Intake Manifold Gasket

Replace the intake manifold gasket on a 1972 Ford F-100 with 302ci V8 engine to resolve vacuum leaks, coolant leaks, or oil seepage at the manifold mating surface.

Warnings

Tools required

Parts

• Intake manifold gasket set × 1 — Fel-Pro MS90114 or equivalent
• Intake manifold end seals (front and rear) × 1 — Included in gasket set or separate
• RTV silicone sealant (high-temp) × 1 — Use OEM specification
• Carburetor base gasket × 1 — Use OEM specification
• Thermostat housing gasket (if disturbed) × 1 — Use OEM specification

Fluids

• Ethylene glycol green 50/50 coolant — 15 qt

Preparation

1. Park vehicle on level surface and allow engine to cool completely (minimum 2 hours after last operation).
2. Disconnect negative battery cable to prevent electrical shorts.
3. Place drain pan under radiator and drain coolant by opening petcock at bottom of radiator.
4. Photograph or label all vacuum hoses, ignition wires, and electrical connections for reference during reassembly.
5. Remove air cleaner assembly and set aside.

Procedure

1. 1

   Drain cooling system and disconnect upper radiator hose
   With coolant already draining from preparation, disconnect the upper radiator hose from the thermostat housing at the front of the intake manifold. Use pliers to squeeze and slide the hose clamp back, then twist and pull the hose free. Allow remaining coolant to drain into pan.
2. 2

   Remove carburetor and throttle linkage
   Disconnect fuel line at carburetor inlet using a flare nut wrench. Plug the fuel line to prevent spillage. Disconnect throttle linkage, kickdown linkage (if automatic transmission), and choke cable. Label and disconnect all vacuum lines from carburetor ports. Remove the 4 carburetor mounting nuts and lift carburetor straight up off the manifold studs. Cap or plug the intake manifold opening to prevent debris entry.
3. 3

   Disconnect distributor and ignition components
   Mark the position of the distributor rotor relative to the distributor body and the body relative to the intake manifold with paint or scribe marks. Remove the distributor hold-down bolt and clamp, then carefully lift the distributor straight out. Note the position of the vacuum advance canister. Disconnect ignition coil wire and any other ignition wiring attached to the manifold or near the work area.
4. 4

   Remove accessory components and brackets
   Remove the thermostat housing (2 bolts) at the front of the intake manifold if it interferes with manifold removal. Disconnect heater hoses from the rear of the manifold. Remove any brackets, ground straps, or temperature sender wires attached to the intake manifold. On models with emission controls, disconnect EGR valve and associated vacuum lines.
5. 5

   Disconnect remaining vacuum lines and PCV system
   Disconnect the PCV valve from the valve cover and any hose routing through the carburetor base. Remove all remaining vacuum lines from manifold ports, including brake booster line if present. Label each connection for reassembly. Remove any vacuum tree or distribution block mounted to the manifold.
6. 6

   Remove intake manifold bolts
   The Ford 302 intake manifold uses 12 bolts securing it to the cylinder heads. Working from the ends toward the center, loosen each bolt 1-2 turns in sequence. Once all bolts are loosened, remove them completely and keep them organized. Note that the front and rear center bolts are often longer than the outer bolts.
7. 7

   Remove intake manifold
   Carefully lift the intake manifold straight up off the engine. The manifold may be stuck due to old gasket material or sealant. If stuck, gently pry at a reinforced boss (not the sealing surface) using a pry bar wrapped in a rag. Once free, lift the manifold away and set it on a clean workbench with the sealing surface facing up to prevent damage.
8. 8

   Remove old gaskets and clean all surfaces
   Remove all old gasket material from the intake manifold mating surface and cylinder head surfaces using a gasket scraper. Be extremely careful not to gouge the cast iron cylinder heads or the intake manifold sealing surface. Remove the old front and rear intake manifold end seals. Clean all surfaces thoroughly with brake cleaner and shop rags. Use a shop vacuum to remove all debris from the lifter valley to prevent contamination of the oil system. Inspect surfaces for damage, warpage, or cracks.
9. 9

   Install new end seals and apply RTV
   Install the new front and rear intake manifold end seals, positioning them in the block rail grooves at the front and rear of the engine. Apply a thin bead (approximately 1/8 inch) of high-temp RTV silicone at the four corners where the end seals meet the cylinder head gaskets. This prevents coolant and oil leaks at these critical junctions. Allow RTV to tack up for 5 minutes before proceeding.
10. 10

    Install intake manifold gaskets
    Position the new intake manifold gaskets on each cylinder head, aligning the port openings and bolt holes. The gaskets are side-specific (left and right). Some gaskets have alignment tabs that lock into the head; ensure these are properly seated. Do not apply additional RTV or sealer to the gasket faces unless specified by the gasket manufacturer.
11. 11

    Install intake manifold
    Carefully lower the intake manifold onto the engine, aligning it with the gaskets and end seals. Ensure all port openings align correctly and no gaskets have shifted. Insert all 12 intake manifold bolts finger-tight, starting with the center bolts and working outward. Verify that the manifold sits flush against the heads before proceeding to torque.
12. 12

    Torque intake manifold bolts
    Using a torque wrench, tighten the intake manifold bolts to 23-25 lb-ft in the proper sequence: start at the center bolts and work outward in a crossing pattern, alternating side to side. Make two complete passes: first to 12 lb-ft, then final torque to 23-25 lb-ft. This ensures even clamping force and prevents gasket distortion or leaks. Verified detail (Ford 289/302 Windsor intake manifold bolts are typically torqued to approximately 23-25 lb-ft (some specs call for progressive stages up to 23 lb-ft), not 18 lb-ft. Verify against Ford shop manual spec for the 302.): Using a torque wrench, tighten the intake manifold bolts to 23 lb-ft (31 Nm) in the proper sequence: start at the center bolts and work outward in a crossing pattern, alternating side to side. Make progressive passes: first to 12 lb-ft, then to 18 lb-ft, then final torque to 23 lb-ft.
    Torque spec

    Intake Manifold Bolts25 Nm (18 lb-ft)
13. 13

    Reinstall distributor
    With the engine in the same position as when the distributor was removed, install the distributor by aligning the rotor with the mark made during disassembly. The distributor shaft gear is helical, so the rotor will rotate slightly as the gear engages. Align the distributor body with its original position mark, then install the hold-down clamp and bolt. Snug the bolt but leave it loose enough to allow timing adjustment later.
14. 14

    Reinstall carburetor and accessories
    Install a new carburetor base gasket on the manifold studs. Lower the carburetor onto the studs and install the 4 mounting nuts. Tighten evenly in a crossing pattern to prevent base warpage. Reconnect throttle linkage, kickdown linkage, and choke cable. Reconnect all vacuum lines according to your labels or photos. Reconnect fuel line using new gaskets if the fitting is reusable.
15. 15

    Reconnect cooling system and accessories
    Reinstall thermostat housing with new gasket if it was removed. Reconnect upper radiator hose and heater hoses, securing with hose clamps. Reinstall any brackets, ground straps, temperature senders, and emission control components. Reconnect ignition coil wire and PCV valve. Reinstall air cleaner assembly.
16. 16

    Refill cooling system
    Close radiator petcock. Refill cooling system with fresh 50/50 ethylene glycol coolant mixture. Fill radiator to the top and add coolant to overflow reservoir to the FULL mark. Leave radiator cap off for initial startup to allow air to escape.

Reassembly

1. Reconnect negative battery cable.
2. Double-check that all vacuum lines, electrical connections, and hoses are properly connected.
3. Verify that no tools or rags have been left in the engine compartment.

Verification

• Start engine and allow it to reach operating temperature while monitoring for leaks around the intake manifold perimeter.
• Check for coolant leaks at the front and rear end seals and at the thermostat housing.
• Check for oil leaks along the lower intake manifold gasket area.
• Listen for vacuum leaks (hissing sound) at idle; engine should idle smoothly without rough running.
• Verify that coolant level is stable and no air pockets remain in the system (squeeze upper radiator hose to burp air).
• Check ignition timing with timing light and adjust distributor if necessary to factory specification (typically 6-8 degrees BTDC at idle for 1972 302).
• Road test vehicle to verify proper engine performance, smooth acceleration, and no overheating.

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