The brakes on these trucks can make an average mechanic look like a fool. When one of these trucks come in everything needs to be checked. And when a customer observes a problem at one wheel, just because it looks OK up on the lift really needs to be checked carefully.
They trucks on the '05+ vehicles still have the handicap of sliding pins corroding and causing a dragging or locked brake. Those are easy to find and repair as long as you look at the pins.
But with the '05+ trucks there have been an above normal instance of having the caliper lockup with a sticking piston. Those a mechanic is not going to visually see and often the only choice is to replace the caliper and hope that the rebuilt caliper is going to have a better result.
A third less common issue which happens more with age, with lifts, or mechanical damage during caliper removal is an internal tear in a brake hose which becomes a fluid trapping bubble of the inner ply.
Your first two descriptions are common for these situations:
- The pads are kept in contact with the rotor due to non- release situation.
- With the heat generated from contact friction the pads expand and generate more friction with the added pressure, increasing the temp and other adverse aspects.
- Increased hydraulic pressure or a rocking back of the pads can initiate a release of what is hanging the pads and
you're able to continue on without a continuation of the problem.
If the vehicle has sat for a length of time just like any disc brake vehicles rust can form at the ends of the brake pads where they fit into the caliper brackets and also lock them in place. It doesn't sound like you are doing this though.
Is the occasional slight vibration during a stop or when not stopping?
If when not stopping it could be an indicator that the pads are contacting the rotor. If when stopping then it's likely that due to the brake hang up a hard spot has formed in the rotor(s) so the rotor will need to be replaced. Turning the rotor will not remove the hardness can vibration during stops will return in about 10 k miles.