Landoll 345B, Operator'S Manual

Page: 47 / 66

5. Install shoes, anchor pin bushings, anchor
pins, and spacers onto spider. Install
anchor lock rings.
IMPORTANT
ALWAYS USE ALL NEW SPRINGS WHEN
SERVICING BRAKES.
6. Install brake return spring.
7. Connect slack adjuster to brake chamber
pushrod.
8. Adjust automatic slack adjuster as outlined
in Section 4-8.6 c.
4-8.6 Automatic Slack Adjusters
The trailers automatic slack adjusters provide
the means for routine brake adjustment to compen-
sate for lining wear. Inspect slack adjusters every
2,000 miles to assure correct operation.
a. Operational Check (See Figure 4-11)
1. Block wheels to prevent vehicle from
rolling.
2. Check that the push rod is fully retracted,
apply air to release spring brake.
3. Turn adjustment hex counterclockwise to
create an excessive clearance condition.
(A ratcheting sound will occur.)
4. Make a full service brake application. On
release, allow sufficient time for brake to
fully retract. During the brake release,
observe rotation of the adjustment hex
(attach a wrench on the hex to make this
movement easier to see). This rotation
indicates that an excessive clearance
condition has been determined by the slack
adjuster, and it is making an adjustment to
compensate. On each subsequent brake
release the amount of adjustment and push
rod travel will be reduced until the desired
clearance is achieved
5. The push rod stroke should be 1 1/2" to 2"
with an 100 to 105 PSI service brake
application.
6. Measure the movement of the push rod
from the completely released position to
the applied position by marking the push
rod where it exits the air chamber before
and after application.
4-17
Figure 4-11 Slack Adjuster