1
Bendix Brake Chambers
SD-02-1302
CLAMP RING
PUSH ROD
ASSY.
CLAMP RING
NUTS & BOLTS
INLET PORT
NON
PRESSURE
PLATE
SPRING
INLET PORT
PRESSURE PLATE
DIAPHRAGM
DESCRIPTION
The brake chamber 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 either a one piece clamp ring or a two
piece clamp ring (Figs. 1 and 2).
Different size brake chambers are identified by numbers
which specify the effective area of the diaphragm. A type
30 brake chamber has 30 square inches effective area.
Since one side of a brake chamber diaphragm is exposed
to the applying air pressure and the other side to atmospheric
pressure, the chamber has a pressure and a non-pressure
side. The non-pressure plate is usually vented to atmosphere
with four holes, however, on those installations where the
chamber must be weather-proof, venting is accomplished
through a drilled passage in the mounting bolts and the rod
opening in the non-pressure plate is sealed by either a
boot or an o-ring seal.
The standard diaphragm material is a compound of natural
rubber with a fabric interior of nylon. Neoprene-nylon
diaphragms are optionally available.
Smaller chambers such as type 3 and type 6 have one 1/4
in. NPT inlet port in the center of the pressure plate. Larger
size chambers may have a center port and a side located
port or either one. Current production Type 20 chambers
and larger, generally have 3/8 in. NPT ports to facilitate
compliance with FMVSS 121.
LOCK NUT
YOKE
MOUNTING
BOLTS
