User manual BENDIX ASA-5 AUTOMATIC SLACK ADJUSTER

[. . . ] ® Bendix® ASA-5TM Automatic Slack Adjuster DESCRIPTION The Bendix ASA-5 automatic slack adjuster is designed for use on cam actuated drum brakes of the type in use on most highway vehicles. Like a manual slack adjuster, the ASA-5TM slack adjuster multiplies and transforms the linear force of the air actuator into a rotational force or torque which is used to apply the foundation brake. Additionally, the ASA-5TM slack adjuster automatically adjusts the clearance between the brake lining and drum to compensate for wear. A variety of ASA-5TM slack adjuster configurations are offered including both straight arm and 5/8" yoke offset models. [. . . ] Experience is a valuable guide in determining the best maintenance interval for air brake system components. At a minimum, the ASA-5TM slack adjuster should be inspected every 3 months or 500 operating hours, whichever comes first, for proper operation. Should the ASA-5TM slack adjuster not meet the elements of the operational tests noted in this document, further investigation and service of the adjuster may be required. Visually check for physical damage such as broken air lines and broken or missing parts. LONG STROKE Brake Actuator Size 30LS 24L 24LS 20L 16L Recommended Maximum Operating Stroke 2-1/2" 2" 2-1/2" 2" 2" 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 the following actuator stroke tables. The correct pressure for this test can be achieved as follows: Build the system pressure up to 100 psi reading on the vehicle gauge. 5 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. ADJUSTER HEX ROTATES CLOCKWISE DURING ADJUSTMENT WARNING: Manual adjustment of automatic slack adjusters is a dangerous practice that could have serious consequences, 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 again. 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. STRAIGHT LINE SCRIBED ACROSS HEX AND BODY TESTING THE ASA-5TM ADJUSTER MECHANISM FIGURE 7 - TESTING ADJUSTER MECHANISM The following test can be made to determine if the ASA-5TM adjuster mechanism is functioning properly. With the brakes released and the vehicle wheels blocked, de-adjust the brakes by rotating the manual adjustment hex counterclockwise approximately 1/2 to 1 revolution. Note: Considerable torque is required to rotate the manual adjustment hex counterclockwise and should be considered normal. The required torque may be as high as 70 foot pounds. Using a straight edge, scribe a line across the manual adjustment hex head and slack adjuster body. Apply and COMPLETELY RELEASE the service brakes several times while observing the manual adjustment hex and the scribed line. The ASA-5TM slack adjuster manual adjustment hex should rotate clockwise during the application and remain stationary during release. No counterclockwise rotation of the hex should be observed. The amount of clockwise rotation (adjustment) will decrease progressively as the brake nears proper adjustment. If the ASA-5 TM slack adjuster fails to perform as described, it will be necessary to repair or replace it. Manually readjust the ASA-5TM slack adjuster being tested before returning the vehicle to service. [. . . ] ASA-5TM adjuster mechanism not functioning. Brake drum--worn, excessively machined, bell-mouthed, excessive thermal expansion. ASA-5TM slack adjuster improperly installed. Reposition components and torque to specification. [. . . ]