TESTING THE BENDIX® VERSAJUST™ ADJUSTER MECHANISM
The following test can be made to determine if the Bendix® Versajust™ adjuster mechanism is functioning properly.
1.With the brakes released and the vehicle wheels blocked, de‑adjust the brakes by rotating the manual adjustment hex counterclockwise approximately 1/2 to 1 revolution.
Note: Considerable torque is required to rotate the manual adjustment hex counterclockwise and should be considered normal. The required torque may be as high as 70 foot pounds.
2.Using a straight edge, scribe a line across the manual adjustment hex head and slack adjuster body. (Refer to Figure 6).
ADJUSTER HEX
ROTATES
CLOCKWISE
DURING
ADJUSTMENT
GREASE
FITTING
FIGURE 6 - TESTING ADJUSTER MECHANISM
3.Apply, and COMPLETELY RELEASE, the service brakes several times while observing the manual adjustment hex and the scribed line. The Bendix Versajust slack adjuster manual adjustment hex should rotate clockwise during the application and remain stationary during release. No counterclockwise rotation of the hex should be observed. The amount of clockwise rotation (adjustment) will decrease progressively as the brake nears proper adjustment. If the Versajust slack adjuster fails to perform as described, it will be necessary to repair or replace it.
4.Manually
Note: While it is possible to use the automatic adjustment feature of the Versajust slack adjuster to bring the brake back into adjustment, this process will require numerous applications and COMPLETE RELEASES (the number of applications depends on how much the slack was de‑adjusted).
BRAKE MAINTENANCE INSPECTION
Note: Make certain the vehicle has been prepared according to the instructions under the heading GENERAL SAFETY GUIDELINES in this manual.
The following test can be used to inspect the maintenance condition of the foundation brake and to determine how much of the chamber stroke is caused by the condition of the foundation brake.
1.Always chock the wheels to keep the vehicle from moving.
2.Raise the axle so the wheel can be rotated.
3.Adjust the slack adjuster to produce light brake drag with wheel rotation.
4.Apply the brake to 80‑90 psi and measure the stroke (See Item 3 of In Service Inspection for pressure tips).
5.If the stroke significantly exceeds the values shown in
Chart 3 below, the brake may be out of the norm, and brake maintenance may be required.
| 15"x4" | 16.5"x7" | 16.5"x7" |
AL | Front | Tractor, Truck | Trailer |
Factor | Brake | or Bus Brake | Brake |
|
|
|
|
12 X 5.0" | 1/2" | N/A | N/A |
12 X 5.5" | 1/2" | N/A | N/A |
16 X 5.0" | 5/8" | 1/2" | N/A |
16 X 5.5" | 3/4" | 1/2" | N/A |
16 X 6.0" | 7/8" | 5/8" | N/A |
20 X 5.0" | 5/8" | 1/2" | 3/8" |
20 X 5.5" | 3/4" | 5/8" | 1/2" |
20 X 6.0" | 7/8" | 3/4" | 5/8" |
24 X 5.0" | N/A | 5/8" | 1/2" |
24 X 5.5" | N/A | 5/8" | 5/8" |
24 X 6.0" | N/A | 3/4" | 5/8" |
30 X 5.0" | N/A | 3/4" | 5/8" |
30 X 5.5" | N/A | 7/8" | 3/4" |
30 X 6.0" | N/A | 1" | 7/8" |
CHART 3 - AL FACTOR
BENDIX® VERSAJUST™ SLACK
ADJUSTER REMOVAL
Note: Make certain the vehicle has been prepared according to the instructions under the heading GENERAL SAFETY GUIDELINES in this manual.
1.If the Versajust slack adjuster is equipped with the easy‑on yoke assembly illustrated in Figure 2:
A.Loosen the brake actuator push rod jam nut and run it back on the brake actuator push rod approximately 5/8 inch.
B.Loosen the easy‑on yoke adapter and run it back on the brake actuator push rod until it is free of the yoke.
6