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.
A. With the brake chamber in the released position, |
place a square (or an equivalent object) so that one |
edge is parallel to the actuator push rod, while the |
other edge bisects the brake camshaft. Measure |
the distance from the push rod end to the vertical |
edge of the square and compare it to the values in |
PUSH ROD
15/16"
JAM NUT
MOUNTING
STUD
ADAPTER
YOKE
3/8" OUT
Figure 4. |
BRAKE ACTUATOR |
PUSH ROD |
SQUARE |
DISTANCE |
"A" |
MOUNTING |
STUD |
FIGURE 2 - EASY-ON YOKE ASSEMBLY
QUICK‑CONNECT YOKE
The adapter bushing in this case is threaded internally to match the push rod, but is designed to slide into the yoke. A retainer ring is used to secure the adapter bushing in the yoke. (Refer to Figure 3.)
|
| "A" Std. |
|
|
| ||
Slack Adjuster |
| Quick Connect or |
|
| "A" Extended | ||
Arm Length |
|
|
|
| |||
5" | 115/16" - | 31/32" |
| 27/16" - 317/32" |
| ||
51/2" | 115/16" - | 33/16" |
| 27/16" - 311/16" |
| ||
6" | 13/16" - | 33/16" |
| 111/16" - 311/16" |
| ||
PUSH ROD
1"
JAM NUT
MOUNTING
STUD
ADAPTER
BUSHING
RETAINING RING
YOKE
FLUSH
FIGURE 4 - MEASURING THE BRAKE ACTUATOR PUSH ROD
B. If the measurement is less than the minimum shown |
in Figure 4, the brake actuator push rod must be |
shortened. If the measurement is greater than |
the maximum values, the brake actuator push rod |
may require replacement. The extended adapter – |
available as a separate service part |
297700 and 1/2"‑20 pc. no. 297701) – may avoid |
the need to replace the brake actuator push rod. |
The extended adapter is available for the easy‑on |
yoke assembly only. Note: Installing any other |
type of push rod extender is not recommended. |
These devices may loosen over time and result in |
an improperly adjusted brake. |
FIGURE 3 - QUICK-CONNECT YOKE ASSEMBLY
INITIAL INSTALLATION PREPARATION
1.If necessary, carefully remove the manual or automatic slack adjuster currently installed, including the brake chamber yoke assembly.
2.Before mounting the Bendix® Versajust™ slack adjuster on the camshaft, check the brake chamber push rod length to determine whether shortening or replacement is required. To accomplish this:
3. Inspect the foundation brake, brake chamber, and |
related components. Make certain the camshaft |
bushings and seals are not excessively worn. Lubricate |
the camshaft bushings. Check the brake chamber |
bracket for cracks and excessive corrosion. The brake |
actuator push rod should not be loose or bent, and the |
return spring should be firm. Replace parts that are |
suspect. |
4. Wire brush the foundation brake camshaft to loosen |
contamination and wipe clean. Depending on |
3