The Bendix® Versajust™ Slack Adjuster Troubleshooting Chart
| Symptom |
| Cause |
| Remedy |
1. | Brake Actuator stroke is | A. | Loose actuator push rod jam nut. | A. | Reposition components and torque to |
| too long. |
|
|
| specification. |
| WARNING: Automatic | B. | Excessive clearance between adapter/ | B. | Replace damaged or worn parts. |
| slack adjusters should |
| adapter bushing and yoke due to wear. |
|
|
| not be manually | C. | Excessive clearance between | C. | Replace worn parts. |
| adjusted in an effort to |
| components: yoke pin — yoke link pin — |
|
|
| correct excessive push |
| link yoke pin — body. |
|
|
| rod stroke, because this | D. | Damaged (worn) | D. Replace damaged parts. | |
| condition indicates that |
| splines on slack or camshaft. |
|
|
| a problem exists with | E. | Weak or broken brake actuator return | E. | Replace weak or broken springs. |
| the automatic adjuster, |
| springs. Weak or broken brake shoe |
|
|
| with the installation of |
| return spring. |
|
|
| the adjuster, or with | F. | Worn or broken foundation brake | F. | Repair or replace as required per In |
| related foundation |
| components, including camshaft |
| Service Inspection. |
| brake components, |
| bushings, brake chamber bracket, etc. |
|
|
| which manual | G. | Versajust adjuster mechanism not | G. Lubricate, test adjuster mechanism, | |
| adjustment will not fix. |
| functioning. |
| conduct in service inspection, repair |
|
|
|
|
| components as necessary, replace. |
|
| H. | Brake | H. | Replace or repair as required. |
|
|
| machined, bell‑mouthed, |
|
|
|
|
| excessive thermal expansion. |
|
|
|
|
|
|
|
|
|
| I. | Damaged Versajust slack adjuster. | I. | Replace component(s) or slack adjuster. |
|
| J. | Versajust slack adjuster improperly | J. | Correct installation position. |
|
|
| installed. |
|
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|
|
|
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|
|
2. | Brakes dragging — | A. | Versajust slack adjuster improperly | A. | Correct the Versajust slack adjuster |
| apparent |
| installed. Too close to actuator: brakes |
| installation. |
| of brakes. |
| can’t fully release. |
|
|
|
| B. | Loose actuator push rod jam nut. | B. | Reposition components and torque to |
|
|
|
|
| specification. |
|
|
|
|
| |
|
| C. | Spring brakes not fully retracting. | C. Check spring brake release air pressure | |
|
|
|
|
| and repair or replace air valving as |
|
|
|
|
| necessary. Repair or replace spring |
|
|
|
|
| brake. |
|
|
|
|
| |
|
| D. | Broken foundation brake components, | D. Repair or replace as required per In | |
|
|
| including camshaft bushings. |
| Service Inspection. |
|
|
|
|
|
|
|
| E. | Vehicle brake torque imbalance. (More | E. | Check other brakes to ensure they are |
|
|
| work done by some brakes than others, |
| working. Check air pressure balance |
|
|
| thermal expansion of drums). |
| and threshold pressure (refer to Bendix |
|
|
|
|
| publication BW1555). Check driver |
|
|
|
|
| braking habits, e.g. use of trailer control |
|
|
|
|
| valve. Use same friction material on all |
|
|
|
|
| axles. |
|
| F. | Brake drum out‑of‑round, excessive | F. | Replace or repair as required. |
|
|
| thermal expansion. |
|
|
|
|
|
|
| |
|
| G. | Air system malfunction, not exhausting | G. Inspect and correct. | |
|
|
| completely. |
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|
| H. | New lining swells during break‑in. | H. | Back‑off adjustment until brakes are free. |
CHART 4 - TROUBLESHOOTING SYMPTOM/CAUSE/REMEDY
8 | BW7499 © 2011 Bendix Commercial Vehicle Systems LLC. All Rights Reserved. 03/11 Printed in U.S.A. |