Replace the plastic coolant tank on a car by waiting until it is cool and releasing the pressure slowly if it is pressurized. Disconnect any hoses leading to the radiator and remove the old unit. Attach the new unit to the mounting bracket and clamp the hoses in place. Refill the unit with coolant and replace the cap.
This plastic tank helps to prevent the loss of coolant when the engine is warm. As of 2015, most of the tanks do not operate under pressure, but in vehicles from the 1990s, they sometimes operate under pressure. Pressurized tanks have a standard radiator cap while those operating at atmospheric pressure have a simple plastic cap. Never open the pressurized cap when the vehicle is hot to prevent scalding burns.
While replacing a leaking coolant tank is the best option, several manufacturers offer repair kits for fixing small cracks in the plastic. If the vehicle is under warranty, check the manufacturer’s literature to ensure use of such products does not void the warranty.
Leaking coolant tanks should be repaired as quickly as possible. The leak can cause the vehicle to overheat, resulting in the need for expensive repairs to the engine of the vehicle. If the vehicle overheats, pull to the side of the road immediately and follow the directions in the owner’s guide to cool the engine. Calling a tow truck is often necessary.