School bus – Bendix Commercial Vehicle Systems BRAKE APPLICATION GUIDELINES User Manual

Page 29

Defi nitions

Transporting students to and from school and/ or school related events

Operation on road surfaces of concrete, asphalt, maintained gravel, crushed rock, or hard packed dirt

Two (2) stops per mile are considered typical

100% load going / empty return (typical)

Typical Vehicle Types

Front Engine Commercial Chassis

Front Engine Integral Coach

Rear Engine Integral Coach

Vehicle Confi gurations

4 x 2 straight bus

General Requirements

• Anti-compounding air system
• Cam same operation for all brakes
• Air chamber bracket with gusset for all school bus applications, see page 45
• Air chamber bracket assembly gusset and additional camshaft bracket support see page 45, attached to the axle housing

when the:

a. Brake centerline to air chamber centerline distance (BCCC dimension) is greater than 343 mm [13.5”]
b. Application use a type 30/36 or 36/36 Spring brake chambers.
c. Camshaft brackets with BCCC dimension of less than 8.12" does not require a gusset or additional support.
d. Super Single Tire (Wide Base)
Note: The above support can be supplied by BSFB or the vehicle manufacturer but

must be approved by BSFB Application Engineering Department.

• Applications for use in countries other than the USA and Canada must be reviewed by BSFB Application Engineering.
• Vehicle manufacturer is responsible for air system design, parking and stopping distance performance.
• For all S-cam brake models the camshaft input torque is limited to 2545 N•m [22,500 in-lbs].
• Applications on vehicles with fi xed or liftable auxiliary axles (tag or pusher) must be approved on an individual basis by the

BSFB Application Engineering Department, as auxiliary axles may impact the braking performance of the vehicle.

General Recommendations

• Dust shields for all applications
• Use Auxiliary retarders per TMC RP636
• Brake drum / Rotor material specifi cation per SAE J431. Drum / rotor surface fi nish 4.57 micrometers [180 max microinch]

and .38 mm [.015"] runout, when mounted on a hub rotated on bearings. See notes section for Minimum Drum Weight
requirements

• Brake air system balance per TMC RP632

School Bus