Coolant Reservoir

Replace or install the coolant overflow reservoir on a 1972 Ford F-100 with 302ci V8 engine, including hose routing and coolant system check.

Warnings

Tools required

Parts

• Coolant reservoir × 1 — Use OEM specification
• Radiator overflow hose × 1 — 5/8 inch ID rubber hose
• Hose clamps × 2 — 5/8 inch worm gear clamps

Fluids

• Ethylene glycol green 50/50 — 1 qt

Preparation

1. Ensure engine is completely cold to the touch
2. Park vehicle on level ground and engage parking brake
3. Place drain pan under radiator area to catch any coolant spillage
4. Locate the radiator cap and existing overflow tube on the radiator neck

Procedure

1. 1

   Remove old reservoir (if equipped)
   If an existing coolant reservoir is installed, locate the mounting bracket on the inner fender or radiator support. Remove the mounting fasteners securing the reservoir bracket to the body. The reservoir is typically held by 2 bolts or sheet metal screws. Use a Phillips or flathead screwdriver as appropriate. Disconnect the overflow hose from the radiator neck by loosening the hose clamp and sliding it off the radiator overflow tube.
2. 2

   Drain residual coolant
   Tilt the old reservoir to drain any remaining coolant into your drain pan. Inspect the overflow hose for cracks, brittleness, or deterioration. If the hose shows any signs of wear, replace it with new 5/8 inch ID rubber hose of appropriate length.
3. 3

   Clean mounting area
   Use a wire brush and shop rag to clean the mounting surface on the inner fender or radiator support where the new reservoir will be installed. Remove any rust, debris, or old coolant residue. Clean the radiator overflow tube nipple on the radiator neck with a rag.
4. 4

   Position new reservoir
   Position the new coolant reservoir in the desired location, typically on the driver side inner fender or radiator support. The reservoir should be mounted at approximately the same height as the radiator cap, or slightly lower, to allow proper overflow and recovery function. Ensure the reservoir cap will be accessible and the reservoir is positioned so the overflow hose from the radiator can drain into it without kinks.
5. 5

   Secure reservoir mounting bracket
   Mark the mounting hole locations on the body using the reservoir bracket as a template. Drill pilot holes if necessary for self-tapping screws, or use existing holes if available. Secure the reservoir bracket using 2 sheet metal screws or bolts with washers. Tighten securely but do not overtighten and crack the mounting bracket.
6. 6

   Connect overflow hose to radiator
   Route the overflow hose from the radiator overflow tube nipple to the inlet fitting on the top of the reservoir. Cut the hose to appropriate length, allowing for a gentle curve without kinks. Slide a hose clamp over the hose end, then push the hose firmly onto the radiator overflow tube nipple at least 1 inch. Position the clamp over the hose connection and tighten securely with a flathead screwdriver or pliers.
7. 7

   Connect hose to reservoir
   Attach the other end of the overflow hose to the inlet fitting on the reservoir cap or neck. Slide a hose clamp over the hose, push the hose onto the fitting at least 1 inch, and tighten the clamp securely. Ensure all hose routing avoids contact with moving parts, sharp edges, or hot exhaust components.
8. 8

   Install overflow drain tube
   If the reservoir has a bottom overflow outlet, attach a short length of hose to direct overflow coolant safely to the ground, away from belts and exhaust. This tube should hang freely below the vehicle frame.
9. 9

   Fill coolant system
   Remove the radiator cap. Fill the radiator with ethylene glycol green 50/50 coolant to the base of the filler neck. Fill the reservoir approximately one-third full, or to the COLD/MIN fill line if the aftermarket reservoir is marked. Install the radiator cap by pressing down and turning clockwise until it locks. Install the reservoir cap securely.
10. 10

    Bleed air from system
    Start the engine and allow it to reach normal operating temperature with the heater set to maximum heat. Monitor the temperature gauge to ensure the engine does not overheat. As the thermostat opens and air bleeds from the system, the coolant level in the reservoir may drop slightly. Shut off the engine and allow it to cool for 15 minutes.
11. 11

    Check and top off coolant
    Once the engine has cooled, check the coolant level in the reservoir. It should be at or slightly above the COLD fill line. Add coolant to the reservoir if needed. Do not remove the radiator cap while the system is hot. Check all hose connections for leaks and tighten clamps if necessary.

Reassembly

1. No disassembly required beyond reservoir removal
2. Ensure all hose clamps are positioned over hose connections and tightened securely
3. Verify hoses are routed away from moving parts and hot components

Verification

• With engine cold, verify coolant level is at COLD fill line on reservoir
• Start engine and verify no leaks at hose connections or reservoir mounting points
• Allow engine to reach operating temperature and verify coolant circulates into reservoir as system pressurizes
• After engine cools, verify coolant is drawn back into radiator from reservoir
• Check that reservoir coolant level rises slightly when engine is hot and falls when cold
• Inspect ground under vehicle for any coolant drips after test drive

More procedures for this vehicle