This procedure removes and replaces the mechanical fuel pump on a 1966 Chevrolet Corvette with 327ci V8 engine, including fuel line disconnection and proper fuel system safety protocols.

Warnings

Tools required

Parts

• Mechanical fuel pump × 1 — Use OEM specification for 1966 327 V8
• Fuel pump mounting gasket × 1 — Use OEM specification
• Fuel pump pushrod (inspect and replace if worn) × 1 — Use OEM specification

Preparation

1. Verify vehicle is equipped with carburetor and mechanical fuel pump (located on right side of engine block, driven by camshaft eccentric)
2. Park vehicle on level ground outdoors or in well-ventilated area away from ignition sources
3. Place fire extinguisher within immediate reach of work area
4. Allow engine to cool completely (minimum 2 hours after last operation)
5. Disconnect negative battery cable to eliminate ignition sources
6. Place drain pan under fuel pump area to catch fuel spillage
7. Have multiple shop rags ready to contain fuel spills immediately

Procedure

1. 1

   Relieve fuel system pressure
   This is a low-pressure mechanical fuel system. There is no significant residual pressure to relieve; simply ensure the engine is off and cool. Be aware that fuel remaining in the lines, float bowl, and pump will drain when fittings are loosened. This empties the carburetor float bowl and reduces line pressure. If engine will not start, proceed with caution as full fuel pressure remains in lines.
2. 2

   Locate and access fuel pump
   The mechanical fuel pump is mounted on the right side of the engine block, approximately halfway back, driven by an eccentric on the camshaft. On 1966 Corvettes, access is somewhat restricted by the chassis rail. Position drain pan directly beneath pump. Use flashlight to identify the inlet line (from fuel tank), outlet line (to carburetor), and two mounting bolts.
3. 3

   Disconnect fuel inlet line
   Using proper fuel line wrench (not adjustable pliers, which will round fittings), loosen the inlet line fitting at the fuel pump. The inlet line comes from the rear of the vehicle. Hold the pump inlet fitting stationary with one wrench while turning the line nut counterclockwise with the fuel line wrench. Fuel will drain from this line. Allow fuel to drain into pan, then plug line opening with clean shop rag to prevent further leakage and contamination.
4. 4

   Disconnect fuel outlet line
   Using fuel line wrench, disconnect the outlet line that runs forward to the carburetor. Hold pump outlet fitting stationary while loosening line nut. Less fuel should drain from this line. Plug this line opening with clean shop rag as well. Keep both disconnected lines elevated above pump level if possible to minimize drainage.
5. 5

   Remove fuel pump mounting bolts
   Remove the 2 fuel pump mounting bolts using a 1/2" socket or combination wrench. These bolts thread into the front of the engine block. Support the fuel pump as you remove the second bolt to prevent it from dropping. Note the orientation of the pump and any spacer or thick gasket between pump and block.
6. 6

   Remove fuel pump and pushrod
   Pull the fuel pump straight away from the engine block. The pump actuating pushrod (a steel rod approximately 4-5 inches long) may come out with the pump, fall into the engine, or remain in its bore in the timing cover. Carefully retrieve the pushrod and inspect it for wear on the eccentric contact end. If pushrod shows grooving, pitting, or wear exceeding 0.020 inch depth, replace it. If pushrod falls into engine, use magnetic pickup tool or carefully fish it out.
7. 7

   Clean mounting surface
   Using gasket scraper, remove all old gasket material from the engine block mounting surface on the timing cover. Surface must be completely clean and flat for proper seal. Use wire brush to clean bolt holes. Inspect mounting surface for damage, warping, or cracks. Wipe surface clean with shop rag dampened with carburetor cleaner or mineral spirits. Ensure no debris can fall into engine.
8. 8

   Inspect and lubricate pushrod
   If reusing original pushrod (and it shows minimal wear), wipe it clean. Apply a thin coat of engine oil to both ends of the pushrod. Insert pushrod into its bore in the engine block. The pushrod should slide in easily and the rounded end (which contacts the camshaft eccentric) should face outward. Pushrod will drop down approximately 2-3 inches and rest on the camshaft eccentric.
9. 9

   Position new fuel pump gasket
   Place new fuel pump mounting gasket over the mounting studs/holes on the timing cover. Gasket should lay flat against mounting surface. Some gaskets have adhesive backing; if not, a thin film of gasket sealer can be used, but is not required if surfaces are clean and flat. Ensure gasket holes align perfectly with mounting bolt holes.
10. 10

    Install new fuel pump
    Rotate engine crankshaft by hand (using breaker bar on crankshaft pulley bolt) until the camshaft eccentric is at its lowest point. This allows the fuel pump arm to clear the pushrod with minimal spring tension. Align fuel pump with mounting holes and pushrod bore, then push pump into position while compressing the pump arm slightly. The pump arm must engage the pushrod properly. You may feel spring resistance as pump arm contacts pushrod.
11. 11

    Install and torque mounting bolts
    Start both mounting bolts by hand to ensure proper thread engagement. Tighten bolts in alternating pattern (not one fully, then the other). Torque mounting bolts to 25 ft-lb. Do not overtighten as this can crack the fuel pump body or strip threads in the cast-iron block. Verify pump sits flush against gasket with no gaps.
12. 12

    Reconnect fuel lines
    Remove shop rags from fuel line ends. Inspect line fittings and flare seats for damage or deformation. Thread inlet line (from tank) onto pump inlet fitting by hand first, then tighten with fuel line wrench while holding pump fitting stationary. Tighten outlet line (to carburetor) in same manner. Tighten fittings snugly but do not overtighten—flare fittings seal on tapered seats, not by excessive force. Typical tightness is 12-18 ft-lb but this is done by feel with line wrenches.
13. 13

    Prime fuel pump
    Before starting engine, manually prime the fuel pump by rotating the engine crankshaft several revolutions using breaker bar on crankshaft pulley bolt. This cycles the pump arm and begins drawing fuel from tank. Continue until you feel resistance indicating fuel is moving through the system. Check all connections for leaks during this process.
14. 14

    Reconnect battery and start engine
    Reconnect negative battery cable. Have fire extinguisher ready. Start engine and immediately inspect all fuel connections for leaks. Engine may crank longer than normal on first start as fuel system reprimes. Once running, inspect fuel pump body, inlet fitting, outlet fitting, and mounting gasket area for any fuel seepage. Check for proper fuel pressure by observing steady fuel delivery (engine should run smoothly without fuel starvation).

Reassembly

1. All reassembly steps are included in the main procedure above

Verification

• Engine starts readily and runs smoothly at idle and under acceleration without fuel starvation or hesitation
• No fuel leaks visible at pump body, inlet fitting, outlet fitting, or mounting gasket area (inspect with engine running and after 5 minutes of operation)
• No fuel odor present around pump area during or after operation
• Fuel pump operates quietly without excessive mechanical noise (light ticking is normal)
• After 10-minute test drive, re-inspect all connections for seepage or leaks

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