Radiators are often punctured when vehicles are operating in wooded areas. When this occurs—
- Cut the cooling fins and push them away from the leaking tubes.
- Cut the leaking tube in half and fold the ends of the tube back approximately three-fourths of an inch.
- Close the tube ends by pressing them flat with pliers.
Cooling system efficiency is reduced when several tubes are cut, causing the engine to overheat. When field expedient radiator repairs are made, loosen the radiator cap. This keeps the radiator pressure from building up and breaking the repair. High strength polymer kits are included in the crew and maintainer kit to cover the damaged core tubes after bending them over. Ensure the damaged area is very clean before applying polymer agents to ensure proper bonding. When these products are properly applied and cured, the radiator cap can be installed. Radiator sealer should be added after any major repairs are made to ensure small holes are sealed.
Source: U.S. Army FM 4-30.31, Recovery and Battle Damage Assessment and Repair