Premium wheel-end brake products Service Manual Spicer® Automatic Slack Adjuster
Self Adjusting Brake Adjuster The description and specifications contained in this service publication are current at the time of printing. Bendix Spicer Foundation Brake LLC reserves the right to discontinue or modify its models and/or procedures and to change specifications at any time without notice. Any reference to brand name in this publication is made as an example of the types of tools and materials recommended for use and should not be considered an endorsement. Equivalents may be used.
Self Adjusting Brake Adjuster Contents Important Notice ............................................................................... 1 Introduction ...................................................................................... 3 Operation ........................................................................................... 3 Self Adjusting Brake Adjuster Identification ................................ 4 Steer Axle Installations ...............................................................
Introduction/Operation Introduction Spicer® brand self adjusting brake adjusters compensate for wear in brake shoe linings caused by normal braking operation. Upon brake application, the brake adjuster assembly rotates, rotating the brake camshaft. The camshaft moves the shoes into contact with the drum. During brake application and release, the adjuster mechanism rotates the camshaft slightly to maintain the correct shoe-todrum clearance.
Introduction/Operation Self Adjusting Brake Adjuster Identification 68 8081 MFD 25 BY . IN HAL U.S DEX .A. 4W F 1A 107 The serial and part numbers are stamped on the facing of the self adjusting brake adjuster. The serial number is used for control purposes. The part number describes the self adjusting brake adjuster specification. 100 MANUFACTURER NUMBERS 1A107 4WF 10068 MFD. IN U.S.A.
Typical Applications Steer Axle Installations Figures 2, 3, 4 and 5 show typical brackets for self adjusting brake adjuster installations on steer axles: • Straight brake adjuster using a clamp-type bracket (See Figure 2.) • Offset brake adjuster using clamp-type bracket (See Figure 3.) • Offset brake adjuster using bolt-on type bracket (See Figure 4.) • Disc brake type installation (See Figure 5.) Refer to pages 9, 10 and 11 for detailed installation procedures.
Typical Applications Drive Axle Installations Figures 6, 7, 8 and 9 show typical brackets for self adjusting brake adjuster installations on drive axle brakes: • Straight brake adjuster using a clamp-type bracket (See Figure 6.) • Offset brake adjuster using bolt-on bracket (See Figure 7.) • Straight brake adjuster using bolt-on type bracket (See Figure 8.) • Disc brake application (See Figure 9.) Refer to pages 9, 10 and 11 for detailed installation procedures. TORQUE TO 8-12 FT. LBS. TORQUE TO 40-50 FT.
Typical Applications Trailer Axle Installations BOLT-ON BRACKET Figures 10 through 13 show typical and alternative brackets for self adjusting brake adjuster installations on trailer installations. SELF ADJUSTING AUTOMATIC BRAKE SLACK ADJUSTER Universal Anchor Bracket Tip: The universal anchor bracket mounts to the “S” cam bushing support bracket. Rockwell, Dana and Fruehauf brakes mount with two bolts. Position plate on adjuster side of the “S” cam support.
Anchor Stud Installation STEP ONE SNAP BUSHING SECURELY INTO PLACE STEP TWO STEP THREE 2ND TILT STUD AS SHOWN TO INSTALL 1ST SECURE STUD WITH FLANGE HEAD NUT ROTATE TO INTERNAL STOP ALIGN ARROW WITH SLOT AX05 8 Figure 13 Anchor Stud Installation
Installation Installation Procedure Caution: The procedures shown in this section are applicable to vehicles originally equipped with Spicer® brand self adjusting brake adjusters only, and must not be used for aftermarket retrofit. Specific retrofit instructions are provided with retrofit kits. ANCHOR BRACKET CAMSHAFT Attach the Self Adjusting Brake Adjuster WARNING: BLOCK WHEELS TO PREVENT VEHICLE FROM ROLLING. CAGE SPRING BRAKES IF INSTALLED.
Installation Position the Control Arm ROTATE TO STOP 6. Rotate the control arm counterclockwise away from adjustment hex towards the air chamber until it comes to a definite internal stop. (See Figure 16.) If necessary, use a plastic mallet to tap the control arm into position. Caution: Excessive positioning force may damage the control arm. Most adjusters will be equipped with an Installation Indicator. Indicator must fall within the slot for proper installation.
Installation Applied Stroke Adjustment Adjust the Self Adjusting Brake Adjuster 1. Apply and hold an 80-90 psi brake application. Free Stroke Adjustment 2. Measure distance between face of air chamber and clevis pin centerline. Record distance as dimension C. 1. With air chamber fully retracted, measure distance from face of air chamber to centerline of clevis pin. Record exact measurement as dimension A. 3. Subtract dimension A from dimension C. The difference is applied stroke.
Maintenance Brake Adjuster Maintenance–General Service Intervals Component Lubrication Interval Type of Lubricant Adjusters manufactured prior to 6/1/96 – every 50,000 miles or every 3 months. Adjusters manufactured after 6/1/96 – once a year. Standard Chassis Grease Once a year SHC 460 Synthetic None *Lubricated at Factory Visual Inspection Standard During normal chassis lubrication or 3 months which ever occures first.
Operational Check/Troubleshooting Operational Check Troubleshooting 1. Measure the pushrod length (distance from the face of air chamber to the centerline of the pushrod clevis pin) when fully retracted, step 1. (See Figure 20.) 2. Have an assistant make an 80 to 90 psi brake application. Measure pushrod length again, step 2. 3. Subtract the step 1 dimension from step 2. The difference is the “applied stroke.” 4. Verify that the applied stroke is less than the maximum specified below.
Additional Service Information Additional parts and service information on these and related Bendix Spicer Foundation Brake products may be found in the following publications: Service Manuals • 15" x 4" Steer Axle Brakes (Models ES-150 and EB-150) ...........................................................................................................BW7258 • 16.5" and 18" Axle Brakes (Models ES-165, EB-165 and EB-180) ....................................................................................
For more information, talk to your Bendix or Roadranger representative, call 1-866-610-9709 or visit www.foundationbrakes.com. Spicer® is a registered trademark of Dana Corporation 901 Cleveland Street • Elyria, Ohio 44035 • 1-866-610-9709 • www.foundationbrakes.com BW7257 ©2006 Bendix Spicer Foundation Brake LLC • 09/06 • All Rights Reserved • Printed in U.S.A. The Roadranger® System features Bendix® brand foundation brakes.
