Exhaust Manifold Gasket

Replace exhaust manifold gaskets on both banks of the 302ci V8, including removal of manifolds, cleaning mating surfaces, and reinstallation with proper torque sequence.

Warnings

Tools required

Parts

• Exhaust manifold gasket set (left and right) × 1 — Use OEM specification or Fel-Pro MS 90024
• Exhaust manifold studs (if damaged) × 8 — Ford 3/8"-16 x 2" exhaust studs
• Exhaust manifold nuts × 16 — 3/8"-16 self-locking nuts
• Exhaust pipe flange gaskets × 2 — 2.5" donut gaskets

Preparation

1. Park vehicle on level ground and allow engine to cool completely (minimum 4 hours)
2. Disconnect negative battery cable
3. Apply penetrating oil to all visible exhaust manifold nuts and exhaust pipe flange nuts
4. Raise vehicle and support securely on jack stands if improved access is needed for exhaust pipe disconnection
5. Remove air cleaner assembly for improved access to driver side manifold

Procedure

1. 1

   Disconnect exhaust pipes from manifolds
   Working from underneath the vehicle, remove the 2 nuts securing each exhaust pipe to the manifold flange. Remove and discard the donut gaskets. Support exhaust pipes with wire or jack stand to prevent strain on hangers.
2. 2

   Remove heat shields (if equipped)
   Some F-100 models have heat shields attached to exhaust manifolds. Remove the bolts securing any heat shields present and set shields aside for reinstallation.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
3. 3

   Remove spark plug wire brackets
   The driver side manifold typically has 1-2 spark plug wire brackets attached to manifold studs. Remove these brackets and route spark plug wires clear of work area.
4. 4

   Remove driver side exhaust manifold
   Remove all 8 nuts securing the driver side manifold to the cylinder head. Work from center outward to prevent warping. The center rear nut requires a long extension with universal joint. Once all nuts are removed, lift manifold away from head. If studs come out with nuts, this is acceptable and studs will be reinstalled later.
   Torque spec

   Exhaust Manifold Nuts30 Nm (22 lb-ft)
5. 5

   Remove passenger side exhaust manifold
   Remove all 8 nuts securing the passenger side manifold to the cylinder head. The rear-most nuts are extremely difficult to access and require wobble extensions or universal joints. Work from center outward. Once all nuts are removed, lift manifold away from head, rotating as necessary to clear spark plugs and steering linkage.
   Torque spec

   Exhaust Manifold Nuts30 Nm (22 lb-ft)
6. 6

   Inspect and replace studs if necessary
   Inspect all exhaust manifold studs in cylinder heads. Replace any studs that are damaged, stripped, or pulled out during removal. Clean stud holes in cylinder head with thread chaser or tap. Install new studs using the double-nut method and seat them snugly per the manufacturer's specified stud installation torque. Do not overtighten studs. Studs thread into cast iron cylinder heads on the 302ci, but excessive torque can still damage threads.
   ⚠Do not overtighten studs into aluminum heads. Studs thread into cast iron on 302ci, but excessive torque can still damage threads.
   Torque spec

   Exhaust Manifold Studs15 Nm (11 lb-ft)
7. 7

   Remove old gasket material
   Using a flat scraper and wire brush, carefully remove all old gasket material from cylinder head mating surfaces and exhaust manifold mating surfaces. Do not gouge or scratch the sealing surfaces. Use shop vacuum to remove debris from cylinder head surface and prevent material from entering exhaust ports.
8. 8

   Inspect exhaust manifolds
   Inspect both manifolds for cracks, especially around the center ports and bolt flanges. Check mating surfaces for warping using a straightedge. Manifolds warped more than 0.010" should be resurfaced or replaced. Clean carbon buildup from manifold interiors and flanges with wire brush.
9. 9

   Install new gaskets and position driver side manifold
   Place new exhaust manifold gasket on driver side cylinder head, aligning all port openings and stud holes. Position driver side manifold onto studs, ensuring gasket remains properly aligned. Start all 8 nuts by hand to ensure proper threading.
10. 10

    Torque driver side manifold nuts
    Apply anti-seize compound to threads of all exhaust manifold nuts. Using a torque wrench, tighten the driver side manifold nuts in three stages following a center-to-ends pattern: first to 10 lb-ft, then to 15 lb-ft, then to the final torque specified in the factory shop manual (typically approx. 18-24 lb-ft for the 302). Work from the center ports outward to the end ports on each pass.
    Torque spec

    Exhaust Manifold Nuts30 Nm (22 lb-ft)
11. 11

    Install new gaskets and position passenger side manifold
    Place new exhaust manifold gasket on passenger side cylinder head, aligning all port openings and stud holes. Position passenger side manifold onto studs, rotating as necessary to clear spark plugs and steering components. Ensure gasket remains properly aligned. Start all 8 nuts by hand.
12. 12

    Torque passenger side manifold nuts
    Apply anti-seize compound to threads of all exhaust manifold nuts. Using a torque wrench, tighten the passenger side manifold nuts in three stages following a center-to-ends pattern: first to 10 lb-ft, then to 18 lb-ft, then to final torque of 28 lb-ft. Work from the center ports outward to the end ports on each pass. The rear nuts require careful attention due to limited access.
    Torque spec

    Exhaust Manifold Nuts30 Nm (22 lb-ft)
13. 13

    Reinstall heat shields and brackets
    Reinstall any heat shields removed in step 2, torquing bolts to specification. Reinstall spark plug wire brackets on driver side manifold studs.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)
14. 14

    Reconnect exhaust pipes
    Install new donut gaskets at exhaust manifold flanges. Align exhaust pipes to manifold flanges and install new nuts. Tighten exhaust pipe flange nuts evenly, alternating between the two nuts on each side to draw pipes up evenly. Final tightness should be snug but not overtorqued to prevent gasket crushing.
15. 15

    Reinstall air cleaner and reconnect battery
    Reinstall air cleaner assembly. Reconnect negative battery cable. If vehicle was raised, lower from jack stands.

Reassembly

1. Torque specifications must be followed precisely using a calibrated torque wrench
2. Anti-seize compound is required on all manifold nuts to prevent future seizure
3. Three-stage torque sequence (center-to-ends) prevents manifold warping and ensures even gasket compression

Verification

• Start engine and allow to idle. Listen for exhaust leaks at manifold-to-head interface and exhaust pipe connections
• With engine at idle, carefully feel around manifold perimeter for exhaust gas escaping (do not touch hot surfaces)
• After engine reaches operating temperature, shut off and allow to cool for 30 minutes. Re-torque all manifold nuts to 22 lb-ft while engine is warm but touchable
• Take vehicle for short test drive and re-inspect all connections for leaks
• After 50-100 miles of operation, perform final re-torque of all manifold nuts to specification

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