27
F) Slack adjuster
Automatic slack adjuster – adjustment Type HALDEX
• Set cams and brake shoes to released position.
• Observe the correct push rod length “L” as
indicated in the SAF specifications.
•
Membrane brake cylinder
Before installing the automatic slack adjuster,
ensure that the brake chamber push rod is in
released position.
• By contrast,
spring brake chambers
must be under
full operating pressure (min. 6 bar).
IMPORTANT: If this is not maintained properly, the
basic setting will be wrong, with critical effect of
overheating the brakes.
• Grease the camshaft.
• Install anchor bracket (3), being sure to use two
fixing bolts (4), do not yet tighten the bolts.
• Install the slack adjuster on the camshaft.
• The arrow (7) points in the braking direction.
• Turn adjusting screw (1) until the bore in the slack
adjuster (8.1) coincides with the bore in the clevis
end (9) (see drawing).
• Grease split pin (8) and secure.
• Install return spring (10).
• Move the control arm (2) in the direction of the
arrow (operating direction of slack adjuster) up to
its end position “A”
without
applying excessive
force.
• When control arm (2) is in its end position “A”,
tighten the fixing bolts (4).
• For the anchor bracket mounting (11), ensure that
the 2 U-profiles engage firmly together.
• Fit slack adjuster retaining clip on camshaft.
• Axial clearance: Adjust 0.5 - 2 mm using shims.
• Adjust running clearance between brake lining and
drum by turning adjusting screw (1) in clockwise
direction until the lining fits smoothly against the
drum. Then back off adjusting screw (1) by 3/4 turn.
Do not use impact wrenches!
FUNCTION CHECK
• If the self adjuster is functioning correctly, then a
minimum torque of 18 Nm must be felt and a
grating noise must be heard when adjusting screw
(1) is backed off.
• Operate the footbrake several times. Check whether
the brake drum rotates freely, check the lining
clearance and repeat adjustment procedure if
necessary.
11
2
1
4
3
7
2
10
L
