48,000-Mile Fleet Maintenance Guide

Essential PM Schedule D Service Checkpoints

Detailed Service Procedures

Follow these structured procedures for critical maintenance tasks at the 48,000-mile service interval. These detailed steps help ensure consistent quality and thoroughness for essential service operations.

Transmission Fluid Change Procedure

  • Run transmission to normal operating temperature
  • Position vehicle on lift and secure appropriately
  • Remove transmission pan and clean thoroughly
  • Replace transmission filter and gasket
  • Reinstall pan with new gasket and torque to spec
  • Add manufacturer-specified transmission fluid
  • Start engine and check for leaks
  • Verify fluid level is correct with transmission at operating temperature

Brake System Service

  • Remove wheels and visually inspect all brake components
  • Measure brake pad and rotor thickness with proper gauges
  • Inspect calipers for leakage and proper movement
  • Flush old brake fluid and replace with DOT-specified fluid
  • Bleed brake system to remove all air
  • Check brake pedal feel and travel specifications
  • Test brake function at low speed before returning to service
  • Document measurements and component conditions

Cooling System Service

  • Ensure engine is cool before beginning
  • Remove radiator cap and open all drain points
  • Collect and properly dispose of old coolant
  • Flush system with manufacturer-approved cleaner if necessary
  • Close all drain points and refill with correct coolant/water mixture
  • Bleed cooling system of air per manufacturer procedure
  • Pressure test system to check for leaks
  • Run engine to normal operating temperature and recheck coolant level

Timing Belt Inspection/Replacement

  • Refer to manufacturer service guidelines for specific procedure
  • Remove necessary components to access timing belt
  • Verify timing marks before removing old belt
  • Inspect water pump and replace if recommended at this interval
  • Replace timing belt tensioners and idler pulleys
  • Install new timing belt and verify proper alignment with timing marks
  • Reinstall all components and torque to specifications
  • Test engine operation and check for unusual noises

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