UK Car Repair: Car Brakes Suddenly Go To floor and when I step on brake car hesitates or stalls out, 1997 chrysler lhs, chrysler lhs

Question
QUESTION: I have a 1997 Chrysler LHS car that runs pretty good. Recently the car brakes suddenly went to the floor without any warning and when I brake it goes to the floor but at the same time the car starts to hesitate or stalls while brake is to the floor. I cannot afford to put it into the shop so i am looking at different things it could be. My car has a 3.5 liter engine and it is fuel injected and I have never had my car stall before nor have the brakes ever gone to the floor before either. All help is very much appreciated. I am a woman and I don't want to have to replace things my car does not need. Thanks so much!!

ANSWER: The problem is the master cylinder, it has bad internal seals causing the brakes to lose pressure and as the servo operates, the vacuum from the engine is escaping causing the stalling/bad idle

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QUESTION: I spoke to a mechanic last night on the phone and he mentioned it might be the booster but he also said to start with the smaller things. He might look at it but he has no ability to put my car on a machine. Is is possible that a master cylinder this would come up on a test machine? Any suggestions are very helpful as money spent on things on needed would be a waste :)   Thank You

Answer
Hello, no machine is needed, this is not an electronic problem.  As I previously said this is a hydraulic problem, this is the only reason the pedal could go to the floor.  As you are also losing vacuum -this makes the engine run rough or stall- it means the vacuum is leaking through into the brake cylinder.  I think you need only replace the master cylinder BUT, as everything is off, as long as it isn't too expensive, change the booster also.