EGR Tube

This procedure covers the removal and replacement of the EGR tube on a 1972 Ford F-100 with 302ci V8 engine, including disconnection from the exhaust manifold and carburetor spacer.

Warnings

Tools required

Parts

• EGR tube assembly × 1 — Use OEM specification
• EGR tube flange gasket (exhaust manifold side) × 1 — Use OEM specification
• EGR valve gasket × 1 — Use OEM specification

Preparation

1. Ensure engine has been off for at least 45 minutes to allow exhaust components to cool
2. Park vehicle on level surface and engage parking brake
3. Open hood and secure with prop rod
4. Disconnect negative battery cable to prevent electrical issues during work
5. Apply penetrating oil to all EGR tube fasteners and fittings, allow 15-20 minutes soak time

Procedure

1. 1

   Access and inspect EGR tube routing
   Locate the EGR tube running from the right-side exhaust manifold (passenger side) up to the carburetor spacer plate. Inspect the tube for cracks, excessive rust perforation, or damage. The tube has a flange connection at the exhaust manifold and a compression fitting at the carburetor spacer. Note the routing path and any brackets or clips securing the tube.
2. 2

   Disconnect EGR tube from carburetor spacer
   Using a 5/8" wrench on the compression fitting nut at the carburetor spacer, carefully loosen the nut while holding the tube steady to prevent twisting. If the fitting is seized, apply additional penetrating oil and allow soak time. Once loose, unthread the nut completely and carefully pull the tube straight down and away from the carburetor spacer fitting. Inspect the spacer fitting for damage or stripped threads.
3. 3

   Remove EGR tube support bracket
   Locate the metal support bracket that secures the EGR tube to the engine block or cylinder head. Remove the single mounting bolt using a 9/16" socket. Keep the bracket and bolt for reinstallation with the new tube.
4. 4

   Disconnect EGR tube from exhaust manifold
   At the exhaust manifold flange connection, remove the 2 nuts securing the EGR tube flange to the manifold using a 9/16" wrench or socket. Work carefully as these fasteners are often corroded. If a stud breaks off, it will need to be extracted from the manifold. Once both nuts are removed, carefully work the tube flange free from the manifold studs.
5. 5

   Remove old EGR tube
   Carefully maneuver the EGR tube out of the engine compartment. The tube will need to be angled and rotated to clear the distributor, valve cover, and other components. Take note of the routing path for installation of the new tube.
6. 6

   Clean mounting surfaces
   Using a wire brush, thoroughly clean the exhaust manifold EGR port surface where the flange gasket seats. Remove all carbon deposits and old gasket material. Clean the threads on the exhaust manifold studs. Inspect the carburetor spacer EGR fitting for carbon buildup and clean as needed using a wire brush or small scraper. Ensure both mating surfaces are clean and flat.
7. 7

   Inspect and clean fittings
   Inspect the exhaust manifold studs for damage or excessive corrosion. If studs are damaged, they must be replaced before proceeding. Check the carburetor spacer EGR fitting threads by attempting to thread the compression nut on by hand; it should turn smoothly without binding. If threads are damaged, the spacer may need replacement or thread repair.
8. 8

   Install new flange gasket
   Position the new EGR tube flange gasket over the two studs on the exhaust manifold EGR port. Ensure the gasket is properly oriented with any locating tabs or holes aligned.
9. 9

   Route and position new EGR tube
   Carefully maneuver the new EGR tube into position, following the same routing path as the original. Align the flange end over the exhaust manifold studs and gasket. Position the upper end near the carburetor spacer fitting but do not connect yet.
10. 10

    Install flange nuts finger-tight
    Thread the 2 flange nuts onto the exhaust manifold studs by hand, ensuring they thread smoothly without cross-threading. Tighten finger-tight only at this stage to allow for alignment adjustment.
11. 11

    Connect EGR tube to carburetor spacer
    Insert the upper end of the EGR tube into the carburetor spacer fitting. Thread the compression nut onto the spacer fitting by hand, ensuring it starts smoothly without cross-threading. Tighten the nut hand-tight, then use a 5/8" wrench to snug the connection. Do not fully torque yet.
12. 12

    Install support bracket
    Position the EGR tube support bracket and install the mounting bolt. Tighten the bolt to secure the bracket and provide proper tube support. This helps maintain alignment and prevents vibration damage.
13. 13

    Torque exhaust manifold flange nuts
    Using a torque wrench and 9/16" socket, torque the 2 exhaust manifold flange nuts in an alternating pattern to the factory specification (verify against a Ford service manual for this specific application before final tightening). This ensures even sealing pressure on the gasket.
14. 14

    Torque carburetor spacer compression fitting
    Using a 5/8" wrench, tighten the compression/tube fitting nut at the carburetor spacer to the manufacturer-specified value if available, otherwise snug it firmly (typically hand-tight plus a partial turn). Avoid over-tightening which can damage the brass fitting or strip threads.

Reassembly

1. Reconnect negative battery cable
2. Verify all EGR tube connections are secure and properly torqued
3. Ensure no tools or parts have been left in the engine compartment

Verification

• Start the engine and allow it to reach operating temperature while monitoring for exhaust leaks at the EGR tube flange connection
• Listen for hissing or exhaust noise from the tube connections; any leak indicates improper sealing or loose fittings
• With engine at operating temperature, visually inspect the entire EGR tube for signs of exhaust gas leakage (sooting or discoloration)
• Check that the EGR tube is not contacting any moving components or excessively vibrating
• Verify proper EGR system operation by confirming smooth idle and no rough running conditions

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