Haldex S-ABA User manual

Service
Manual
S-ABA (Self Setting Automatic
Brake Adjusters)
Truck and Trailer Applications

Warning: Haldex strongly recommends routine visual checks be performed at EACH
maintenance service interval. Foundation brake operational checks utilizing CVSA
Level 1 Applied Stroke Criteria should always be utilized. Manual adjustment of
within the foundation brake. Brake components such as s-cams, bushings, return
springs, actuators, drums and adjuster installation MUST be within manufacturer’s
specifications. Adjuster control arms, wear bushings or attaching hardware that
demonstrate visual damage, or which fail the operational checks, MUST be replaced
immediately. Automatic adjusters should NEVER be operated as manual adjusters
except as may be necessary to get the vehicle off the road for service.

S-ABA Operation................................... 1
S-ABA Brake Adjuster Identification ... 1
Steer Axle Applications ........................ 2
Drive Axle Applications ........................ 2
Trailer Axle Applications ...................... 3
S-ABA Installation Procedures ............. 4
Routine Visual/Operational Checks...... 6
Service and Lubrication Intervals ......... 6
Foundation Brake Operational
Check and Troubleshooting.................. 7
Brake Adjuster Checking Procedures .. 9
Brake Adjuster Operational Check....... 9
Typical Parts Identification
and Location ....................................... 10
Torque Specifications .......................... 11
Frequently Asked Questions............... 12
Additional Parts and
Service Information............................. 13
Important Notice
This symbol is used throughout this manual to
call attention to procedures where carelessness
or failure to follow specific instructions may
result in personal injury and/or component
damage.
The descriptions and specifications contained in this service
publication are current at the time of printing. Haldex Brake
Products Corp. reserves the right to discontinue or modify
its models and/or procedures and to change specifications
at any time without notice.
Table of Contents

Brake Adjuster Identification
Control Disc
Coil Spring
Wormshaft
Heat
Treated
Housing
Worm Wheel
Clutch Wheel
Regulator Gear
Adjustment Hex
One-Way
Clutch
The Part No.
P/N40920002
would be
our adjuster
part number
409-20002.
The Haldex S-ABA automatic brake adjuster is a clearance sensing brake adjuster
that maintains a nominal distance or clearance between lining and drum.
When the Adjuster is
Installed:
With the brake in the released
position, the control arm is
fixed to the anchor bracket.
The adjustment hex is rotat-
ed until the shoes contact the
brake drum and then backed
off 1/2 turn. When the brake is
applied on the first application,
the endless rack rotates to the
correct position and sets itself.
When the Brake Applies:
When the brake is applied, the
adjustment regulator rotates
through the normal clearance
angle and the shoes contact
the drum. The torque increases
and the wormshaft is moved
axially, causing the coil spring
to be compressed and the
clutch wheel to disengage.
The adjustment components
are free to rotate as the brake
continues to apply.
Part Number:
409-20_ _ _ = S-ABA Brake Adjuster
Serial Number:
First 3 digits = Day of year built
Last 2 digits = Year of build
1
When the Brake Releases:
When the brake is released, the torque decreases
returning the wormshaft to the clutch wheel and
re-engaging the teeth. The adjustment regulator rotates
through the normal clearance angle and the brake is
released. If lining wear has taken place the adjustment
regulator advances the clutch wheel reducing the excess
clearance during the release stroke.
S-ABA Identification
S-ABA Operation
Part Number
40920002
Serial Number
26802

Steer Axle
Figures 1 and 2 show
typical brackets for
automatic brake adjuster
applications on steer axle
brake assemblies. Refer to
pages 4 and 5 for detailed
installation procedures.
Drive Axle
Figures 3 and 4 show
typical brackets for
automatic brake adjuster
applications on drive axle
brake assemblies. Refer to
pages 4 and 5 for detailed
installation procedures.
Figure 1
Steer axle with clamp bracket
and flat anchor stud
Figure 3
34°drive axle with strap
bracket
Figure 2
Steer axle with strap bracket
Figure 4
Mack drive axle with clamp
bracket and flat anchor stud
Note: Refer to fundamental parts identification and location on page 10. 2
Typical Applications

Trailer Axle
Figures 5-8 show typical brackets for automatic brake adjuster applications
on trailer axle brake assemblies. Refer to pages 4 and 5 for detailed
installation procedures.
3
Figure 5
For 16-1/2” Brake Assemblies
Note: Refer to fundamental parts identification and location on page 10.
Typical Applications
Figure 7
Integral cam support anchor bracket
for 12 1/4” and 15 1/2” brakes
Figure 8
Bolt-on cam support anchor bracket
for 12 1/4” and 16 1/2” brakes
Figure 6
For 12-1/4” Brake Assemblies

Note: Configuration of anchor bracket and brake adjuster housing may vary, depending
upon axle. Refer to typical applications on Pages 2 and 3.
Note: Block wheels to prevent
vehicle from rolling. Ensure system
tank pressure is above 100 PSI.
Check that the push rod is fully retracted;
apply air to release spring brake. If air is not
available, spring brake must be manually
caged back.
Install anchor bracket loosely as illustrated
(Figure 9).
Some strap brackets have two mounting
holes. Proper mounting location is
determined by the length of adjuster arm.
5” and 5 1/2” adjuster arm lengths utilize
the shorter hole location while 6” and 6 1/2”
length adjusters utilize the longer hole
locations.
Do not tighten anchor bracket fasteners at
this time.
Apply “Anti-Seize” type lubricant to
camshaft splines.
Install the brake adjuster onto the camshaft
with the adjusting hex pointing away from
the brake chamber (Figure 10).
Secure the brake adjuster on the camshaft.
Use at least one inner washer and enough
outer washers to allow no more than .060
movement of adjuster on camshaft. (Per
TMC recommended practice RP609-A.)
Note: Do NOT pull push rod out to
meet the brake adjuster.
Rotate the 7/16” adjusting hex nut
CLOCKWISE until the clevis hole lines up
with the brake adjuster arm hole.
Apply anti-seize to clevis pin, install and
secure with cotter pin. 4
Figure 9
Figure 10
S-ABA Installation Procedures
STEP 1
STEP 2

5
Figure 12
Figure 11a
Figure 11b
Figure 11c
The S-ABA control arm can be placed
anywhere within the range of the bracket
slot for automatic adjustment to take
place. Haldex recommends a “common
position” for all installations, to avoid
confusion for the end-user.
Tighten all anchor bracket fasteners.
The adjuster must be manually adjusted
at this time.
Rotate the adjusting hex clockwise until
the lining lightly contacts the drum.
Back-off the adjuster by turning the
adjusting hex counter-clockwise 1/2 of a
turn (Figure 12).
A minimum of 13 ft. lbs. is necessary to
overcome the internal clutch. A ratcheting
sound will be present.
Note: Do NOT use an impact wrench
or permanent internal damage will
occur!
Note: To ensure proper fit and
function, always replace both
adjuster and mounting bracket,
as a set.
S-ABA Installation Procedures
STEP 3
STEP 4

Haldex strongly recommends that routine visual/operational checks,
including brackets and control arms, be performed at each Preventative
Maintenance Service Interval.
Adjusters or anchor brackets that have visual damage, or which fail
the operational checks, MUST be replaced immediately.
Automatic adjusters should not be operated as manual adjusters except as
may be necessary to get the vehicle off the road for service.
6
Routine Visual / Operational Checks
Service and Lubrication Intervals for
Standard Haldex AA1 and S-ABA Brake Adjusters
Note: No-LubeTM automatic brake adjusters are manufactured without a grease
fitting and are identified by a 429 prefix.
Moly-disulfide grease should not be used because it may affect the function of
the internal friction clutches and reduce the reliability of the automatic
adjustment.
In no case should the lubrication interval exceed the published intervals
shown above.
Adjuster
Type
Manufacture
Date
Lubrication
Interval
Type of
Lubricant
Visual Check
Interval
Standard
Adjuster 409-10...
Prior to 6/1/96 50,000 miles or
every 3 months
Standard Chassis
Grease
Each Preventative
Maintenance
Service Interval
Reduced Maintenance
Adjuster 409-10...
After 6/1/96 Once a year Standard Chassis
Grease
Each Preventative
Maintenance
Service Interval
No-Lube™
Adjuster 429-10...
After 6/1/96 None Sealed Unit Each Preventative
Maintenance
Service Interval
S-ABA
Adjuster 409-20...
n/a Once a year Standard Chassis
Grease
Each Preventative
Maintenance
Service Interval

Component Cause Action
Brake Drums Cracked or out of round Replace or check drum run out
Brake Shoes Shoe span out of spec Refer to OEM specs and replace if necessary
Uneven lining wear Check spider concentricity
Shoe pad missing Remove and replace shoes
Cracked shoes Remove and replace shoes
Camshaft Bushings Excessive movement Remove and replace cam bushings per OEM specs
Camshaft Flat spots on cam head Replace camshaft
Cracked/broken splines Replace camshaft
Worn bearing journals Replace camshaft
Chamber Bracket Broken/bent Replace bracket
Clevis Yoke and Pin Worn Remove and replace
Return Springs Broken/stretched or missing Remove and replace springs
Rollers Flat spots, grooved pin/worn Remove and replace roller and pin
Wrong size Remove and replace with correct parts
Spider Anchor Pins Grooved or scored/worn Replace spider or pins per OEM specs
NOTE: Long stroke chambers are identified with
square air ports or port bosses and special trapezoid
ID tags.
Measuring the Free Stroke
Free stroke is the amount of movement of the adjuster arm required to move the brake shoes
against the drum. With brakes released, measure from the face of the chamber to the center
of the clevis pin “A” (Figure 13). Use a lever to move the brake adjuster until the brake shoes
contact the drum “B” (Figure 13). The difference between the fully retracted and drum contact
measurement “B”–“A” (Figure 13), is the free stroke. The free stroke range should fall between
3/8”–3/4”.
Free Stroke Within The Range
If the free stroke is good, but the applied stroke is too long, there is probably a problem
with the foundation brake. Check the following and reference CVSA out-of-service criteria:
7
Foundation Brake Operational Check/Troubleshooting
Free Stroke
Standard Clamp Type Brake Chamber
Type Adjustment Limit Type Adjustment Limit
9 1-3/8” 24 1-3/4”
12 1-3/8” 30 2”
16 1-3/4” 36 2-1/4”
20 1-3/4”
Long Stroke Type Brake Chamber
Type Adjustment Limit Type Adjustment Limit
16L 2” 24LS 2-1/2”
20L 2” 30LS 2-1/2”
24L 2”
Note: Block wheels to prevent vehicle from rolling.
Ensure system reservoir pressure is at 90-100 psi.
Check that push rod is fully retracted; apply air to release spring brake.
North American Commercial Vehicle Safety Alliance (CVSA) Uniform Vehicle Inspection
Criteria: The applied stroke of the brake should be checked per CVSA guidelines at
90-100 psi reservoir pressure. Applied stroke should be at or less than the specified
readjustment limits as shown below.

Component Cause Action
Air Chamber Pushrod Binding on chamber housing Check adjuster for proper shimming and air
chamber position for proper adjuster arm length
Air Chamber Return Springs Broken, weak, missing Replace chamber
Air System Not exhausting completely Check for cause of air problem and repair
Automatic Brake Adjuster Unknown Check automatic brake adjuster for proper
installation (refer to Pages 4 & 5 and 9 & 10).
Camshaft Binding Remove, replace, lubricate camshaft
Camshaft Bushings Excessive movement Remove and replace cam bushings per OEM specs
Binding shaft Lubricate camshaft bushings or replace
Shoe Return Springs Broken, weak, missing Replace springs
Component Cause Action
Automatic Brake Adjuster Unknown Check automatic brake adjuster for proper
installation (refer to Pages 4 & 5 and 9 & 10).
Wheel Bearing Out of adjustment Readjust wheel bearing per OEM specs
Free Stroke Above The Range
If the free stroke is above the range and the applied stroke is too long, there is a problem with the
foundation brake or the adjuster. Check the following and reference CVSA out-of-service criteria:
Free Stroke Below The Range
If the free stroke is less than 3/8”, a dragging brake can occur. Check the following and reference
CVSA out-of-service criteria:
Free
Stroke = B minus A
A
(Fully Retracted)
B
(Drum Contact Using a Lever)
C
(Brake Application at 90-100 PSI
reservoir pressure.)
Figure 13
Stroke Measurements
(taken from face of air
chamber to center of
clevis pin)
8
Free Stroke (cont’d)

If the brake adjuster is not maintaining the proper applied stroke, before removing
the brake adjuster, check the condition of the foundation brake (see pages 7 & 8). If
after inspecting the foundation brake no apparent problems are found, inspect the
automatic brake adjuster to determine if it is operating properly. The inspection can be
performed on or off the vehicle using the following procedures.
Note: Block wheels to prevent vehicle from rolling. Ensure system reservoir
pressure is at 90-100 PSI.
Check that push rod is fully retracted; apply air to release spring brake.
If air is not available, spring brake must be manually caged back.
Do not use air tools on brake adjuster!
Component Cause Action
Excessive
chamber push
rod travel
Improper anchor If anchor bracket to control arm connection
bracket connection is worn, loose, bent or broken, it must be
to control arm re-secured or replaced.
Low clutch torque Rotate the 7/16” adjustment hex one full
turn counterclockwise. Replace brake
adjuster if the torque is less than 13 ft. lbs.
or no racheting sound occurs.
Unknown Perform automatic brake adjuster
operational check (see below).
Note: Functional operation of the brake adjuster can be performed on the
vehicle by using the following procedure:
Block wheels to prevent vehicle from rolling.
Ensure reservoir pressure is at 90-100 psi.
Check that the push rod is fully retracted; apply air to release spring brake.
If air is not available, spring brake must be manually caged back.
Manually de-adjust brakes (turn adjustment hex counterclockwise one full turn) to create an
excessive lining to drum clearance condition. (A ratcheting sound should occur.)
Make a full service brake application. On release, allow sufficient time for air chamber to fully
retract.
During the brake release, observe rotation of the adjustment hex (attaching a wrench on the hex
or scribing the hex will make this rotation easier to see).
This rotation indicates that an excessive clearance condition has been determined by the brake
adjuster, and it is making an adjustment to compensate. On each subsequent brake release,
the amount of adjustment and push rod travel will be reduced until the desired lining to drum
clearance is achieved.
If rotation of the adjustment hex is not observed, refer to Foundation Brake Operational Check
and Troubleshooting Procedures on Pages 7 & 8. If foundation brake assembly checks out okay and
hex still does not turn, check control arm and mounting bracket for possible worn, bent or broken
components. If the control arm and mounting bracket check out okay, replace the adjuster and
hardware per Installation Instructions on Pages 4 & 5.
9
Automatic Brake Adjuster Checking Procedures
On Vehicle Inspection
Automatic Brake Adjuster Checking Procedures

Anchor
Stud Pin
Anchor
Bracket
Control Arm
(Single Bend)
Wear
Anchor
Bracket
Anchor
Stud Pin
Wear
Adjustment
Hex Nut
Control Arm
Component Cause Action
Adjuster not
functioning
properly
Low clutch Place adjuster arm in vise. Rotate the 7/16”
torque adjustment hex counterclockwise one full turn to
check de-adjustment torque. After control arm
stops rotating, a minimum of 13 ft. lbs. will be
required and a ratcheting sound will occur.
Replace brake adjuster if the torque is
less than 13 ft. lbs. or no de-adjustment racheting
sound is present.
Control Arm Place adjuster arm in vise. Rotate the control arm
slippage clockwise and counterclockwise while observing
the internal sleeve. If slippage between the
control arm and the internal sleeve is observed,
replace the brake adjuster.
Unknown If torque is above 13 ft. lbs., scribe a line on the
adjustment hex. Manually pull the brake
adjuster control arm clockwise then push back
counter-clockwise. The hex will move in a
clockwise direction when the control arm of the
brake adjuster is pushed back counterclockwise.
Replace adjuster if hex does not move.
Worn/missing Remove and replace pin and bushings. If
control arm wear adjuster has passed the above checks, re-install
bushing, and on vehicle, with new hardware.
anchor stud pin,
if applicable
Bushing Bushing
10
Off Vehicle Inspection
Typical Parts Identification and Location

Round Anchor
Stud Pin with
Fabricated
Ring Clamp
Torque to 15-20
ft. lbs. when
installed
3/8”-16 Nut
and Bolt
Flat Anchor
Stud Pin
Torque to
40-50 ft. lbs.
when installed
Round Anchor Stud
Pin with Slide Nut
Torque to 15-20 ft. lbs.
when installed
Strap Style
Bracket
Torque to
8-12 ft. lbs.
when installed
U-Bolt Style
Bracket
Torque to 20-
30 ft. lbs. when
installed
Note: Tighten all fasteners to manufacturer’s recommendations
unless otherwise specified below.
11
Torque to 15-20 ft.
lbs. when installed
Torque Specifications

12
Frequently Asked Questions
1. Will the side of the brake adjuster with
the face plate always face in?
No. Haldex adjusters are normally unhanded.
Always install with the adjusting hex pointing
away from the air chamber.
2. Why is there resistance when backing
off the adjuster?
It takes approximately 20-25 lb. ft. of torque to
back off the adjustment hex on a new brake
adjuster. (A ratcheting sound should occur.)
3. How far do I back off the automatic
brake adjuster at a brake reline?
1/2 turn. (NOTE: for the first 1/8 turn you may
not hear the ratcheting; this is normal.)
4. How do I know if I need an offset,
angled or straight-armed adjuster?
Haldex manufactures the right adjuster arm for
your specific application. Haldex adjusters are
unhanded (no lefts or rights) in the majority of
applications. Please refer to the Haldex Parts
and Cross Reference Guide for your specific
application (L00090).
5. Why does my replacement ABA look
different from the original I removed?
The Haldex ABA replacement adjuster has been
designed to fit a number of applications. It is the
same original equipment quality and design of
the adjuster you removed; however, it may look
different on the outside. If you use all the parts
included in the kit, the results will be the same
as the original equipment adjuster.
6. Why is the applied stroke pressure
tange 90-100 psi at the reservoir?
This is the pressure recommended by thE
Commercial Vehicle Safety Alliance (CVSA).
Anything beyond 100 psi measure deflection
within the foundation brake and not true
pushrod stroke.
7. Some brake chambers have round
port openings and some square;
what is the difference?
Standard brake chambers are identified by round
ports. Long stroke chambers are identified by
square ports and trapeziod ID tags.
8. Can I vary the amount of
lining-to-drum clearance by moving
the control arm?
No. That clearance is set at the factory. If long
or short stroke continues, please refer to the
Foundation Brake Checking Procedures on pages
9 & 10 of this manual.
9. Can I use an air ratchet on the
adjuster?
No. It will damage the internal mechanism of the
adjuster and render it inoperative.
10. Can I access the adjuster through the
rear cover?
No. Do not tamper with the rear cover - it will
release the factory set pressure on the spring and
destroy the adjuster and its ability to properly
function.
11. How much control arm bushing
and anchor stud pin wear is
acceptable before replacement is
required?
No more than 1/16”.
12. What is the acceptable amount of
camshaft bushing wear?
Automatic adjuster cannot compensate for
worn foundation brake parts. Please refer to
the foundation brake manufacturer’s
recommendations for maximum bushing and
camshaft wear limits.
13. Can wheel bearing adjustment
affect the brake adjuster?
Yes. Improper wheel bearing adjustment could
result in improper brake adjustment. It is
necessary to refer to the axle manufacturer’s
wheel bearing adjustment recommendations. A
loose bearin preload could cause a tight brake.
14. Are all Haldex automatic brake
adjusters pre-lubed?
Yes. All Haldex brake adjuster are lubricated
at the factory. Please consult the Service and
Lubrication Section on Page 6 of the manual.
(continued on page 13)

13
Frequently Asked Questions (cont’d)
Additional Information Available
15. Can I use moly lube with the Haldex
automatic brake adjuster?
No. A high concentration of moly-disulfide can
lower the friction capabilities in the adjusting
clutch parts and decrease automatic adjustment
reliability.
16. Can I purchase anchor bracket wear
items separately (ie. anchor stud pins,
wear bushings)?
Yes. Normal wear items like anchor stud pins
and wear bushings are available. Refer to the
Haldex Parts and Cross Reference Guide
L00090. Otherwise, contact Haldex Technical
Assistance for the appropriate bracket kit at
1-800-643-2374.
Additional parts and service information on Haldex Automatic Brake Adjusters may be
found in the following materials:
Service Information
Installation and Maintenance Wall Chart ..................................................................L60047
Service Manual (Truck/Trailer) ......................................................................................L30037
Installation Tips — Automatic Brake Adjuster (Pocket Size)......................................L20397
Parts Information
Parts and Cross Reference Guide (Truck/Trailer) ........................................................L00090
Supplemental Automatic Brake Adjuster Kits ...........................................................L20447
These materials are readily available on the Haldex website haldex.com, or you may
order copies by contacting your Customer Service Representative at 1-800-643-2374.
17. Does the control arm need to be
properly set and secured?
Yes. Without proper placement and attachment,
the adjuster will not function properly. Make
sure the control arm, anchor bracket and wear
items are in good working order to assure the
adjuster will operate as designed.
18. If automatic adjustment stops, can
I operate as a manual brake adjuster?
No. Completely check out foundation brake and
adjuster to determine cause of problem. Repair
or replace as needed to restore automatic
adjustment.

14
Notes:

15
Notes:

Haldex develops and provides reliable and
innovative solutions with focus on brake
and air suspension products to the global
commercial vehicle industry.
Listed on the Stockholm Stock Exchange,
Haldex has annual sales of approximately 3.9
billion SEK and employs about 2,200 people.
United States 816-891-2470
Canada 519-621-6722
Mexico 52-81-81569500
To learn more, contact your Haldex sales professional.
L30037
US Rev. 3/18 2.5M ALP
Printed In The USA
For additional contact information
or to learn more about Haldex,
please visit Haldex.com