Cadillac: stucked brake pedal, vacuum line, vacuum leak

Question
1991 el doraedo biarritz-after engine stopped in the middle of the road, tried to restart while stepping on the brake pedal, managed to run but when I needed to use the brake it got stucked-brake pedal won't go down when I stepped on it.

Answer
Sounds like the BRAKE BOOSTER has failed.

Start the engine and stick your head under the dash as far as you can get in back of the brake pedal. If you can hear a hissing sound, Like a vacuum leak, This would most likely be a ruptured diaphram in the brake booster which is the large round black device mounted on the firewall in back of the master cylinder in the engine compartment.

You can also disconnect the big rubber vacuum line from the brake booster and put your thumb over the vacuum line and see if the engine runs smoother.

If you can hear the hissing noise per above and or the engine runs smoother putting your thumb over the big vacuum hose, Replace the brake booster.


tom