I use my cruise control every day. Today it doesn't work. My Brake Idiot light came on. This is the 2nd time the brake light has come on and I find the fluid down by 90% in the last 2 months. No fluid on any surfaces in engine compartment or wheel areas. Recall completed in 2005 for Cruise control.
Any suggestions?

 

Check your brake linings they may be worn way down...otherwise there has to be a leak, it is a closed system so it has to be going somewhere. be sure to check on the inside of your tires if you don't see it there maybe it is an internal leak in your master cylinder...(I don't know if that is possible on an F150 but I have seen it on other vehicles)
Is your pedal spongy, or does is slowly leak down if you press hard and hold steady pressure?

 

2 months ago installed new rotors, calipers with mounts and shoes on front.
Brake pedal hard.

 

Then I would say that whomever did the job may not have bled the line out all the way and you had to work out some air of the lines. Top it off and see if it happens again, if you want bleed them again just to make sure.

Other than that buy a good quality anchor and get ready to throw it out the window if your brakes go completely...