it would help a great deal to know the year of the truck and the equipment and if it two or four wheel drive?
but a general detailed inspection of all four wheels, brakes and flushing the old brake fluid will usually find the cause, if its a later model pull the trouble codes and get a shop manualcheck the fuse for the brake lights, the fuse for the ABS and check your abs sensor on the top of your rear end is not either unplugged or shorted.
these guys might helphttp://www.fordbrakes.com/board/index.p ... &board=2.0http://www.ford-trucks.com/forums/43057 ... ost3945409http://www.ford-trucks.com/forums/29507 ... ke+failurehttp://www.ford-trucks.com/forums/27111 ... rakes.html
theres a great deal of useful info in these threadsviewtopic.php?f=63&t=526viewtopic.php?f=63&t=1848
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!