This procedure removes and replaces the high pressure fuel pump on the 6.7L Cummins diesel engine, including fuel system depressurization, pump removal, and proper reinstallation with new seals.

Warnings

Tools required

Parts

• High pressure fuel pump × 1 — Use OEM Bosch CP3 pump or Mopar 68193383AB
• High pressure fuel pump O-ring kit × 1 — Use OEM specification
• Fuel line O-rings × 4 — Use OEM specification
• Fuel filter × 1 — Mopar 68197867AA recommended during service
• Shop towels × 1 — Generic

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect both battery negative terminals and wait 5 minutes for system capacitors to discharge
3. Remove engine cover by lifting upward on perimeter clips
4. Allow engine to cool completely if recently operated (minimum 2 hours)
5. Place absorbent pads under fuel filter housing and pump area
6. Relieve fuel system pressure: Disconnect fuel pump relay (relay R13 in PDC) and crank engine for 15 seconds. Do not start engine
7. Ensure work area is clean and free of debris to prevent fuel system contamination

Procedure

1. 1

   Disconnect fuel supply and return lines
   Locate the fuel supply line from the filter housing to the high pressure pump inlet and the fuel return line. Use flare nut wrenches to loosen the fuel line fittings at the pump. Have catch container ready as residual fuel will drain. Once fittings are loose, carefully remove lines and cap all openings immediately with clean plugs to prevent contamination. Remove and discard all O-rings from the fittings.
   ⚠Expect significant fuel spillage. Capture all fuel in approved container for proper disposal.
2. 2

   Disconnect high pressure fuel rail line
   Locate the high pressure line running from the pump outlet to the fuel rail. This line operates at extreme pressure and requires careful handling. Use proper flare nut wrench on the pump outlet fitting and loosen carefully. Support the fuel line to prevent bending. Once disconnected, cap the pump outlet and line end immediately. Inspect the connection points for any damage or scoring that would indicate contamination.
   ⚠️High pressure line fittings are precision machined. Any damage will cause leaks at dangerous pressures. Inspect carefully and replace if any damage is observed.
3. 3

   Disconnect electrical connectors
   Locate the fuel control actuator (FCA) electrical connector on the rear of the high pressure pump. Press the red release tab and disconnect the connector. Move the wiring harness out of the work area to prevent damage. If connector is corroded or difficult to remove, use electrical contact cleaner and allow to dry before disconnecting.
4. 4

   Remove pump mounting bracket
   The high pressure pump is secured to the engine with a mounting bracket. Remove the bracket bolts using appropriate socket. There are typically three bolts securing the bracket. Support the pump with one hand while removing the final bolt as the pump assembly is heavy. Remove the bracket and set aside.
   Torque spec

   Bracket Bolts27 Nm (20 lb-ft)
5. 5

   Remove high pressure pump mounting bolts
   Locate the two mounting bolts that secure the pump directly to the gear housing on the driver side of the engine block. These bolts pass through the pump mounting flange. Remove both mounting bolts completely. Keep these bolts clean as they will be reused.
   ⚠Pump is heavy and may be seized to mounting surface. Be prepared to support weight and work pump free carefully.
   Torque spec

   Mounting Bolts37 Nm (27 lb-ft)
6. 6

   Remove pump from engine
   With mounting bolts removed, carefully work the pump away from the gear housing. The pump drive gear is engaged with the engine timing gears, so gentle rocking motion may be needed. Pull pump straight out to disengage the drive coupling. Once free, remove pump from engine bay. Cover the gear housing opening immediately with clean shop towel to prevent debris entry.
   ⚠️The gear housing opening exposes critical engine timing components. Any debris or contamination entering this area will cause catastrophic engine damage. Keep opening covered at all times.
7. 7

   Inspect and clean mounting surfaces
   Remove the shop towel temporarily and inspect the gear housing opening and drive gear. Look for any metal shavings, scoring, or damage that would indicate pump or gear failure. Clean the pump mounting flange surface on the gear housing using brass brush and clean solvent. Wipe completely dry with lint-free cloth. Inspect the pump mounting bolt holes and threads for damage. Replace the cover towel when cleaning is complete.
8. 8

   Prepare new pump for installation
   Remove new high pressure pump from packaging in clean area. Verify the pump drive gear rotates smoothly by hand. Install new O-rings from the O-ring kit onto the pump inlet and outlet ports, lubricating with small amount of clean diesel fuel. Do not use petroleum jelly or other lubricants. Install the large mounting flange O-ring into the groove on the pump mounting face. Verify all O-rings are seated properly without twisting.
   ⚠Damaged or improperly seated O-rings will cause fuel leaks at high pressure. Inspect carefully before installation.
9. 9

   Set pump timing
   This is the most critical step. Remove cover from gear housing. Rotate engine by hand using 15/16 inch socket on crankshaft bolt until timing marks on gear housing align (engine at TDC cylinder 1). Install the timing gauge tool into the pump mounting holes on the gear housing per tool instructions. The dial indicator should show the specified timing measurement per service manual (typically 0.126-0.134 inches pump gear engagement). Install new pump onto the gear housing, carefully aligning the drive coupling with the engine gear. Verify timing measurement remains within specification as pump is seated. If timing is incorrect, pump must be removed and drive gear repositioned.
   ⚠️Incorrect pump timing will cause engine damage and pump failure. Do not proceed unless timing measurement is within specification. This requires special tooling and experience.
10. 10

    Install pump mounting bolts
    With pump properly seated and timing verified, install the two mounting bolts through the pump flange into the gear housing. Start both bolts by hand to ensure proper thread engagement. Tighten bolts in alternating pattern to specified torque. After torquing, verify timing measurement has not changed. Remove timing gauge tool.
    Torque spec

    Mounting Bolts37 Nm (27 lb-ft)
11. 11

    Reinstall mounting bracket
    Position the pump mounting bracket over the pump body and align with bolt holes. Install all bracket bolts and tighten to specified torque in star pattern to ensure even clamping force.
    Torque spec

    Bracket Bolts27 Nm (20 lb-ft)
12. 12

    Reconnect high pressure fuel rail line
    Remove protective caps from pump outlet and high pressure line. Inspect fitting threads and sealing surfaces for any damage. Install new O-ring onto the line fitting, lubricating with clean diesel fuel. Carefully thread the high pressure line fitting onto the pump outlet by hand to ensure proper thread engagement. Use flare nut wrench and torque to specification. Support the fuel line during tightening to prevent stress on the fitting.
    ⚠️High pressure line connection must be torqued precisely. Under-torque will cause high pressure fuel leak. Over-torque will damage precision threads.
    Torque spec

    Fuel Line Fittings25 Nm (18 lb-ft)
13. 13

    Reconnect supply and return lines
    Install new O-rings onto the fuel supply and return line fittings, lubricating with clean diesel fuel. Connect supply line from filter housing to pump inlet and return line to pump return port. Thread fittings by hand first to verify proper engagement. Tighten fuel line fittings to specified torque using flare nut wrenches.
    ⚠Ensure new O-rings are installed on all fuel fittings. Reusing old O-rings will cause fuel leaks.
    Torque spec

    Fuel Line Fittings25 Nm (18 lb-ft)
14. 14

    Reconnect electrical connector
    Reconnect the fuel control actuator (FCA) electrical connector to the pump. Ensure connector locks with audible click. Gently tug on connector to verify it is fully seated and locked.
15. 15

    Prime fuel system and check for leaks
    Reinstall fuel pump relay (R13) in PDC. Reconnect both battery negative terminals. Turn ignition key to ON position (do not start) and allow fuel system to prime for 30 seconds. Turn key OFF and wait 10 seconds. Repeat this cycle 4 times to fully prime the system. Carefully inspect all fuel connections at the pump for any signs of fuel seepage. Check high pressure line connection especially carefully. After confirming no leaks during priming, start the engine and allow to idle. Monitor all connections for leaks. Engine may run rough for 30-60 seconds while air purges from high pressure system.
    ⚠️Any fuel leak at high pressure line connection is extremely dangerous. If leak is observed, shut down immediately and correct the issue before proceeding.

Reassembly

1. Reinstall engine cover by pressing down on perimeter clips until they engage
2. Clean any spilled fuel from engine bay and surrounding areas with appropriate cleaner
3. Dispose of old fuel, O-rings, and contaminated materials per local regulations
4. Reset any diagnostic trouble codes using appropriate scan tool if check engine light is illuminated

Verification

• Start engine and verify smooth idle with no excessive noise from fuel pump area
• Check all fuel connections for leaks with engine running at idle and at 1500 RPM
• Verify no fuel odor in engine compartment
• Test drive vehicle and verify normal power delivery and acceleration
• Monitor for any fuel-related diagnostic trouble codes over next 50 miles of operation
• Recheck all fuel connections for seepage after first drive cycle
• Verify fuel rail pressure is within specification using scan tool (approximately 23,000-26,000 PSI at idle)

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