Hyundai 100D-7 Operating Manual page 194

Prepare housing and check the air gap
Lay discs into the housing.
Check the air gap
Air gap = measure A-measure B(measured without pressure)
Rated size about 0.5mm smaller than the air gap pressurized(see table).
Install O-ring(brake housing / brake carrier) free of torsion and loops.
Air gap and wear dimension
Brake type
5340
Air gap sL new(Pressurized) (mm)
2.4 0.9
3-146
100D7XL87
Wear dimension(mm)
2.0