16 Common Radiator Failures

Solder Bloom – Solder corrosion caused by degradation of rust and leak inhibitors in antifreeze. Tube-to-header joints are weakened, and corrosion can restrict coolant flow. Internal Deposits – Rust and leak inhibitors can form solids that collect in the cooling system and restrict flow.
Fin Deterioration – A chemical deterioration of the fins most often caused by road salt or sea water. Fin Bond Failure – A loss of solder bond between fins and tubes. Fins are loose in core causing loss of heat transfer and reducing radiator strength.
Tube-To-Header Leaks – Failure of the solder joint results in coolant loss. Leaky Tank-To-Header Seam – Solder joint failure or a cracked header is generally the result of pressure-cycle fatigue.
Blown Tank-To-Header Seam – An indication that the radiator has been subjected to extreme pressures resulting from exhaust leaking into the cooling system. Loose Side Piece – Can lead to flexing of the core and radiator tube failure.
Leaky Oil Cooler – Coolant shows traces of oil. Transmission or engine damage can result from the mixing of coolant with transmission fluid or engine oil. Leaky Inlet/Outlet Fitting – Leaks in this area can be caused by fatigue or solder joint corrosion.
Fan Damage – A minor collision or a failed water pump can result in radiator damage. Over Pressurization – Excessive pressure in the radiator caused by a defective pressure cap or engine exhaust leak can destroy the radiator.
Electrolysis – Stray electrical current can cause excessive corrosion of metal components. Electrolysis – Stray electrical current can cause an electrochemical reaction that will produce voids in tubes.
Cracked Plastic Tanks – High stress in the radiator can cause premature plastic tank failure. Steam Erosion – Steam can break down the plastic tank which will produce thinning and, ultimately, holes in the plastic tank. Frequently, white deposits are also found.