brake pedal goes to the floor

Hello out there, I have an '83 300td wagon and I have lost braking, I replaced the master, bled the lines, & replaced calipers. Could a bad booster or vacuum pump give the symptom of pedal-to-the-floor? Everything I've read and know from past experience says no it should just be a "hard press". please help!!! thank you

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Body and Interior Specific Aid

Chassis Model Number

W123

pedal to the floor

I hate to suggest this, but did you bleed the master? Pedal to the floor means internal master failure. Bad master out of the box? It is rare, but possible.

A new (or rebuilt) master

A new (or rebuilt) master cylinder needs to be bench bled prior to installation. The unit should have been supplied with plastic threaded inserts that screw into the three ports and have a nipple for attaching a short section of vinyl tubing that is to be routed into the reservoir. The bleeding procedure on the bench is as follows: Install the old brake fluid reservoir (empty) on top of the master cylinder Clamp the master cylinder in a vise, using rubber or wood jaw inserts. Thread in the supplied plastic plugs with nipples and short lengths of plastic tubing attaqched and routed back into the reservoir Fill the reservoir with fresh DOT 4 brake fluid from a sealed container Press in the master cylinder pluger slowly and repeatedly with a piece of broomstick or a large Phillips screwdriver. The plastic lines must be sumberged in the brake fluid inside the reservoir. When no more air bubbles are visible, stop the bleeding procedure. Note: you can also bleed the master cylinder installed in the car by this method, using the brake pedal to work the cylinder piston. If the plastic threaded inserts are not supplied with the new master cylinder, you can use the old brake hoses for bleeding purposes. I think they will tread into the cylinder ports (make sure first as I have not tried it). And to answer your question: a failed power brake booster will only make braking more difficult by requiring greater force on the pedal to stop the car. It will not cause the pedal to sink to the floor.