Bendix Commercial Vehicle Systems VERSAJUST AUTOMATIC SLACK ADJUSTER - Manual (Page 2)

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of the Versajust slack adjuster toward the released position
causes the link to rotate the pinion. The anti-reverse spring
prevents counterclockwise rotation of the shaft and worm,
causing the pinion and clutch spring to slip. The gripping
action of the anti-reverse spring – and slippage of the clutch
spring during release – is due to the direction of the coil
windings of each.
YOKE DESIGNS
The Bendix ® Versajust ™ slack adjuster may be equipped
with either of two yoke designs. Both are designed to permit
installation or removal of the slack adjuster, along with its
yoke body and its attached adjusting linkage.
The brake actuator push rod must thread into the adapter a
minimum of 1 /
2
inch and must not extend more than 7 /
64
inch
beyond the other end of the adapter. The yoke adapters
(quick connect & easy-on) have either a 1 or 1 1 /
4
inch hex
to allow tightening of the brake actuator push rod jam nut.
EASY-ON YOKE (REFER TO FIGURE 2)
The easy-on yoke assembly consists of an adapter which
is threaded internally to match the push rod threads and
externally to match female threads in the yoke. A special
and shaft. Worm and shaft rotation results in worm gear
rotation, which in turn adjusts (or repositions) the brake
camshaft.
When the foundation brake shoes contact the drum, the
camshaft begins to resist rotation and friction between the
worm gear and worm builds, preventing further rotation
of the worm. Brake adjustment ceases at this point and
further rotation of the Bendix ® Versajust ™ slack adjuster will
cause the pinion and clutch spring to slip. The “free play”
between the link teeth and pinion results in a predetermined
lining-to-drum clearance.
BRAKE RELEASE
When the brake application is released, the brake
actuator push rod returns the Versajust slack adjuster
to the released position. During release, the Versajust
slack adjuster rotates back toward the actuator causing
the brake camshaft to again rotate, but in the opposite
direction, and the brake shoes begin to move away from
the drum. As the Versajust slack adjuster rotates back to
the release position, the yoke again pivots causing the link
to be pushed downward into the slack adjuster body. The
“free play” between the link teeth and pinion is taken up
during the initial part of the release. Continued movement
GENERAL SAFETY GUIDELINES
WARNING! PLEASE READ AND FOLLOW
THESE INSTRUCTIONS TO AVOID
PERSONAL INJURY OR DEATH:
When working on or around a vehicle, the following
general precautions should be observed at all times.
1.
Park the vehicle on a level surface, apply the
parking brakes, and always block the wheels.
Always wear safety glasses.
2. Stop the engine and remove ignition key when
working under or around the vehicle. When
working in the engine compartment, the engine
should be shut off and the ignition key should be
removed. Where circumstances require that the
engine be in operation, EXTREME CAUTION
should be used to prevent personal injury resulting
from contact with moving, rotating, leaking, heated
or electrically charged components.
3. Do not attempt to install, remove, disassemble
or assemble a component until you have read
and thoroughly understand the recommended
procedures. Use only the proper tools and observe
all precautions pertaining to use of those tools.
4. If the work is being performed on the vehicle’s
air brake system, or any auxiliary pressurized air
systems, make certain to drain the air pressure
from all reservoirs before beginning ANY work
on the vehicle. If the vehicle is equipped with
a Bendix ® AD-IS ® air dryer system or a dryer
reservoir module, be sure to drain the purge
reservoir.
5. Following the vehicle manufacturer’s recommended
procedures, deactivate the electrical system in a
manner that safely removes all electrical power
from the vehicle.
6. Never exceed manufacturer’s recommended
pressures.
7. Never connect or disconnect a hose or line
containing pressure; it may whip. Never remove
a component or plug unless you are certain all
system pressure has been depleted.
8. Use only genuine Bendix ® brand replacement
parts, components and kits. Replacement
hardware, tubing, hose, fittings, etc. must be of
equivalent size, type and strength as original
equipment and be designed specifically for such
applications and systems.
9. Components with stripped threads or damaged
parts should be replaced rather than repaired. Do
not attempt repairs requiring machining or welding
unless specifically stated and approved by the
vehicle and component manufacturer.
10. Prior to returning the vehicle to service, make
certain all components and systems are restored
to their proper operating condition.
11. For vehicles with Automatic Traction Control (ATC),
the ATC function must be disabled (ATC indicator
lamp should be ON) prior to performing any vehicle
maintenance where one or more wheels on a drive
axle are lifted off the ground and moving.