Bendix Commercial Vehicle Systems ASA-5 AUTOMATIC SLACK ADJUSTER 2/11 User Manual

Page 2

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2

ADAPTER

BUSHING

YOKE

YOKE PIN

LINK PIN

BOOT

LUBE

RELIEF

OPENING

CLUTCH

SPRING

WORM

ANTI-

REVERSE

SPRING

SPRING

RETAINER

WORM

GEAR

FIGURE 2 -

SECTIONAL VIEW OF PROFILE AND END

MANUAL

ADJUSTER

HEX

FREE

PLAY

YOKE DESIGNS

ASA‑5

®

slack adjusters may be equipped with either of two

yoke designs. Both are designed to permit installation or

removal of the slack adjuster along with its yoke body and

its attached adjusting linkage.

The brake actuator push rod must thread into the adapter

a minimum of 1/2 inch and must not extend more than

7/64 inch beyond the other end of the adapter. The yoke

adapters (quick connect & easy‑on) have either a 1 or

1‑1/4 inch hex to allow tightening of the brake actuator

push rod jam nut.

EASY-ON YOKE (REFER TO FIGURE 3)

The easy‑on yoke assembly consists of an adapter which

is threaded internally to match the push rod threads and

externally to match female threads in the yoke. A special

extended yoke adapter is also available as a separate

service item. The extended adapter is 1/2 inch longer than

the standard and is primarily intended for use when the

existing brake actuator push rod is too short.

of the worm. Brake adjustment ceases at this point and

further rotation of the ASA‑5

®

slack adjuster will cause the

pinion and clutch spring to slip. The “free play” between

the link teeth and pinion results in a predetermined lining

to drum clearance.

BRAKE RELEASE

When the brake application is released, the brake actuator

push rod returns the ASA‑5

®

slack adjuster to the released

position. During release, the ASA‑5

®

slack adjuster rotates

back toward the actuator causing the brake camshaft to

again rotate, but in the opposite direction, and the brake

shoes begin to move away from the drum. As the ASA‑5

®

slack adjuster rotates back to the release position the yoke

again pivots causing the link to be pushed downward into

the slack adjuster body. The “free play” between the link

teeth and pinion is taken up during the initial part of the

release. Continued movement of the ASA‑5

®

slack adjuster

toward the released position causes the link to rotate the

pinion. The anti‑reverse spring prevents counterclockwise

rotation of the shaft and worm causing the pinion and clutch

spring to slip. The gripping action of the anti‑reverse spring

and slip page of the clutch spring during release is due to

the direction of the coil windings of each.

PINION

LUBE

FITTING

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