Complete removal and reinstallation of the cylinder head on the 6.7L Cummins diesel engine, including timing system removal, valve train disassembly, and proper head bolt torque sequence.

Warnings

Tools required

Parts

• Cylinder head gasket × 1 — Use OEM Cummins specification
• Cylinder head bolts (complete set) × 1 — Use OEM Cummins - TTY bolts, not reusable
• Valve cover gasket × 1 — Use OEM specification
• Exhaust manifold gasket × 1 — Use OEM specification
• Intake manifold gasket set × 1 — Use OEM specification
• Rocker lever pivot bolts (if reuse not allowed) × 12 — Check service manual for reusability
• Thermostat housing gasket × 1 — Use OEM specification
• Fuel injector seals and O-rings × 6 — Use OEM Cummins specification
• Engine oil × 1 — Mopar 5W-20 Synthetic Blend
• Engine coolant × 1 — Mopar OAT Purple Coolant

Fluids

• Mopar 5W-20 Synthetic Blend — 13 qt
• Mopar OAT Coolant (Purple) — 18 qt

Preparation

1. Disconnect both battery negative terminals and wait 5 minutes for system capacitors to discharge
2. Drain engine coolant completely into appropriate container
3. Drain engine oil and remove oil filter
4. Remove engine cover and upper radiator hose
5. Relieve fuel system pressure using diagnostic tool or fuel pressure relief valve
6. Remove air intake system from turbocharger to air filter housing
7. Label and photograph all electrical connectors, vacuum lines, and fuel lines before disconnection
8. Support engine with overhead hoist or engine support fixture
9. Ensure workspace is clean and organized with adequate lighting

Procedure

1. 1

   Remove Valve Cover and Accessories
   Disconnect all electrical connectors on valve cover including injector harness. Remove charge air cooler outlet tube. Unbolt and remove valve cover carefully to avoid damaging gasket mating surfaces. Remove any brackets or components attached to valve cover.
   Torque spec

   Cover Bolts22 Nm (16 lb-ft)
2. 2

   Disconnect Fuel System Components
   Disconnect high-pressure fuel lines from each injector using proper flare nut wrenches. Cap all fuel line openings immediately to prevent contamination. Remove fuel rail mounting bolts and carefully set fuel rail assembly aside. Keep fuel injectors installed in rail unless replacement is needed.
   ⚠️Even with pressure relieved, residual fuel under pressure may spray out. Wear safety glasses and have rags ready.
   Torque spec

   Mounting Bolts37 Nm (27 lb-ft)
3. 3

   Remove Intake and Exhaust Manifolds
   Disconnect EGR valve and cooler connections. Remove intake manifold mounting bolts in reverse of tightening sequence and lift manifold away. Disconnect exhaust manifold from turbocharger. Remove exhaust manifold mounting bolts and remove manifold. Inspect manifold studs for damage.
   Torque spec

   Mounting Bolts37 Nm (27 lb-ft)

   Gasket Bolts27 Nm (20 lb-ft)
4. 4

   Remove Rocker Lever Assembly
   Working from the outside bolts toward the center, loosen rocker lever pivot bolts in multiple passes to prevent bending the shaft. Once loose, remove all rocker lever assemblies as a unit. Keep pushrods in order - label or use a numbered holder. Measure pushrod length and inspect for wear or bending.
   Torque spec

   Mounting Bolts37 Nm (27 lb-ft)
5. 5

   Disconnect Coolant and Sensor Connections
   Remove thermostat housing and disconnect all coolant hoses from cylinder head. Disconnect coolant temperature sensor, camshaft position sensor, and any other sensors mounted to the head. Remove sensor mounting bolts carefully to avoid thread damage.
   Torque spec

   Sensor Bolts15 Nm (11 lb-ft)
6. 6

   Remove Cylinder Head Bolts
   Using the correct cylinder head bolt sequence diagram (reverse of installation sequence), loosen head bolts in multiple passes, approximately 1/4 turn per pass. Once all bolts are loose, remove them completely and store in order. Inspect bolts for necking or damage - all must be replaced as they are TTY type.
   ⚠Head bolts must be loosened gradually in proper sequence to prevent head warping.
   Torque spec

   Cylinder Head Bolts80 Nm (59 lb-ft) + 90°
7. 7

   Remove Cylinder Head
   Using proper lifting equipment attached to cylinder head lifting brackets, carefully break head loose from block using plastic pry points (never pry on gasket surfaces). Lift head straight up avoiding any tilting. Place head on padded wooden blocks with combustion chambers facing up. Cover block deck surface immediately with clean shop towels.
8. 8

   Clean and Inspect Mating Surfaces
   Using plastic razor blades and approved gasket remover, thoroughly clean all gasket material from block deck and cylinder head mating surfaces. Do not use metal scrapers that could gouge surfaces. Inspect block deck for flatness and cleanliness. Check for cracks around valve seats and combustion chambers. Verify cylinder head flatness is within 0.002 inch specification.
9. 9

   Prepare for Head Installation
   Inspect cylinder bores for damage or excessive wear. Ensure all dowel pins are in place on block. Clean cylinder head bolt holes in block using compressed air and ensure they are dry and free of oil or coolant (oil in bolt holes can cause false torque readings). Install new cylinder head gasket on block - do not use any sealant unless specified by manufacturer. Verify gasket orientation matches alignment dowels.
   ⚠Oil or coolant in head bolt holes will cause hydraulic lock and incorrect torque readings, potentially cracking the block.
10. 10

    Install Cylinder Head
    Using lifting equipment, carefully lower cylinder head onto block, aligning with dowel pins. Lower straight down without sliding to avoid damaging gasket. Ensure head is fully seated on all dowel pins before proceeding.
11. 11

    Install and Torque Cylinder Head Bolts
    Install NEW cylinder head bolts finger tight in their proper locations. Following the factory torque sequence diagram exactly: Step 1 - Torque all bolts to 59 lb-ft. Step 2 - Loosen all bolts completely (back off one full turn). Step 3 - Torque all bolts to 77 lb-ft. Step 4 - Using torque angle gauge, rotate each bolt an additional 90 degrees in sequence. Verify each bolt has been angle-torqued by marking bolt heads with paint pen before rotation.
    ⚠️Head bolt torque sequence is CRITICAL. Improper torque or sequence will result in head gasket failure, coolant leaks, or head warping.
    Torque spec

    Cylinder Head Bolts80 Nm (59 lb-ft) + 90°
12. 12

    Install Rocker Lever Assembly and Set Valve Lash
    Install pushrods in their original locations, ensuring they are properly seated in lifters. Install rocker lever assembly and torque pivot bolts in sequence from center outward in multiple passes. If required, adjust valve lash according to factory specifications using proper procedure (typically done with engine at specific piston positions).
    Torque spec

    Mounting Bolts37 Nm (27 lb-ft)
13. 13

    Install Manifolds and Fuel System
    Install new exhaust manifold gasket and torque manifold bolts to specification. Install new intake manifold gasket and torque intake bolts in proper sequence. Reconnect EGR components. Install fuel rail with new injector seals and O-rings, torque fuel rail mounting bolts. Reconnect high-pressure fuel lines to injectors using proper torque on flare fittings.
    Torque spec

    Mounting Bolts37 Nm (27 lb-ft)

    Gasket Bolts27 Nm (20 lb-ft)
14. 14

    Install Valve Cover and Accessories
    Install new valve cover gasket (do not over-tighten as this can distort cover and cause leaks). Install valve cover and torque bolts in criss-cross pattern to specification. Reconnect all electrical connectors to injectors and sensors. Install charge air cooler tube and all remaining brackets.
    Torque spec

    Cover Bolts22 Nm (16 lb-ft)
15. 15

    Reconnect Coolant System and Fill Fluids
    Install thermostat housing with new gasket and reconnect all coolant hoses. Fill cooling system with proper Mopar OAT purple coolant, burping system to remove air pockets. Install new oil filter and fill engine with 13 quarts of Mopar 5W-20 synthetic blend oil. Reconnect air intake system to turbocharger.
    Torque spec

    Gasket Bolts27 Nm (20 lb-ft)

Reassembly

1. Reconnect both battery negative terminals
2. Prime fuel system using diagnostic tool or by cranking engine without starting until fuel pressure builds
3. Double-check all electrical connectors, hoses, and fasteners are properly connected
4. Verify no tools or parts have been left in engine compartment

Verification

• Start engine and allow to idle, monitoring for unusual noises or vibrations
• Check for fuel leaks at all injector connections and fuel rail
• Check for coolant leaks at head gasket, thermostat housing, and all hose connections
• Check for oil leaks at valve cover gasket
• Verify engine reaches normal operating temperature and thermostat opens properly
• Check for exhaust leaks at manifold gasket
• Perform a test drive under varying loads to verify proper engine performance
• Re-check coolant level after engine cools and top off if necessary
• Monitor engine for 100 miles and re-inspect for any leaks or issues
• If available, perform cylinder leak-down test to verify head gasket seal integrity

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