YOKE | YOKE PIN |
ADAPTER |
|
BUSHING | LINK PIN |
CLUTCH | BOOT |
SPRING |
|
WORM | LUBE |
| RELIEF |
| OPENING |
ANTI-
REVERSE
SPRINGFREEPINION PLAY
SPRING
RETAINER
MANUAL
ADJUSTER
WORMHEX
GEAR
LUBE
FITTING
FIGURE 2 - SECTIONAL VIEW OF PROFILE AND END
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.
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.
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 slippage of the clutch spring during release is due to the direction of the coil windings of each.
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.
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