Oldsmobile/Buick Repair: Buick Century limited 1980, vacuum hose, cylinder problem

Question
My neice bought this car and the brake pedal goes right to the floor some of the time, other times it is hard like it is supposed to be, she replaced the front pads (did nothing to the back)and bleed them and it still does the same, sometimes it is hard and other times it will go right to the floor instantly, could this be a master cylinder problem or brake booster, or anything else, there seems to be no leaks in the system.

Answer
Sounds more like fluid is leaking past the seals in the master cylinder. Have it replaced by an experienced brake technician.

Usually when a brake booster fails you can hear air escaping at the brake pedal under the dash.

You can also test the booster by starting the engine for a minute or two and let the booster fill up with vacuum and then shut OFF the engine, wait 5 minutes and then disconnect the large vacuum hose from the booster in the engine compartment and you will hear a loud WHOOOSH sound. This sound usually indicates that the booster is OK.



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