Valve Seals

Replace valve stem seals on the 302ci V8 to stop oil consumption and smoking without removing cylinder heads, requiring intake manifold removal and valve spring compression.

Warnings

Tools required

Parts

• Valve stem seal set (16 seals) × 1 — Use OEM specification or Fel-Pro SS72101
• Intake manifold gasket set × 1 — Fel-Pro MS90032 or equivalent
• Valve cover gaskets × 2 — Use OEM specification
• Carburetor base gasket × 1 — Use OEM specification
• RTV silicone sealant (grey) × 1 — Permatex 81160 or equivalent
• Engine oil × 1 — 10W-30 or 10W-40

Fluids

• 10W-30 or 10W-40 conventional engine oil — 5 qt
• Ethylene glycol green 50/50 coolant — 2 qt

Preparation

1. Ensure engine is cold before beginning work
2. Disconnect negative battery cable
3. Remove air cleaner assembly and note all vacuum line routing
4. Label and photograph all vacuum lines, electrical connections, and linkage before disconnection
5. Drain approximately 2 quarts of coolant from radiator to prevent spillage when removing intake manifold
6. Place shop towels around intake manifold area to catch any residual coolant

Procedure

1. 1

   Remove intake manifold
   Disconnect all vacuum lines from carburetor and intake manifold. Disconnect throttle linkage, transmission kickdown linkage (if automatic), and choke cable. Remove distributor cap and mark rotor position. Disconnect coolant hoses from intake manifold (heater hose and bypass hose). Remove carburetor (4 nuts at base). Remove 12 intake manifold bolts in reverse order from center outward. Carefully lift intake manifold off engine, breaking RTV seal at front and rear. Remove and discard old gaskets.
2. 2

   Remove valve covers
   Disconnect PCV valve and breather. Remove 6 valve cover bolts from each side. Tap valve covers gently with rubber mallet to break gasket seal. Lift valve covers off and set aside. Remove and discard old gaskets. Inspect valve train for obvious damage or excessive wear.
3. 3

   Remove rocker arms for cylinder 1
   Rotate engine to bring cylinder 1 to TDC on compression stroke (both valves closed, rotor pointing to cylinder 1 on distributor). Loosen rocker arm fulcrum bolts for cylinder 1 intake and exhaust valves. Remove bolts, fulcrums, and rocker arms. Keep components organized by cylinder for reassembly. Verify both valve springs are fully extended (valves closed).
4. 4

   Remove spark plug and install air adapter
   Remove spark plug from cylinder 1 using spark plug socket. Thread compressed air adapter into spark plug hole hand-tight. Connect air hose and apply 90-100 PSI air pressure to cylinder. Listen for air escaping from carburetor (intake valve leak) or exhaust (exhaust valve leak). If significant air loss, rotate engine slightly to seat valves better or consider alternate piston stop method.
5. 5

   Compress valve springs and remove keepers for cylinder 1
   With air pressure holding valves up, position valve spring compressor tool on intake valve spring retainer. Compress spring approximately 1/4 inch until keepers are accessible. Use magnetic pickup tool or needle nose pliers to carefully remove both valve keepers from valve stem groove. Slowly release spring compressor pressure. Remove retainer and spring. Repeat process for exhaust valve. Keep intake and exhaust springs separate if they differ.
6. 6

   Remove old seals and install new seals for cylinder 1
   Using pliers or seal removal tool, carefully pull old valve stem seals off valve guides. Inspect valve stem for scoring or damage. Check valve guide for excessive wear by attempting to wiggle valve stem (minimal side-to-side movement is acceptable). Lubricate new valve stem seal with clean engine oil. Position new seal on valve guide. Using seal installation tool or appropriately sized deep socket, gently tap seal down onto guide until it seats against guide shoulder. Do not hammer directly on seal or force past seat point. Install seals on both intake and exhaust valves.
7. 7

   Reinstall springs and keepers for cylinder 1
   Place valve spring and retainer back over valve stem (ensure spring orientation matches original if springs are directional). Position valve spring compressor and compress spring. Apply small amount of grease to valve keepers to hold them in place. Carefully insert both keepers into valve stem groove using magnetic tool or needle nose pliers. Ensure keepers are fully seated in groove on both sides. Slowly release spring compressor while watching keepers to ensure they stay engaged. Tap top of valve stem gently with plastic mallet to fully seat keepers if needed. Verify keepers are locked in place before removing air pressure. Repeat for second valve.
8. 8

   Reinstall rocker arms for cylinder 1
   Remove air adapter and reinstall spark plug finger-tight. Position rocker arms, fulcrums, and bolts back on cylinder 1 valves. Tighten fulcrum bolts to the positive-stop torque specification for the 302 (approximately 18-22 ft-lbs), which sets correct lifter preload automatically. Final verification will be done after all seals are replaced. Final adjustment will be done after all seals are replaced.
9. 9

   Repeat seal replacement for remaining cylinders
   Following the same procedure (steps 3-8), replace valve seals on remaining cylinders in the most convenient firing order sequence. Recommended sequence follows the firing order 1-5-4-2-6-3-7-8 (standard for the 1972 302, non-HO), which matches engine rotation and minimizes crankshaft movement. For each cylinder: rotate engine to TDC compression stroke, remove rocker arms, remove spark plug, install air adapter, compress springs, remove keepers, replace seals, reinstall springs/keepers, reinstall rocker arms, and move to next cylinder. Maintain consistent air pressure throughout each cylinder's service.
10. 10

    Adjust valves
    With all valve seals replaced, perform final valve lash adjustment. Rotate engine to position each valve at its lowest point (opposite lobe base circle). For mechanical lifters: set lash to 0.019 inch intake and 0.019 inch exhaust using feeler gauge with engine cold. Tighten rocker arm fulcrum bolt to 17-23 ft-lbs after setting proper lash. Work through all 16 valves systematically. The 1972 302 uses hydraulic lifters from the factory; mechanical lifter adjustment does not apply. Follow the hydraulic lifter procedure above. Verified detail (The mechanical lifters are standard equipment on the 1972 302ci V8, not optional. The '(if equipped)' notation is misleading as this is the correct lifter type for this engine/year.): For mechanical lifters: set lash to 0.019 inch intake and 0.019 inch exhaust using feeler gauge with engine cold. Tighten rocker arm fulcrum bolt to 17-23 ft-lbs after setting proper lash.
11. 11

    Clean and prepare mating surfaces
    Thoroughly clean intake manifold mating surfaces on cylinder heads and block using gasket scraper. Remove all old gasket material and RTV sealant. Clean surfaces with brake cleaner or carburetor cleaner and lint-free cloth. Ensure no debris falls into engine ports or oil return holes. Inspect surfaces for warping or damage. Clean valve cover mating surfaces on cylinder heads.
12. 12

    Install valve covers
    Position new valve cover gaskets on cylinder heads. Apply small dabs of RTV at corners where gaskets meet to prevent oil seepage. Set valve covers in place and install 6 bolts per side. Tighten bolts in center-outward pattern to 3-5 ft-lbs (hand-tight plus 1/4 turn). Do not overtighten as this will distort covers and cause leaks. Reconnect PCV valve and breather.
13. 13

    Install intake manifold
    Apply thin bead of grey RTV silicant (approximately 1/8 inch) to front and rear block rails where intake manifold seals. Position new intake manifold gaskets on cylinder heads, ensuring all port openings align. Carefully lower intake manifold onto engine, seating it evenly on gaskets. Install 12 intake manifold bolts finger-tight. 18.0 lb-ft (25.0 Nm) Allow RTV to cure 15-20 minutes before adding coolant. Verified detail (Precise torque specification for 1972 Ford 302ci V8 intake manifold bolts): 18.0 lb-ft (25.0 Nm)
14. 14

    Reinstall carburetor and accessories
    Install new carburetor base gasket. Mount carburetor and tighten 4 base nuts to 12-15 ft-lbs in cross pattern. Reconnect throttle linkage, transmission kickdown linkage, and choke cable. Reconnect all vacuum lines per labels or photos taken during disassembly. Verify distributor rotor is at marked position and install distributor cap. Reconnect coolant hoses to intake manifold. Reconnect all electrical connections.
15. 15

    Refill fluids and check for leaks
    Refill cooling system with approximately 2 quarts of 50/50 ethylene glycol coolant (or amount drained). Check engine oil level and top off as needed with 10W-30 or 10W-40 conventional oil. Reconnect negative battery cable. Start engine and immediately check for oil leaks at valve covers and coolant leaks at intake manifold. Allow engine to warm to operating temperature while monitoring for leaks. Check for proper oil pressure and listen for valve train noise indicating improper adjustment or low oil pressure.

Reassembly

1. Torque all fasteners to proper specifications in correct sequence
2. Double-check all vacuum lines are connected per original routing
3. Verify throttle linkage operates smoothly through full range
4. Ensure no tools or parts are left in engine valley or on top of engine

Verification

• Start engine and listen for abnormal valve train noise indicating dropped valve keepers or improper adjustment
• Monitor oil pressure gauge for proper pressure (40-60 PSI at operating temperature)
• Allow engine to reach full operating temperature and check for oil leaks at valve covers
• Check for coolant leaks at intake manifold gaskets and hose connections
• Test drive vehicle and monitor for white/blue smoke from exhaust (should be significantly reduced or eliminated after 20-30 miles of break-in)
• Recheck valve cover bolts after first 50 miles as gaskets may settle

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