MCi Crusader II 1989 Maintenance Manual page 158

Date
1-1-89
Page ___
4-_2s _ _
MC-9 MAINTENANCE MANUAL
Figure 4-34. Manual Slack Adjuster Installed.
Figure 4-35. Typical Slack Adjusters.
SLACK ADJUSTERS (MANUAL)
Slack adjusters provide a quick method of adjusting brakes
to compensate for brake lining wear (figures 4-34 and 4-35).
The slack adjusters utilize wo·rm gear drive to ensure maximum
road service with a minimum of maintenance.
Slack adjusters must be lubricated once every 5,000 miles
(8,000 km). The slack adjuster grease fittings may be lubricated
with
a standard shop grease gun. Only molybdenum disulphide
grease should be used on the slack adjusters.
BRAKE ADJUSTMENT
CAUTION: Prior to adtusting the rear coach
brakes, ensure that system air pressure is
above 65 psi (449 kPa).
While making brake adjustments, the wheel must be in a
jacked-up position. ·
1. Install the wrench on the adjusting screw and disengage
the locking sleeve by depressing it While the locking sleeve is
in the depressed position, calibrations may be made by turning
the adjusting screw.
2. Turn the adjusting screw until the brake shoes are tight
against the brake drum (brake chamber push rod in the
released. position).
3. Back off the adjusting screw two notches on the front units
and three notches on the rear units.
4. When all adjustments have been completed. ensure-that
the locking sleeve is returned to a locked position by permitting
it to engage the hexagon head of the adjusting screw.
CAUTION: All the slack adjusters on the
coach must be at the same angle.
REMOVAL AND INSTALLATION
1. To remove a slack adjuster, remove the brake chamber
push rod yoke pin. capscrew, and the snap ring which holds the
slack adjuster onto the brake camshaft.
2. Slide the slack adjuster off the spline end of the camshaft
3. When installing a slack adjuster, clearance must be
allowed to ensure that the slack adjusters car, be rotated to the
maximum stroke of the brake chamber. Install the grease fitting
and locate the siack adjuster on the camshaft in such a manner
as to allow both the adjuster screw and grease fitting easy
access when servicing.
4. Install the retaining ring onto the end of the slack adjuster
in order to hold the slack adjuster in place.
Refer to Operating Test to ensure that proper adjustments
are made to provide for these conditions when installing the
slack adjuster.
OPERATING TEST
1. Apply the coach brakes and inspect to ensure that the
slack adjusters rotate freely and without binding.
2. Release the brakes and check to be sure that slack adjus-
ters return to a released position freely without binding.
AUTOMATIC SLACK ADJUSTERS (OPTIONAL)
Automatic slack adjusters are designed to resist wear and to
function for longer periods on coaches under severe service
conditions. Because of the slack adjuster's importance, the
coach comes f, om the factory with the cover plates welded in
place. This ensures that no tampering is done with the internal
components of the adjuster. See figures 4-36.
The automatic slack adjuster consists of a worm shaft and
wheel combined with an adjusting· mechanism. The worm
wheel is attached to the brake camsha~