TRUCK SERVICE MANUAL
BRAKES-AIR
GENERAL
GENERAL INSTRUCTIONS
Item 3
Bendix Westinghouse 291 126 (1/4 oz.) or BW 191
Air brake equipment on trucks and truck tractors
127 (2 oz.) silicone grease intended primarily for dynamic
provides a means of controlling the brakes through the
lubrication between oil resistant rubber seals and metal
medium of compressed air.
parts. Meets
' MILL4343A requirements. Can be
Air brake equipment consists of a group of devices;
used in serviceable range of 65 degrees F to +800
some maintain a supply of compressed air, some direct
degrees F. Causes less swelling and hardness change
and control the flow of the compressed air and others
of rubber parts than normally encountered with
transfer the energy of compressed air into the
mechanical force and motion necessary to apply the
Dow Corning Corporation DC55 pneumatic grease).
brakes. Different types and sizes of devices are in use
on different types of vehicles to meet operating
requirements.
LEAKAGE TESTS
In most cases where leakage tests are performed on
The components used to make up a typical dual
various components, a soap bubble test can be made to
air system on a chassis are listed in this section with a
determine if the items need repairs. However, to assist
brief description, operation, service checks and
in locating any leakage at connections or at any
maintenance procedures.
components, we suggest that a Leak Detector Tester
(SE2326) be used to locate any air leaks.
for some components.
With special attachments contained in the tester a
CAUTION: Whenever any component is
very small air leak can be detected easily; for example, in
serviced or removed from the air
a confined area where a brush with soap is obstructed.
system, be sure to set the parking brake
and/or block the vehicle to prevent it
from moving while the service is being
performed.
LUBRICANT SPECIFICATIONS
Throughout the text whenever a particular
lubrication note and a particular item number is made,
refer to the following list of item numbers and use the
lubricant specified.
Item 1
IH 251H EP grease or equivalent to NLGI #2
multipurpose lithium grease (same as BW 226M and
204M lubricant).
Item 2
Fig. 1
Leak Detector Tester (SE2326)
Bendix Westinghouse 239 377 (2 oz.)
molybdenum disulfide lubricant in liquid carrier. A
lubricant suited for O ring powder suspended in synthetic
lubricant (polyalkylene glycol derivative) and rubber parts
as well as metal lubrication, especially at low
temperatures.
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