The radiator on a Jeep Wrangler is mounted to the core support just in front of the engine. The radiator uses thin copper-brass tubes to draw heat off the coolant and lower the operating temperature of the engine. Because these tubes are thin, they are prone to corrosion. If your radiator begins to leak, you must remove it from the vehicle and take it to a radiator specialist to be pressure tested. They will be able to tell you if the radiator can be repaired or must be replaced.
Locate the petcock valve on the lower right corner of the radiator and place a waste oil collection pan underneath it.
Open the petcock valve by turning it counterclockwise, using needle nose pliers.
Wait until all the coolant has drained out then close the petcock valve by turning it clockwise.
Loosen the hose clamp that connects the upper radiator hose to the radiator using a Phillips head screwdriver. Then pull the upper radiator hose off the radiator.
Loosen the hose clamp that connects the lower radiator hose to the radiator using a Phillips head screwdriver. Then pull the hose off the radiator.
Unscrew the transmission cooler lines from the radiator (automatic transmission only) using a wrench.
Unscrew the bolts that secure the radiator to the core support, using a socket.
Lift the radiator straight up to remove it from the vehicle.
Lower the radiator into position behind the core support. Be careful: the cooling fins are thin and can be easily damaged.
Screw the bolts that secure the radiator into the core support. Tighten with a socket.
Thread the transmission cooler line fittings into the radiator. Tighten with a wrench.
Slide the lower radiator hose onto the fitting on the bottom of the radiator. Slide the hose clamp over the fitting and tighten with a Phillips head screwdriver.
Slide the upper radiator hose onto the fitting on the top of the radiator. Slide the hose clamp over the fitting and tighten with a Phillips head screwdriver.
Fill the engine with a 50/50 mix of antifreeze and water.
Run the engine and visually inspect for leaks.
