2.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.
3.Perform the In Service Inspection described in this manual.
IN SERVICE INSPECTION
1.Apply and release the vehicle brakes several times while observing the Bendix® Versajust™ slack adjuster. The Versajust 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 Versajust 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
| Recommended |
Brake Actuator | Maximum |
Size | Operating Stroke |
|
|
30 | 2" |
|
|
24 | 13/4" |
20 | 13/4" |
16 | 13/4" |
12 | 13/8" |
LONG STROKE | |
| Recommended |
Brake Actuator | Maximum |
Size | Operating Stroke |
|
|
30LS | 21/2" |
24L | 2" |
|
|
24LS | 21/2" |
20L | 2" |
16L | 2" |
|
|
CHART 2 - ACTUATOR STROKE TABLE
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 Chart 2, on this page. The correct pressure for this test can be achieved as follows: Build the system pressure up to a 100 psi reading on the vehicle gauge. Shut the engine off. Fan the brakes to attain a 90‑95 psi reading. Make and hold a full brake application while the strokes are checked.
IF THE SLACK ADJUSTER DOES NOT AUTOMATICALLY ADJUST THE BRAKES
If the actuator stroke exceeds those shown in the stroke table, inspection of the foundation brake and/or the automatic slack is necessary. Maintenance of the foundation brake may be a factor in the excessive stroke conditions. Inspecting the foundation brake – per the
Brake Maintenance Inspection presented in this manual –
should determine how much of the long stroke condition is caused by the condition of the foundation brake. The Bendix Versajust slack adjuster can be tested using the instructions presented in this manual under "Testing the Bendix® Versajust™ Adjuster Mechanism." The automatic slack adjuster is not designed to function as a manual adjuster once it is unable to maintain adjustment automatically. Manual adjustment should be done only as a temporary measure to correct brake adjustment in an emergency situation. The routine manual adjustment of an automatic slack adjuster that is still within adjustment limits may shorten its service life. Automatic slack adjusters should not be manually adjusted in an effort to correct excessive push rod stroke. This condition indicates that a problem exists with the automatic adjuster; with the installation of the adjuster; or with related foundation brake components, which manual adjustment will not fix. Replacement of the automatic slack adjuster or other foundation brake components may be necessary. Consult
with the manufacturer's troubleshooting guidelines to find and fix the problem.
WARNING: Manual adjustment of automatic slack adjusters is a dangerous practice that could have serious consequences. This is because it can give the operator a false sense of security about the effectiveness of the brakes, which are likely to go out of adjustment again soon. Do not make manual adjustments of an automatic slack adjuster once it can no longer automatically adjust the brakes. Manual adjustment DOES NOT fix the underlying wheel end adjustment problem. As soon as possible, have the vehicle inspected by a qualified technician or consult the manufacturer's troubleshooting guidelines to find and fix the problem.
5
