24,000-Mile PM Procedure – Truck & Trailer Maintenance

Detailed Service Procedures

Follow these structured procedures for critical maintenance tasks at the 24,000-mile service interval. These detailed steps help ensure consistent quality and thoroughness for essential service operations.

Brake Inspection & Adjustment Procedure

  • Secure vehicle and release spring brakes
  • Remove dust shields (if equipped) for proper inspection
  • Measure brake lining thickness at thinnest point
  • Inspect drums/rotors for cracks, heat checking, or grooves
  • Check for proper drum-to-lining clearance
  • Verify proper slack adjuster stroke (3/4" to 1" at 90 psi)
  • Adjust brakes if necessary according to manufacturer specs
  • Reinstall dust shields and components
  • Perform brake application test and verify equal braking

Fifth Wheel Service

  • Inspect for cracks in fifth wheel plate and mounting brackets
  • Clean fifth wheel plate of all old grease and debris
  • Check jaw/lock operation for complete engagement
  • Verify proper release handle operation and adjustment
  • Inspect mounting bolts for proper torque
  • Measure and verify kingpin locking range
  • Apply proper fifth wheel grease to plate surface
  • Check slider rail operation and locking pins (if equipped)

Air System Maintenance

  • Drain all air tanks completely
  • Inspect air dryer and replace desiccant cartridge if needed
  • Check air compressor discharge line for carbon buildup
  • Test air pressure build-up time (85-100 PSI in under 3 minutes)
  • Verify low pressure warning system activates at 60 PSI
  • Check for air leaks throughout system
  • Test spring brake automatic application
  • Inspect gladhand seals and replace if damaged

Kingpin and Upper Coupler Inspection

  • Clean kingpin and upper coupler plate thoroughly
  • Measure kingpin diameter with proper gauge
  • Inspect kingpin for cracks, gouges, or deformation
  • Check upper coupler plate for cracks or warping
  • Verify proper upper coupler mounting to trailer frame
  • Inspect reinforcement webbing for damage
  • Test kingpin with fifth wheel locking test
  • Document wear measurements for future reference

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