself needs to be replaced....
Shifter is blocked by a device attached to the brake pedal. If the brake pedal is not depressed it wont allow you to change out of park. There should also be a bypass button next to the shifter, in case the cable to the pedal breaks.
The brake pedal has nothing to do with it. If air is in the system then bleed the brakes.
brake switch located on the top of the brake pedal
Hardness in the brake pedal can because by low brake fluid. Air in the brake lines can also cause the pedal to push hard.
Check around brake pedal for something rubbing. If OK, I'd look into the master cylinder.
You need to bleed the brakes. Loosen the bleeder valve on one of the calipers and have someone press and hold the brake pedal. Tighten the valve and release the brake pedal. (If you let off of the pedal with the valve loose, air will be drawn into the system and make the problem worse.)
Check the switch adjustment on the brake pedal arm.
Below steering column on console panel, above brake pedal
Check the brake light switch it should be connected to the brake pedal somewhere.
out of brake fluid?
It causes pulsation or shudder on the brake pedals.
The brake pedal and the accelerator pedal can cause a change in speed.