Understanding Cummins Maintenance Levels: What to Expect at Level 1, 2, and 3

Cummins engines are built for durability, but like any high-performance equipment, they require structured maintenance. The company recommends a tiered service approach: Level 1, Level 2, and Level 3 Maintenance. Each level defines how frequently certain parts must be inspected and replaced.

Level 1: Routine Care

Performed most frequently, Level 1 maintenance is about keeping the engine’s daily operation smooth. Operators or fleet mechanics usually handle this stage.

Includes:

• Oil change and oil filter replacement
• Checking coolant levels and condition
• Inspecting belts, hoses, and connections
• Monitoring dashboard fault codes

Replaced parts: Oil filter, engine oil

Level 2: Preventive Maintenance

Level 2 is carried out less often, typically every 500–1,000 hours of use. It is preventive in nature and ensures major components remain in good condition.

Includes:

• All Level 1 services
• Fuel filter replacement
• Crankcase ventilation filter replacement
• Detailed inspection of electrical systems

Replaced parts: Oil filter, fuel filter, crankcase filter

Level 3: Major Service

Level 3 is usually performed annually or every 2,000–4,000 hours. It involves comprehensive inspection and replacement of critical components, often by Cummins-certified service centers.

Includes:

• All Level 1 and 2 services
• Coolant replacement and coolant filter change
• Air filter replacement
• Injector inspection/replacement
• Valve lash adjustment
• Alternatorand starter inspection

Replaced parts: Coolant filter, coolant, air filter, injectors (if required), belts

Final Thoughts

Understanding the difference between Level 1, 2, and 3 Maintenance helps equipment owners plan service costs and avoid unexpected downtime. From simple oil changes to complete injector servicing, Cummins’ structured maintenance ensures that your engine delivers maximum uptime and productivity.