Air Drum Brake Component Specifications. GMC Truck TopKick C-Series (Conventional) C4/C5 2008

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2008 🢒 TopKick C-Series (Conventional) C4/C5 🢒 Brakes 🢒 Air Drums 🢒 Air Drum Brake Component Specifications

Application	Specification
Application	Metric	English
Brake Drums
Drum Diameter New - 15 in	381 mm	15 in
Drum Diameter New - 16.5 in	419.10 mm	16.50 in
Drum Maximum Allowable Diameter After Refinish - 15 in	383.946 mm	15.1196 in
Drum Maximum Allowable Diameter After Refinish - 16.5 in	422.04 mm	16.61996 in
Drum Maximum Discard Diameter - 15 in	384.048 mm	15.120 in
Drum Maximum Discard Diameter - 16.5 in	422.148 mm	16.620 in
Out-of-Round Maximum Dimension	0.38 mm	0.015 in
Taper or Barrel Shape Maximum Dimension	0.25 mm	0.010 in

U.S. DOT Stroke Limits 80-90 psi (550-620 kPa) Pressure In Air Chamber Clamp Type Air Chamber
Chamber Type (Size)	Adjust The Stroke As Short As Possible Without The Brakes Dragging	Desired Free Stroke (Without Drag)
16	Less Than 1-3/4 in (44.4 mm)	3/8-1/2 in (9.5-12.7 mm)
20	Less Than 1-3/4 in (44.4 mm)	3/8-1/2 in (9.5-12.7 mm)
24	Less Than 2 in (50.8 mm)	3/8-5/8 in (9.5-15.9 mm)
30	Less Than 2 in (50.8 mm)	3/8-5/8 in (9.5-15.9 mm)