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Operation Tips

It is best to operate your CELECT-equipped Cummins engine at speeds between 1450 and 1550 rpm.

Cummins M11 and N14 engines should operate with coolant temperatures between 158°F and 212°F.

Whenever an engine has been inoperative for more than 30 days, Cummins recommends disconnecting the wire to the fuel shut-off valve and cranking the engine until oil pressure registers on the gauge before starting the engine. This practice will prevent "dry starts" and allow oil to bearings and shafts prior to starting the engine. A toggle switch can be wired into the starting system for this.

Never operate your engine beyond high idle speed under any circumstances. When descending a steep grade, use a combination of transmission gears and engine or service brakes to control the vehicle and engine speed to less than governed rpm. Failure to do this can cause engine damage.

Allow the engine to idle 3 to 5 minutes before shutting it off after a full load operation. This allows the lubrication oil and coolant to carry heat away from the combustion chamber, bearings, shafts and turbocharger and helps prevent carboning the engine oil.

Maintenance Schedule- B and C Series Midrange Engines

Daily or Re-fueling:
Check:

  • Operator Report
  • Drain water and sediment from fuel-water separator
  • Oil Level
  • Coolant Level
  • Engine for oil leaks, coolant leaks, leaks to the air intake system, and damage to belts and hoses
  • Drive Belt

Every 250 hours, 3 months, 6,000 miles or 10,000 km:
Replace:

  • Lube Oil
  • Lube Filter
  • Drain water and sediment from fuel tank(s)

Inspect:

  • Air Cleaner Restriction
  • Air Intake System

Every 500 hours, 6 months, 12,000 miles or 19,000 km:
Replace:

  • Lube Oil
  • Lube Filter
  • Fuel Filter
  • Coolant Filter (C Series only)
  • Drain water and sediment from fuel tank(s)

Inspect:

  • Air Cleaner
  • Air Intake System
  • Antifreeze Freeze Point

Every 1,000 hours, 12 months, 24,000 miles or 38,000 km:
Replace:

  • Lube Oil
  • Lube Filter
  • Fuel Filter
  • Coolant Filter (C Series only)
  • Adjust Valve Lash Clearance
  • Drain water and sediment from fuel tank(s)

Inspect:

  • Air Cleaner
  • Air Intake System
  • Antifreeze
  • Fan Hub
  • Belt Tensioner Bearing
  • Belt Tension
  • Charge Air Cooler

Every 2,000 hours, 2 years, 48,000 miles or 77,000 km:
Replace:

  • Lube Oil
  • Lube Filter
  • Fuel Filter
  • Coolant Filter (C Series only)
  • Belt Tensioner Bearing
  • Adjust Valve Lash
  • Antifreeze
  • Drain water and sediment from fuel tank(s)

Inspect:

  • Air Cleaner
  • Air Intake System
  • Antifreeze
  • Fan Hub
  • Belt Tension Clearance
  • Charge Air Cooler
  • Vibration Damper

Maintenance Tips

Cummins recommends using Fleetguard® LF3000 oil filters for L10, M11 and N14 engines. This single-canister filter with bypass eliminates the need for a remote bypass filter.

Mechanical overtightening of the oil and fuel filters can distort the threads or damage the filter element seal. Install the filter as specified by the filter manufacturer.

Wait until the coolant temperature is below 50°C (120°F) before removing the coolant system pressure cap. Failure to do so can cause personal injury from heated coolant spray.

Cummins B and C Series engines should have initial valve adjustments at 24,000 miles, then every 48,000 miles afterward.

Cummins recommends the cooling system be drained and flushed every two years and refilled with a 50/50 mixture of low-silicate antifreeze and water. This provides freeze protection to -34°F. Freeze protection decreases above 68% antifreeze.

Never use caustic cleaners in the cooling system. Aluminum components will be damaged.

Cummins recommends that fuel filters be changed at least every other oil change. Fuel/water separator filters should be checked daily - drain any accumulated water. Do not drain an excessive amount of fuel out or re-priming the fuel system may be required to get engine started.

It is critical to engine life to use high-quality SAE 15W-40 heavy-duty engine oil such as Premium Blue®, which meets API performance classification for CE or CF-4. Midrange engines require SG classification due to sliding cam followers.

Fill the oil filters with clean lubricating oil when changing the engine oil to ensure immediate bearing lubrication when restarting the engine. Failure to pre-lube the oil filter may cause bearing damage.

Cummins requires that a fuel-water separator be used with all '91 N14 and L10 electronic engines. Cummins recommends that a fuel-water separator be installed in the fuel supply on all other engine series. Fuel-water separators will remove water in diesel fuel, preventing damage to the fuel system.

Cummins used/dirty filter maximum restriction is 510mm H20 (20 in. H20) for naturally aspirated midrange engines (B and C Series) and 635mm H20 (25 in. H20) for all turbocharged midrange, heavy-duty and high-horsepower engines. Excessive air intake restriction can result in black smoke under load, poor fuel consumption, low power and increased soot levels.

Cummins requires that a fuel pre-filter must be installed before the lift pump on B and C Series midrange engines.