Safe Service Procedures; Air Brake Troubleshooting - PREVOST H3-41 Maintenance Manual

SECTION 12: BRAKE AND AIR SYSTEM
2. Then turn back the adjuster counterclock-
wise  three "clicks" and check the caliper
running clearance.
• During the turning of the adjuster, you will
notice a changed clicking noise. It is not
caused by a defect of the mechanism.
• Also the "feel" during the rotation of the
adjuster and the position of the spanner
after the 3 clicks has changed.
Depending on the age of the vehicle, it may have
installed on it two different design levels of disc
brake and so there may be 2 different clicking
noises and final positions of the adjuster on the
vehicle.

19. SAFE SERVICE PROCEDURES

Most recently manufactured brake linings no
longer contain asbestos fibers.
asbestos, these linings contain a variety of
ingredients, including glass fibers, mineral wool,
aramid fibers, ceramic fibers, and carbon fibers.
At present, OSHA (Occupational Safety and
Health Administration) does not specifically
regulate these non-asbestos fibers, except as
nuisance dust. Medical experts do not agree
about the potential long-term risks from working
with and inhaling
Nonetheless some experts think that long-term
exposure to some non-asbestos fibers could
cause diseases of the lung, including pneumo-
coniosis, fibrosis, and cancer. Therefore, lining
suppliers recommend that workers use caution
to avoid creating and breathing dust when
working on brakes that contain non-asbestos
fibers.
WARNING
Whenever possible, work on brakes in a
separate area away from other operations.
Always wear a respirator approved by NIOSH
(National Institute of Occupational Safety and
Health) or MSHA (Mine Safety and Health
Administration) during
procedures. Wear the respirator from removal
of the wheels through assembly.
40 PA1621 Maintenance Manual All Series | Revised June 2020
Instead of
non-asbestos fibers.
all brake service
WARNING
NEVER use compressed air or dry brushing to
clean brake parts or assemblies. OSHA
recommends that you use cylinders that
enclose the brake. These cylinders have
vacuums with high efficiency (HEPA (Health
and Environment Protection Agency)) filters
and workman's' arm
equipment is not available, carefully clean
parts and assemblies in open air.
During disassembly, carefully place all parts
on the floor to avoid getting dust into the air.
Use an industrial vacuum cleaner with a
HEPA filter system to clean dust from the
brake drums, backing plates and other brake
parts. After using vacuum, remove any
remaining dust with a rag soaked in water and
wrung until nearly dry.
If you must grind or machine brake linings,
take additional precautions, contact with fiber
dust is higher during these operations. In
addition to wearing an approved respirator, do
such work in an area with exhaust ventilation.
When cleaning the work area, NEVER use
compressed air or dry sweeping to clean the
work area. Use an industrial vacuum with a
HEPA filter and rags soaked in water and
wrung until nearly dry. Dispose of used rags
with care to avoid getting dust into the air. Use
an approved respirator
vacuum cleaners and handling used rags.
Wash your hands before eating, drinking or
smoking. Do not wear your work clothes at
home. Vacuum your work clothes after use
and then launder them separately, without
shaking, to prevent fiber dust from getting into
the air.
Material safety data sheets on this product, as
required by OSHA,
Rockwell and Knorr-Bremse.

20. AIR BRAKE TROUBLESHOOTING

The following tests and check lists have been
designed to identify the cause(s) of a sluggish
performance and/or leaks in the system. These
tests require very little time to perform, and give
you a general idea of the system condition. Each
test is provided with a corresponding check list
sleeves. If such
when emptying
are available from