Radiator Hose - Lower

This procedure covers removal and replacement of the lower radiator hose on a 1972 Ford F-100 with 302ci V8 engine, including coolant draining and refilling.

Warnings

Tools required

Parts

• Lower radiator hose × 1 — Use OEM specification for 302ci V8
• Hose clamps (worm-gear type) × 2 — 1.25-1.5 inch diameter

Fluids

• Ethylene glycol green 50/50 coolant — 15 qt

Preparation

1. Ensure engine is completely cold to the touch
2. Park vehicle on level ground and set parking brake
3. Place drain pan under radiator drain petcock (located at bottom driver side of radiator)
4. Have shop rags ready to catch residual coolant spillage

Procedure

1. 1

   Drain cooling system
   Open the radiator drain petcock by turning counterclockwise. If petcock is seized or missing, carefully loosen the lower radiator hose clamp at the radiator end and allow coolant to drain into the pan. Remove the radiator cap to allow faster draining. Drain until coolant level is below the lower radiator hose connection points.
2. 2

   Remove lower hose clamp at radiator
   Locate the lower radiator hose connection at the bottom driver side of the radiator. Using a flathead screwdriver, loosen the worm-gear hose clamp by turning the screw counterclockwise. Slide the clamp down the hose away from the radiator neck.
3. 3

   Disconnect hose from radiator
   Twist the hose back and forth while pulling to break it free from the radiator outlet neck. If the hose is stuck, carefully insert a flathead screwdriver between the hose and neck to break the seal. Be careful not to damage the radiator neck. Have rags ready to catch residual coolant.
4. 4

   Remove lower hose clamp at water pump
   Locate the lower radiator hose connection at the bottom of the water pump (passenger side of engine block). Loosen the worm-gear hose clamp by turning the screw counterclockwise with a flathead screwdriver. Slide the clamp down the hose away from the water pump inlet.
5. 5

   Disconnect hose from water pump
   Twist the hose back and forth while pulling to remove it from the water pump inlet. If stuck, carefully use a flathead screwdriver to break the seal between hose and inlet. Remove the complete lower radiator hose from the vehicle.
6. 6

   Clean connection surfaces
   Inspect both the radiator outlet neck and water pump inlet for corrosion, damage, or old rubber residue. Clean both surfaces with a rag. If old hose material is stuck to the necks, carefully scrape it away with a utility knife without gouging the metal surfaces.
7. 7

   Install new hose clamps on new hose
   Slide both new worm-gear hose clamps onto the new lower radiator hose before installation. Position one clamp near each end of the hose, with the screw mechanisms accessible for tightening.
8. 8

   Connect new hose to water pump
   Push the lower end of the new radiator hose firmly onto the water pump inlet until it bottoms out against the stop bead on the inlet neck. The hose should be seated approximately 1.5 to 2 inches onto the inlet. Position the hose clamp over the connection point, approximately 0.25 inch from the end of the inlet neck, and tighten the screw firmly with a flathead screwdriver until snug. Do not overtighten as this can cut the hose.
9. 9

   Connect new hose to radiator
   Route the upper end of the hose to the radiator outlet neck, ensuring the hose follows a smooth path without kinks or sharp bends. Push the hose firmly onto the radiator outlet neck until it bottoms out against the stop bead. Position the hose clamp over the connection point, approximately 0.25 inch from the end of the neck, and tighten firmly with a flathead screwdriver until snug.
10. 10

    Close drain petcock
    If the radiator petcock was opened, close it by turning clockwise until snug. Do not overtighten. Ensure it is fully closed to prevent leaks.
11. 11

    Refill cooling system
    Using a funnel, slowly pour ethylene glycol green 50/50 coolant mixture into the radiator until it reaches the bottom of the radiator neck. Pour slowly to allow air pockets to escape. The system capacity is approximately 13-14 quarts total (verify against factory specification). Fill until coolant is visible at the filler neck. Verified detail (The 302ci V8 cooling system capacity is approximately 14-15 quarts is too high; a 302 with heater is typically around 14 quarts, but 15 quarts is questionable. More importantly the figure needs verification against the FoMoCo spec — the 302 system is generally closer to 12-14 quarts. Flag for verification.): The system capacity is approximately 13-14 quarts total (verify against factory specification for the 302ci V8).
12. 12

    Burp cooling system
    With the radiator cap still off, start the engine and allow it to idle. Watch the coolant level and add more coolant as the level drops while the thermostat opens and air is purged from the system. Squeeze the upper radiator hose several times to help release trapped air. Continue running until the engine reaches normal operating temperature and the thermostat opens (coolant will begin circulating visibly in the radiator).
13. 13

    Final fill and cap installation
    With the engine still running, top off the coolant to the bottom of the radiator neck. Install the radiator cap securely. Allow the engine to continue idling for 2-3 minutes, then shut off the engine.

Reassembly

1. Check all hose clamp connections for tightness after the engine has cooled
2. Inspect the ground under the vehicle for coolant leaks after the first drive

Verification

• Visually inspect both hose connections at the radiator and water pump for leaks with the engine running at operating temperature
• Check coolant level in radiator after engine cools - top off if necessary
• Verify no coolant drips or puddles under vehicle after overnight parking
• Squeeze the lower radiator hose when engine is at operating temperature - it should feel firm from system pressure

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