my truck is a 1994 f150 2 wheel drie the inline 6 300 the brake pedal goes to the floor when pressed what should i check the master cylinder is full. thnaks alot for any help

 

If you've got no leaks at the rear wheel cylinders (remove drums to look or inspect backing plates) and no leaks up front, then most likely it's the master cylinder that needs to be replaced. Also have an assistant push the brake pedal while you look at the front and rear rubber brake hoses that go to each wheel (with safety goggles on) for ballooned hoses which can occur on older vehicles.