BENDIX PIGGYBACK SPRING BRAKE Manual

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Bendix Piggyback Spring Brake
FIGURE 1 - BENDIX PIGGYBACK SPRING BRAKE
DESCRIPTION
The Bendix Piggyback Spring Brake is made up of a
conventional brake chamber and an emergency or parking
spring mechanism for use on vehicles equipped with cam
foundation brakes. The Spring Brake Actuator provides: (1)
Service Braking, (2) Parking and (3) Emergency Braking.
The actuator can be piped with various system arrangements
to be automatically or manually applied under emergency
braking conditions.
The spring brake is a diaphragm type actuator which converts
the energy of air pressure into mechanical force. The
diaphragm is held between the pressure plate and non-
pressure plate by a two piece clamp ring.
Different size brake chambers are identified by numbers
which specify the effective area of a diaphragm. For example,
a Type 30/30 Spring Brake has 30 square inches of effective
area on each diaphragm.
The standard diaphragm material is a compound of natural
rubber with a fabric interior of nylon.
SERVICE PUSH-ROD
SERVICE
CHAMBER
SERVICE
DIAPHRAGM
PIGGYBACK CHAMBER
PREVENTIVE MAINTENANCE
Important: Review the warranty policy before performing
any intrusive maintenance procedures. An extended warranty
may be voided if intrusive maintenance is performed during
this period.
Because no two vehicles operate under identical conditions,
maintenance intervals will vary. Experience is a valuable guide
in determining the best maintenance interval for a vehicle.
WARNING!
Piggyback Spring Brake Chambers contain a loaded
compression spring. Property damage, serious injury
or death may occur if instructions are not followed
completely.
Every 300 operating hours, 8,000 miles, or one (1) month:
1. Check push rod travel and adjust travel at the slack
adjuster if needed. Push rod travel should be as short
as possible without the brakes dragging. Excessive push
rod travel reduces braking efficiency, shortens diaphragm
life, gives slow braking response and wastes air.
1