Removing the radiator from a Cadillac STS is a job that can be completed in a couple of hours by most home mechanics. Occasionally, the radiator can become corroded or develop cracks in the metal due to severe pressure building up inside. The STS's radiator is located directly behind the front grill and is very accessible. Removing the radiator yourself saves time and money vs. taking your vehicle to a radiator shop.
Unfasten the negative battery cable of the Cadillac STS from the battery post with an open-end wrench. Locate the drain valve at the bottom of the radiator and place a drain pan underneath the drain valve.
Remove the radiator cap from the top of the radiator. Take the cap off the coolant overflow reservoir on the passenger side of the engine compartment. Open the drain valve at the bottom of the radiator with a pair of pliers and allow the radiator to drain completely into the drain pan.
Unfasten the screw clamps on the upper and lower radiator hoses with a screwdriver. Pull the hoses off the radiator flanges, using a screwdriver to pry them off the radiator.
Disconnect the transmission cooling line from the back of the radiator near the bottom, using an open-end wrench to remove the line. Pull it away gently from the radiator by hand, just enough so it doesn't get hung up when you remove the radiator.
Unfasten the cooling fan cover mounting bolts from the vehicle frame with a socket wrench. Disconnect the cooling fan electrical wiring plug from the electrical connector by hand.
Detach the radiator mounting bolts from the vehicle frame with a socket wrench. Lift the radiator out of the Cadillac STS engine compartment and set it out of the way.
