Various approaches to truck disc brake design are discussed. Design of the disc and the effect of its design on brake performance show current designs being proposed may be inadequate. Lining area must be adequate for long life without restricting cooling. Piston retraction and adjustment by mechanical means is more reliable than seal retraction. A multiple disc oil-cooled hydraulic disc brake can provide extended life and high torque in a small diameter package. Air-actuated disc brakes eliminate the need for hydraulics, but introduce problems in force multiplication and brake-to-brake balance.
