BENDIX SD-05-4630 Symptom Cause Remedy, Slack adjusters should, Not be manually, Brake components

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 drum—worn, excessively	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.
2.	Brakes dragging —	A.	Versajust slack adjuster improperly	A.	Correct the Versajust slack adjuster
	apparent over-adjustment		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.
		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.