Disc brake air gap is the clearance between the pads and the disc when the brake is released. Correct air gap prevents dragging while ensuring fast engagement and full torque. Measure it using feeler gauges at multiple points around the disc to confirm even clearance. Uneven readings can indicate misalignment, worn guides, or disc runout.
Setting air gap typically involves adjusting caliper mechanisms, springs, or actuator linkage according to the brake manufacturer’s procedure. The target value is model-specific—never guess, because air gap impacts response time and stroke margin. Too large an air gap can cause slow engagement and reduced emergency performance; too small can cause continuous contact and overheating.
After setting, cycle the brake repeatedly and verify the gap remains stable. For overhead and gantry cranes, consider adding air-gap or wear monitoring where downtime costs are high. Proper air gap control is one of the most effective ways to maintain consistent braking torque and extend pad life.