Slack Adjusters; Haldex Automatic Slack Adjuster - Midland SIDE DUMP GRAVEL TRAILER Operator's Manual

5.2.9

SLACK ADJUSTERS

5.2.9.1

HALDEX AUTOMATIC SLACK ADJUSTER

The Haldex S-ABA automatic brake adjuster
is a clearance sensing brake adjuster that
maintains a nominal distance or clearance
between lining and drum.
When the Adjuster is Installed:
With the brake in the released position, the
control arm is fixed to the anchor bracket.
The adjustment hex is rotated until the
shoes contact the brake drum and then
backed
off 1/2 turn. When the brake is applied
on the first application, the endless rack
rotates to the correct position and sets
itself.
When the Brake Applies:
When the brake is applied, the adjustment
regulator rotates through the normal
clearance angle and the shoes contact
the drum. The torque increases and the
Fig. 59 HALDEX SLACK ADJUSTER (TYPICAL)
wormshaft is moved axially, causing the coil
spring to be compressed and the clutch
wheel to disengage. The adjustment components are
free to rotate as the brake continues to apply.
When the Brake Releases:
When the brake is released, the torque decreases
returning the wormshaft to the clutch wheel and
re-engaging the teeth. The adjustment regulator
rotates through the normal clearance angle and the
brake is released. If lining wear has taken place the
adjustment regulator advances the clutch wheel
reducing the excess clearance during the release
stroke.
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