Everything seemed to be working fine, although it truck seemed a bit sluggish.... But it kept getting worse...Then I started to smelled something burning... and ALL 4 brakes were smoking, and the brake lights were stuck on.
ALL 4 SMOKING
Fluids not returning to M/C which means the piston is not returning all the way to open up the return.
A- it's got crud in it and needs to be rebuilt / replaced
B - you've got the brake pedal adjusted wrong.