Radiator Replacement

The radiator is the primary component of the cooling system and is responsible for keeping the temperature of the coolant at a cooler temperature by venting heat produced by the engine. If the vehicle is equipped with an automatic transmission, the radiator is also responsible for keeping the temperature of the transmission fluid cool, so that the transmission doesn't get too hot and overheat.

The radiator’s work is accomplished by heat transfer. As the power of the engine increases, the radiator removes more heat. The position of the radiator is important. Radiators are located at the front of the vehicle to maximize air exposure. At higher speeds and during acceleration more air enters through the grill that is attached to the front bumper, thereby aiding in the transfer of heat.

Radiators can fail due to three possible circumstances, including leaks, internal restriction due to rust build up, or the built in automatic transmission cooler can leak transmission fluid into the radiator and mix with the coolant, producing a foamy reddish-pink fluid that resembles a strawberry milkshake. If the fluids mix, you will need to flush the transmission too, and hope it is not damaged.

There are two basic designs of radiators used on automotive vehicles: down-flow and cross-flow radiators.

Down-flow radiators are used mostly in older vehicles. These radiators are considered down-flow because the coolant enters the radiator at its top and the coolant travels downward exiting the radiator at its bottom.

Cross-flow radiators are found on the majority of vehicles on the road. These radiators are named cross-flow because the coolant enters the radiator on one side and travels across the radiator--exiting it on the other side.

Although, pinpointing a problem with the radiator and performing a complete coolant system diagnostic should always be the first step before attempting to swap radiators out. The following are step-by-step instructions for changing out a radiator.