The radiator surge tank is a black plastic tank through which you fill the cooling system. The surge tank is mounted higher than all the other coolant passages. This provides an air bleed source for the cooling system. Maintain the coolant level in the surge tank to the base of the filler neck.

Coolant Recovery Reservoir

A semi-transparent plastic reservoir connects to the radiator surge tank with a hose. During vehicle use, the coolant heats and expands. Fluid, displaced by this expansion, flows from the radiator surge tank into the recovery reservoir. When the coolant cools and contracts, vacuum draws the displaced coolant back into the radiator surge tank. Any air or vapor in the cooling system is forced to the reservoir and escapes through the vent on the cap of the reservoir.

You can add coolant to the recovery reservoir without removing the filler cap from the surge tank. Maintain the coolant level between the COLD and HOT marks on the cap level indicator of the reservoir.