Tune-Up - Major

Complete major tune-up service for the 5.9L Cummins diesel engine, including fuel filter replacement, air filter service, crankcase breather filter replacement, belt inspection, and comprehensive fluid level checks.

Warnings

Tools required

Parts

• Fuel filter/water separator assembly × 1 — Mopar 68197867AA or equivalent
• Engine air filter × 1 — Use OEM specification
• Crankcase breather filter × 1 — Mopar 68003703AA or equivalent
• Engine oil filter × 1 — Mopar MO-090 or equivalent
• Serpentine belt × 1 — Inspect and replace if worn
• Fuel filter O-rings/seals × 1 — Usually included with filter assembly

Fluids

• 15W-40 diesel engine oil or 5W-40 synthetic — 12 qt

Preparation

1. Park vehicle on level ground and engage parking brake
2. Allow engine to cool completely if recently operated
3. Disconnect negative battery cable to prevent accidental starting
4. Gather all replacement parts and verify correct applications for 2007 5.9L Cummins
5. Place drain pan and towels in work area to catch fuel and oil spills
6. Open hood and secure in raised position

Procedure

1. 1

   Replace engine air filter
   Locate the air filter housing on the driver side of the engine bay. Release the spring clips or screws securing the air box cover. Lift the cover and remove the old air filter element. Inspect the housing for debris or damage and clean if necessary. Install the new air filter element ensuring proper seating in the housing. Secure the air box cover with all clips or screws.
2. 2

   Replace crankcase breather filter
   Locate the crankcase breather filter canister on top of the valve cover toward the front of the engine. Rotate the filter canister counterclockwise to unlock and remove it from the mounting base. Discard the old filter element. Install the new crankcase breather filter by aligning the tabs and rotating clockwise until it locks into place. Verify the filter is securely seated.
3. 3

   Drain fuel/water separator
   Locate the fuel filter/water separator assembly mounted on the driver side of the engine block. Place a drain pan beneath the unit. Open the drain valve at the bottom of the separator bowl by turning counterclockwise. Allow all fuel and water to drain completely into the pan. Close the drain valve by turning clockwise until snug. Dispose of drained fuel and water mixture properly according to local regulations.
   ⚠Diesel fuel will drain from this assembly. Ensure adequate ventilation and keep away from ignition sources.
4. 4

   Remove fuel filter assembly
   Using fuel line disconnect tools, carefully disconnect the fuel supply and return lines from the filter head. Label lines if necessary for correct reinstallation. Using a fuel filter wrench or strap wrench, turn the fuel filter/water separator assembly counterclockwise to remove it from the filter head mounting base. Be prepared for additional fuel spillage. Remove and discard the old assembly and O-ring seals.
5. 5

   Install new fuel filter assembly
   Clean the filter head mounting surface with a shop towel. Install new O-ring seals on the filter head (if not pre-installed on new filter). Fill the new fuel filter assembly approximately 3/4 full with clean diesel fuel to aid in priming. Apply a thin film of clean diesel fuel to the O-ring seal. Thread the new filter assembly onto the filter head by hand, turning clockwise. Tighten to approximately 3/4 turn after the O-ring contacts the base, or according to markings on the filter. Do not overtighten.
   ⚠Overtightening the fuel filter can damage the O-ring seal and cause fuel leaks.
6. 6

   Reconnect fuel lines and prime system
   Reconnect the fuel supply and return lines to the filter head, ensuring they click or lock into place securely. Reconnect the fuel supply and return lines to the filter head, ensuring they seat securely. This engine uses an electric in-tank/frame-mounted lift pump for priming; cycle the ignition key ON (without cranking) several times, pausing 30 seconds each cycle, to allow the lift pump to fill and purge air from the filter. If the canister housing is equipped with a manual primer plunger, actuate it until firm resistance is felt.
7. 7

   Replace engine oil and filter
   Position drain pan under the oil pan drain plug. Remove the drain plug and allow all engine oil to drain completely (approximately 15-20 minutes). Reinstall drain plug when fully drained. Move drain pan under the oil filter located on the driver side of the engine block. Use an oil filter wrench to remove the old filter by turning counterclockwise. Clean the filter mounting surface. Apply a thin film of clean engine oil to the new filter gasket. Install the new oil filter by hand, tightening 3/4 to 1 turn after gasket contact. Using a funnel, add approximately 12 quarts (11.4 L with filter) of 15W-40 diesel engine oil (or 5W-40 synthetic) through the oil fill cap, then verify level on dipstick.
   ⚠Hot engine oil can cause severe burns. Ensure engine is cool before draining.
8. 8

   Inspect serpentine belt
   Visually inspect the serpentine belt for cracks, glazing, fraying, or missing ribs. This engine uses an automatic spring-loaded belt tensioner; do not measure deflection manually. Verify the tensioner arm position is within the wear-indicator range and that the tensioner moves freely without binding. If belt shows signs of wear or damage, note the belt routing diagram on the fan shroud or engine compartment, release belt tensioner using a breaker bar, and remove the old belt. Install new belt following the routing diagram exactly. If belt is in good condition, proceed to next step.
   ⚠Keep hands and tools clear of moving pulleys and fan blades.
9. 9

   Inspect and clean battery terminals
   Inspect battery terminals and cable connections for corrosion, damage, or looseness. If corrosion is present, use a battery terminal cleaning brush and wire brush to clean both the terminals and cable clamps thoroughly. Ensure connections are tight and free of corrosion. Check battery hold-down bracket for security.
10. 10

    Check all fluid levels
    With engine cool, check and top off the following fluids as needed: coolant level in overflow reservoir (use HOAT coolant 50/50 mix only), power steering fluid reservoir (ATF+4), brake fluid reservoir (DOT 3), windshield washer fluid reservoir, transmission fluid level per dipstick (engine warm, transmission in park on level ground), and front/rear differential fill plugs if accessible. Check transfer case fluid level if accessible. Document any significant fluid consumption for future reference.
    ℹ️Transmission fluid level check requires specific procedure: engine at operating temperature, transmission in park, on level ground. Refer to owner's manual for exact procedure.
11. 11

    Inspect cooling system hoses and clamps
    Visually inspect all radiator hoses, heater hoses, and coolant connections for cracks, soft spots, bulges, or leaks. Check all hose clamps for tightness and corrosion. Squeeze accessible hoses to check for internal deterioration or collapse. Replace any suspect hoses and tighten loose clamps as needed.
12. 12

    Reconnect battery and test start
    Reconnect the negative battery cable and tighten securely. Turn the ignition key to the ON position (do not start) and wait for the 'Wait to Start' light to extinguish (approximately 10-30 seconds depending on ambient temperature). This allows the intake air heater to cycle. Start the engine and allow it to idle. Monitor for any fuel leaks around the fuel filter assembly and connections. Check for unusual noises, smoke, or warning lights. Allow engine to reach operating temperature.

Reassembly

1. Ensure all fuel connections are secure and leak-free before operating vehicle
2. Verify oil level on dipstick after engine has run and oil has settled (5 minutes after shutdown)
3. Double-check that all tools and materials have been removed from engine compartment
4. Ensure air filter housing cover is properly sealed to prevent unfiltered air intake

Verification

• Start engine and verify normal operation with no warning lights, unusual noises, or smoke
• Check for fuel leaks around filter assembly while engine is running
• Verify oil pressure gauge shows normal pressure (10+ psi at idle when warm)
• Inspect ground under vehicle after 10 minutes of running for any fluid leaks
• Test drive vehicle to confirm normal operation and performance
• Recheck engine oil level after test drive and top off if necessary
• Monitor 'Water in Fuel' indicator light (if equipped) - it should remain off during operation

More procedures for this vehicle