Ive got an 89 F-350 and when i press the brake pedal it travels quite far and is somewhat spongy. ive bled all 4 wheels dozens of times and havent gotten any air out of the system, all 4 wheels will lock up (provided the rear drums are adjusted), there are no leaks, and the fluid is never low. im wondering if the master cylinder might have a bad o-ring? if so would it be easier to rebuild it or just replace it? thanx for any advice

 

make sure that the rear shoes are properly adjusted.
There is a RABS module bolted to the inside of the left side frame rail, about level with the drivers feet, that you will need to bleed. There is a bleed screw on it so bleed it just like a brake.

 

hey thanx ill try that, i honestly didnt know to look for anything like that.