3406A Hp.

This issue we have had is that they have piston/pistons pushing from the inside applying pressure to the inside of the disk with bolts or rods that slide through the caliper and pull the far side friction disk against the outside side of the disk using the same piston.
If these slidey bits get sticky due to mud or dirt they only brake on the inside. You dont feel it as they still have 50% the friction area and because they are so powerful you may not notice. Then on inspection you see one side taking all the wear. On normal operations it does not happen often but in poor conditions it comes up a lot. In Europe they are standard fitment on most trucks except tipper/muck trucks. As far as maintenance , you can change brakes on a wheel in 30 min if you use 20 for taking the wheels off.
Try that on drums.

 

Can you typically get away without turning the rotors when you change pads?

 

The 388's here see dirt every day but probably not like Johannesburg. The older ones were really bad on concrete trucks and would expect the same with the new ones.