User's Manual

210
UHB800-CAM
GLOSSARY OF TERMS
Caliper: In an air disc brake system, the clamping device to which the friction material is attached. When
actuated, the caliper applies braking force to both sides of the rotor.
Cam Base Circle Radius: The perpendicular distance from the center of the s-cam to the vector defined by the
center of the cam roller and the intersection of the cam roller with the s-cam profile. Most CBCR are designed to
be at or near 1/2 inch.
Clevis pin: Pin connecting the arm of slack adjuster to a brake chamber push rod yoke.
CMVSS: Canadian Motor Vehicle Safety Standard
Coefficient of Friction: Developed by Friction Materials Standards Institute, a double-letter code printed on the
edge of a brake block to designate its range of aggressiveness. (Example: EE, FF, GG, FG)
Cracked Drum: Brake drum cracked all the way through by excessive heat build-up (perhaps signifying inad-
equate drum weight and/or driver abuse) and/or resurfacing of a drum beyond the manufacturer’s limit.
CTI: Central tire inflation
Dual Brake System: Mandated by FMVSS 121, the use of a dual air system (primary and secondary) in order to
retain braking ability in the event one system fails.
Dust Shield: A plate made of metal or polyethylene that is mounted behind a brake drum to minimize the entry of
dirt and road splash.
EBS: Electronic braking system
ECU: Electronic control unit
Edge Code: The information found the edge of a brake block. Spicer friction edge coding includes the type of
friction and the coefficient of friction.
Emergency Brake System: Not a separate system, emergency braking (in event of air loss) involves various
portions of the parking and service brake systems.
Engine Brake: An optional device that converts a diesel engine into a power-absorbing air compressor to slow a
vehicle on downgrades.
ES: Extended Service, Eaton’s term for brake design using thicker than standard lining.
ESII: Eaton’s redesigned Extended Service brake shoe, introduced in 1996. It employs a new Hot Staked
manufacturing process, redesigned retaining springs, lighter weight and elimination of the tabs from the previous
design table.
Exhaust Brake: An optional device that uses engine exhaust back pressure to slow a vehicle on downgrades.
FC: Fast Change, Spicer’s term for brake design with an open anchor pin rib. Interchanges with Rockwell Q
design.
FCII: Spicer’s redesigned 12-1/4 Fast Change brake shoe, introduced in 1996. It includes a redesigned table,
thicker rib material, an improved welding process, and standardization of brake hardware components.
FMSI: Friction Materials Standards Institute