1.
Visually check for physical damage, such as bro-
ken air lines and broken or missing parts.
2.
Using a quality multipurpose chassis lubricant,
NLGI Grade 2, lubricate the slack adjuster
through the grease fitting until clean lubricant
flows from the grease relief opening in the boot.
3.
Perform the "In Service Inspection."
In Service Inspection
1.
Apply and release the brakes several times while
observing the slack adjuster. The slack adjuster
and brake actuator should move freely, without
binding or interference, and should return to the
full released position. Observe the looseness that
exists between the clevis and adapter bushing
and the yoke and link pins and their mating parts
(clevis, body, link). Replace these parts if loose-
ness appears excessive. Make certain the brake
actuator pushrod jam nut is tightened securely.
2.
Inspect the slack adjuster for physical damage,
paying attention to the link, boot, and clevis. If
any components are damaged, repair or replace
them as necessary.
3.
Measure the brake actuator pushrod stroke while
making an 80 to 90 psi (552 to 621 kPa) brake
application. Actuator pushrod strokes should not
exceed the values shown in
and
. To achieve the correct pressure for this
test, build the system pressure up to a 100 psi
(690 kPa). Shut down the engine. Fan the
brakes to attain a 90 to 95 psi (621 to 655 kPa)
reading. Make and hold a full brake application
while the strokes are checked.
Actuator Stroke–Standard Stroke
Brake Actuator Size
Recommended Maximum
Operating Stroke (Inches)
30
2
24
1-3/4
20
1-3/4
16
1-3/4
12
1-3/8
Table 2, Actuator Stroke–Standard Stroke
Actuator Stroke–Long Stroke
Brake Actuator Size
Recommended Maximum
Operating Stroke (Inches)
30 Long Stroke
2-1/2
24 Long
2
24 Long Stroke
2-1/2
20 Long
2
16 Long
2
Table 3, Actuator Stroke–Long Stroke
Brakes
42
Business Class M2 Maintenance Manual, November 2015
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