How to Replace a 2001 Audi A4 Quatro Radiator

1. Pop the hood on the car and make sure the engine is completely cool before you start. Even a slightly warm engine could result in serious burns. Disconnect the negative cable on the battery using a wrench to loosen the nut on the terminal. Place a drain pan under the radiator and drain the engine coolant by opening the valve on the bottom of the radiator with a wrench. Remove the engine undercover using a screwdriver.
2. Note the proper routing of the accessory drive belt and remove it by turning the idler pulley counter clockwise using a wrench. Remove the power steering pump using a wrench. Remove the secondary air pump and the bracket using a wrench to remove the bolts. Disconnect the radiator hoses using the screwdriver to loosen the hose clamps.
3. Unplug the wiring harness from the radiator fan. Place the wheel chocks behind the rear wheels of the Quattro. Lift the front end of the car using the automobile jack. Place a jack stand under the Audi near the jacking point and raise it to the frame. Remove the bolts from the mounting brackets using a wrench. Lower the radiator and fan together from the Audi.
4. Remove the fan unit from the old radiator and connect it to the new one. Install the radiator and fan unit together from the bottom of the car. Mount it in place by tightening the bracket bolts with a wrench. Remove the jack stand from under the Audi and lower the car to the ground. Plug the wiring harness into the fan unit.
5. Connect the radiator hoses and tighten the hose clamps with the screwdriver. Install the secondary air pump and brackets and secure it using a wrench. Install the power steering pump and tighten the mounting bolts with a wrench. Reinstall the accessory drive belt and tighten it by turning the idler pulley clockwise with the wrench.
6. Install the engine undercover using a screwdriver. Connect the negative battery cable and tighten the terminal nut with the wrench. Refill the radiator and reservoir with fresh engine coolant. Start the Audi and check the system thoroughly for leaking.