There's a little black servo motor on the right side of the steering column (a little below the bottom of the dash) which releases a cable when you press on the brake. When you release the brake, the cable will get sucked back in (if it's working properly). Mine was burned out, so I disconnected the power to the motor, pulled the cable out and fastened it so it was always disengaged, and now I can always shift out of park (probably even if my foot is off the brake, but who cares unless you have kids who meddle with your car).
Check brake lights--if they do not work shift interlock will not release
the brake neutal switch is defective, the brake must be depressed before shifting.
If your Mercedes won't shift out of park, you might have an issue with the brake sensor or the brake itself. The brake must be fully depressed in order to shift from park to drive or reverse.
You did not have to apply the brake on a 91 model to shift it. There's nothing wrong.
Shift cable needs to be adjusted.
the button will not go in when foot is on brake
Yes there is. It is called a brake pedal interlock and the part number is 2609-4827
Make sure your brake lites work.If they dont replace brake lite switch
brake switch gone bad car will not shift out of park if brake goes bad
It releases automatically when you shift out of park. If you have to do it manually under the parking brake is a silver handle that releases it.
Many vehicles are equipped with a safety mechanism that requires you to press the brake pedal in order to shift out of park. Sometimes the release switch on the brake pedal wears or otherwise becomes out of adjustment, sometimes the switch fails and sometimes the release solenoid fails.
The switch on the brake pedal may not be working, if you unplug the wiring from it it should shift if this is the problem.