I was getting a vacuum leak hiss under the dash, clearly related to brake pedal manipulation, so a power booster vacuum leak. I was afraid that it was a leaking diaphram, but it turned out that the a round seal that surrounds the white plastic pipe on the actuator shaft had popped loose. I could not push it on because the break pedal assembly mounting bracket restricted access. My dad took the braket off. I pushed the seal back into place and relubed the shaft. My dad reinstalled the brake pedal bracket. The hiss is gone, but now the break lights are continuously on because the break pedal arm is at least 1/4" away from the switch when the brakes are not applied.
The bracket appears to be located properly and seated completely.
The button is connected to the same bracket and does not seem to be adjustable. As far as we recall, we did not rotate the actuator rod, so we did not make it shorter (if it is even adjustable in length).
Any ideas what we did wrong?