Class B / C / D Preventive PM Checklists

Comprehensive preventive maintenance checklists for Class B, C, and D commercial vehicles to ensure optimal performance and prevent costly breakdowns.

Class B (26,001+ lbs) Class C (Large Trucks) Class D (Buses)
Recommended Intervals: Every 3,000-6,000 miles or 90 days, whichever comes first

Engine & Powertrain Systems

  • Check engine oil level and condition, change if due per maintenance schedule
  • Inspect air filter condition and replace if dirty or clogged
  • Verify coolant level and inspect for leaks in radiator and hoses
  • Test engine temperature gauge and warning lights operation
  • Check transmission fluid level and color (should be red/pink, not brown/black)
  • Inspect drive belts for cracking, fraying, or improper tension
  • Verify proper operation of cooling fan and shroud condition
  • Check turbocharger (if equipped) for proper boost pressure
  • Inspect exhaust system for leaks, damage, or excessive corrosion
  • Test engine block heater operation (if equipped)

Brake System Inspection

  • Check brake fluid level and color (should be clear, not dark/contaminated)
  • Inspect brake pads/shoes for thickness and even wear patterns
  • Examine brake rotors/drums for scoring, cracking, or excessive wear
  • Test service brake pedal travel and firmness
  • Verify parking brake adjustment and holding capability
  • Check air brake system pressure (if equipped) - should build to 120 PSI
  • Inspect brake hoses and lines for leaks, cracks, or chafing
  • Test ABS warning light operation and system function
  • Verify brake chamber and slack adjuster operation (air brakes)
  • Check brake booster operation (vacuum or hydraulic assist)

Steering & Suspension

  • Check power steering fluid level and condition
  • Inspect steering linkage for wear, damage, or excessive play
  • Verify proper wheel alignment and tire wear patterns
  • Test steering wheel play (should be less than 2 inches)
  • Inspect shock absorbers/struts for leaks or damage
  • Check suspension components for worn bushings or ball joints
  • Verify proper operation of air suspension system (if equipped)
  • Inspect leaf springs or coil springs for damage or sagging
  • Check stabilizer bar links and bushings
  • Test front-end alignment and steering return-to-center

Tires & Wheels

  • Check tire pressure on all tires including spare (use proper PSI rating)
  • Inspect tire tread depth using penny test or tread depth gauge
  • Look for uneven wear patterns indicating alignment or suspension issues
  • Check for sidewall damage, cuts, bulges, or embedded objects
  • Verify proper tire rotation per manufacturer recommendations
  • Inspect wheel lug nuts for proper torque and condition
  • Check wheel rims for cracks, bends, or corrosion
  • Verify tire pressure monitoring system (TPMS) operation
  • Inspect valve stems and caps for damage or leaks
  • Document tire serial numbers and remaining tread life

Electrical System

  • Test battery voltage and specific gravity (should be 12.6V or higher)
  • Clean battery terminals and check cable connections
  • Inspect alternator belt tension and charging system operation
  • Check all exterior lights: headlights, taillights, turn signals, hazards
  • Test horn operation and adjust if necessary
  • Verify proper operation of dashboard warning lights
  • Check wiper motor operation and blade condition
  • Test backup alarm and warning devices (commercial vehicles)
  • Inspect wiring harnesses for damage, chafing, or loose connections
  • Verify proper operation of electronic control modules

HVAC & Interior Systems

  • Test heating and air conditioning system operation
  • Replace cabin air filter if dirty or per maintenance schedule
  • Check HVAC controls and temperature regulation
  • Inspect seat condition and adjustment mechanisms
  • Verify safety belt operation and condition
  • Test all interior lights and switches
  • Check rearview mirrors and adjust as needed
  • Inspect windshield for chips, cracks, or visibility issues
  • Test radio/communication equipment operation (if equipped)
  • Verify fire extinguisher presence and charge level

Fuel System & Emissions

  • Check fuel level and inspect fuel tank for leaks or damage
  • Replace fuel filter per manufacturer maintenance schedule
  • Inspect fuel lines and connections for leaks or deterioration
  • Check fuel cap seal and proper closure
  • Verify proper operation of fuel gauge and low fuel warning
  • Inspect diesel exhaust fluid (DEF) level (diesel engines)
  • Check emission control systems and warning lights
  • Inspect catalytic converter and exhaust after-treatment
  • Verify proper operation of fuel pump and pressure
  • Document fuel consumption patterns for efficiency monitoring

Safety & Compliance Checks

  • Verify current vehicle registration and inspection certificates
  • Check first aid kit contents and expiration dates
  • Inspect emergency equipment: triangles, flares, fire extinguisher
  • Verify proper DOT markings and placards (commercial vehicles)
  • Check driver's daily vehicle inspection report (DVIR) compliance
  • Inspect mud flaps and splash guards for damage
  • Verify proper operation of backup cameras/sensors (if equipped)
  • Check load securement equipment and tie-down points
  • Inspect steps, handholds, and entry/exit safety features
  • Document any safety concerns or recommended repairs
Use Checklist Online