I have a 86 f150 4x4 4.9l 4 sp, no brakes.
was driveing to get my son from school and pulled in to parking lot and pedel went right to floor no stopping i rolled about 30 feet till i was abel to hit e brake. what gives??? dont see any leaks removed the master cover fluid ok replace the cover strted truck pumped a few times have pedel???????about 1/2 down road no breaks??????????? any ideas.....got to house looked at all wheels no leaks checked master fluid good??????????????????help

 

Did you try bleeding them, might have a pocket of air in the hose. If you did you might have to get new rotors up front, you might of got the front disc shaved down to much.

 

Last time that happened to me it turned out to be the master cylinder deciding to retire while heading down a hill (strangely enough while I was carrying a bedload of parts to mod that particular truck!)

 

I 2nd the master cylinder diagnosis. Happened to me, 1 stoplight everything is fine, next light pedal goes to the floor with dash brake warning light on. Luckily I was only a couple of blocks from home and could use the parking brake to stop.

 

thanks guys it sure did make me have to clean my pants, it was the master cyl 15.00 at auto zone