Bendix Commercial Vehicle Systems ASA-5 AUTOMATIC SLACK ADJUSTER 2/11 - Manual (Page 5)

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Visually check for physical damage such as broken air lines
and broken or missing parts.
Every 25,000 miles, or 3 months, or 500 operating hours
or at the time of routine vehicle chassis lubrication,
whichever occurs first, the following steps should be
followed (Also observe any shorter brake adjustment
inspections or maintenance intervals specified by the
vehicle manufacturer):
1. Lubricate the automatic slack adjuster through the lube
fitting with a quality multipurpose chassis lubricant
(N.L.G.I. Grade 2).
Lubricate the slack adjuster until clean lubricant flows
from the grease relief opening in the boot.
2. Perform the In Service Inspection described in this
manual.
IN SERVICE INSPECTION
1. Apply and release the vehicle brakes several times
while observing the ASA‑5 ® slack adjuster. The ASA‑5 ®
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 yoke and adapter bushing and the yoke
and link pins and their mating parts (yoke, body, link).
Replace these parts if looseness appears excessive.
Make certain the brake actuator push rod jam nut is
tight against the yoke adapter.
2. Inspect the ASA‑5 ® slack adjuster for physical damage
paying particular attention to the link, boot and yoke.
Inspect for bent, broken, loose or misaligned brake
actuator push rods and cracked or damaged brake
actuator brackets. Repair or replace any components
found to be damaged.
ACTUATOR STROKE TABLE
STANDARD STROKE
Brake Recommended Maximum
Actuator Size Operating Stroke
30 2"
24 1-3/4"
20 1-3/4"
16 1-3/4"
12 1-3/8"
LONG STROKE
Brake Recommended Maximum
Actuator Size Operating Stroke
30LS 2-1/2"
24L 2"
24LS 2-1/2"
20L 2"
16L 2"
3. Measure the brake actuator push rod stroke while
making an 80‑90 psi service brake application. Actuator
push rod strokes should not exceed the values shown
in the following actuator stroke tables. The correct
with the end of the brake actuator push rod. Install the
retaining ring on the adapter bushing, making certain
it is in the adapter bushing groove. Turn the ASA‑5 ®
slack adjuster manual adjustment hex clockwise until
the adapter bushing begins to enter the yoke. Fully
compress the retaining ring “legs” and con tinue turning
the ASA‑5 ® slack adjuster manual adjustment hex un til
the adapter bushing is completely in the yoke. Allow
the retaining ring to expand into the cor responding
groove in the yoke. Make certain the retaining ring is
seated in both the yoke and the adapter bushing groove
by manually pulling the ASA‑5 ® slack adjuster arm,
attempting to separate the adapter bushing and
yoke.
5. Run the brake actuator push rod jam nut down against
the adapter or adapter bushing. Hold the adapter or
adapter bushing hex with a wrench and tighten the jam
nut to 300‑400 inch pounds for the 1/2"‑20 thread and
400‑600 inch pounds for the 5/8"‑18 thread.
6. Manually adjust the brakes.
Note: The vehicle brakes should be adjusted using the
vehicle or brake manufacturer’s recommendation. If
they are not available, the following procedure can be
used: Rotate the manual adjustment hex clockwise
until the linings are snug against the drum. Turn the
adjustment hex counterclockwise 1/2 turn. Pull the
actuator push rod to confirm that approximately 1/2 inch
of push rod free stroke exists. Apply 85 psi and check
that the push rod stroke is below the readjustment limit.
If the stroke ex ceeds the readjustment limit, check
the condition of the foundation brake. Refer to Brake
Maintenance Inspec tion.
7. Manually uncage the spring brakes before return ing
the vehicle to service.
8. With the ASA‑5 ® slack adjuster installed, check to
ensure clearance requirements with the brake fully
releas ed and at the actuator’s maximum stroke. Also
con sider clearances with the vehicle suspension
springs depressed to the jounce bumpers, as well as
in rebound.
PREVENTIVE MAINTENANCE
Important: Always review the Bendix Warranty Policy
before performing any intrusive maintenance procedures.
A warranty may be voided if intrusive maintenance is
performed during the warranty period.
No two vehicles operate under identical conditions, as
a result, maintenance intervals may vary. Experience is
a valuable guide in determining the best maintenance
interval for air brake system components. At a minimum, the
ASA‑5 ® slack adjuster should be inspected every 3 months
or 500 operating hours, whichever comes first, for proper
operation. Should the ASA‑5 ® slack adjuster not meet the
elements of the operational tests noted in this document,
further investigation and service of the adjuster may be
required.