how do I replace my 2005 fiesta expansion header tank
Coolant is old.
through the reserve tank which is also called the overflow tank being that there is no radiator cap!
The "check coolant level" message will come on when the coolant level is low in the overflow tank. If the message stays on after the tank is filled, make sure the sensor on the front bottom is connected. If the connection is O.K., then lightly tap on the side of the overflow tank with a soft rubber mallet. If the message persists after driving the car a couple of days, replace the overflow tank.
An overflow tank is a bottle that holds coolant that expands and leaves the radiator under driving conditions. The Coolant will go back into the radiator as needed.
A coolant overflow tank and a radiator overflow bottle serve similar purposes but are distinct components. The coolant overflow tank is designed to collect excess coolant that expands from the radiator when the engine heats up, preventing pressure buildup. In contrast, the radiator overflow bottle typically refers to a specific type of tank that captures overflow from the radiator directly, allowing for the coolant to return to the system as it cools. Both components help maintain the proper coolant level, but they may be used in different cooling system designs.
red
in the overflow tank
The overflow tank is either cracked or its overheating and leaking from the cap
Its either in the coolant overflow tank or in the side of the radiator
The overflow tank for coolant will "boil" if there is air getting in the coolant chamber. This can be a head gasket going bad.
Usually a blown head gasket.
Add it in the overflow tank up to the max line.