THE SECOND COMING OF AUTOMATIC SLACK ADJUSTERS

The manufacture, construction, and fleet use of automatic brake slack adjusters are considered. Only three companies manufacture the adjusters (Bendix, Borg and Beck, and Rockwell), and the operating principle is similar for all makes. All adjusters incorporate some type of clutch spring and a worm gear which rotates the "S" camshaft. These are sealed to prevent contamination by dirt and water, one of the major problems with earlier models. Manufacturers recommend visual inspections at 25,000 miles and lubrication at 50,000 miles. The primary market for adjusters is as original equipment. Fleet and industry attitudes represent the biggest factor in the success or failure of adjusters. Design modifications have been made, and proponents indicate that maintenance time and cost per unit for brake systems are decreased when using automatic slacks, although no carrier has reported longer brake lining life. The National Hwy. Traffic Safety Administration had planned to issue an advanced notice of proposed rulemaking in 1979 dealing with automatic slack adjusters, antilock systems, and engine and driveline retarders. Alternatives that may affect the use of automatic brake slack adjusters are air-actuated disc brakes and the Camph brake mechanism devised by Midland-Ross, in which the braking and adjusting mechanisms are integrated. Midland-Ross is expected to concentrate on the transit market where overall costs of brakes and liners are high and the Camph mechanism can provide better cost benefits than automatic slack adjusters.

• Corporate Authors:

  Chilton Company, Incorporated

  One Chilton Way
  Philadelphia, PA  United States  19089
• Authors:
  • Galligan, J
• Publication Date: 1980-7

Media Info

• Pagination: p. 47-52
• Serial:
  • OWNER OPERATOR
  • Volume: 10
  • Issue Number: 4
  • Publisher: MALMGREN TRUCKING.

Subject/Index Terms

• TRT Terms: Antilock brake systems; Automation; Brake linings; Brakes; Disc brakes; Inspection; Vehicle maintenance; Vision
• Old TRIS Terms: Antilocking devices; Slack adjusters
• Subject Areas: Maintenance and Preservation; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 00376828
• Record Type: Publication
• Source Agency: National Highway Traffic Safety Administration
• Report/Paper Numbers: HS-030 056
• Files: HSL, USDOT
• Created Date: Jul 30 1983 12:00AM