How to Install a Coolant Expansion Tank on a 2000 BMW 323i
Removing the Existing Tank 1. Let the engine and radiator cool down completely. Open the hood and support it in a raised position. 2. Pull the electrical wiring harness from the back side of the air filter housing on top of the engine. Unsnap the two connectors on the intake hose on the back side of the air box. Remove the two retaining bolts on the driver’s side of the housing with a socket and ratchet. Lift the housing up and remove it from the engine bay. 3. Remove the retaining screws on the engine cover on the underside of the car with a Phillips screwdriver. Rotate the cover downwards so that you can access the underside of the radiator and expansion tank. 4. Remove the pressurized cap from the expansion tank slowly and place it aside. Place a clean drain pan under the driver’s side of the radiator. Remove the drain plug on the bottom of the radiator with a wrench. Replace and tighten the plug after all the coolant has drained from the radiator. 5. Unplug the...