The radiator overflow will not return even after the motor has cooled in my Mitsubishi Pajero.

Question

This problem occurs when under load, mainly. The fluid will not return when the vehicle cools. The radiator stays at positive pressure inside. The low coolant level beeper, will sound until I pour the fluid back into the radiator.

Answer 1

The return coolant isn't the problem. Air in the radiator is the problem. If the return tank has coolant in it then air must be getting into the radiator some other way. Like a bad cap, a leak or a bad head gasket.  

Answer 2

change the radiator cap.

Answer 3

what problem??? the fluid will not return if the rad is under pressure, thats normal if the engine is warm. If the cars pushing out coolant under load,could be alot of things from a plugger rad to a leaking head gasket. A leaking hose connection could cause the system to suck in air some place when cooling down instead of from the coolant recovery tank. Does the car over heat?  Not enough info to help much sorry.

Answer 4

If it has a cap replace it with a factory replacement>

Answer 5

NEED NEW CAP ON RADIATOR

Answer 6

The rad. should work like this, when the engine is hot pressure pushes coolant out into the tank, when the engine cools down the coolant is pulled bak into the rad. If the Rad. cap is bad that cpould be the cause, if the Rad. cap is good and working as it should. The cause may be a leak in the system preventing coolant from being pulled bak into the Rad.Another cause could be the engine is runnnig hot or the Rad. cooling inop.