I have been driving my 1991 Ford F-150 5.0 4x4 single cab long bed for about 2 years now. about a week ago i was driving and normally pressed on the brake to slow down and it went down to the floor then i repumped and it stopped the truck. yesterday the brakes worked perfectly all day then this morning i get in my truck take off and slow down for the first stop sign and no brakes. so i parked the truck at home for rest of day, i replaced the brake pads tonight cause they were wore down with about 1/8" left. i took a test drive and the brake is almost hits the floor to stop the truck, what is the next thing to do? Thanks

 

Is the Master Cylinder reservoir full of brake fluid to the full mark?

Are you having to add brake fluid because of leaks?
(Check back-side of each tire for brake fluid residue from a leaking Wheel Cylinder)

If your answers are Yes & No and there are no leaks.

Replace the Master Cylinder.

 

I now have new brake pads and a new master cylinder, so far have not seen any leaks. but the brake is still softer than it use to be.

 

did you bleed the lines?

 

Hopefully you bench bled the master. Bleeding it on the truck isn't good enough.

 

Very important, because of the angle you cannot bleed the master on the truck as you will always have some air trapped in it.