A cooling system bleeder screw is used to

A cooling system bleeder screw is used to

• A. Release air trapped in the cooling system
• B. Increase coolant flow
• C. Open the radiator cap
• D. Reduce coolant pressure

Answer: (D)

A cooling system bleeder screw is used to vent air trapped in the cooling system. When you refill the system, air rises to the high spots and can form air pockets that block coolant flow and cause overheating. Opening the bleeder at a high point lets that air escape so coolant can fill the system fully. Once a steady stream of coolant (without air bubbles) flows out, you close the bleeder. This ensures proper circulation and pressure within the cooling system. It isn’t meant to increase flow directly, open the radiator cap, or reduce coolant pressure.

A cooling system bleeder screw is used to vent air trapped in the cooling system. When you refill the system, air rises to the high spots and can form air pockets that block coolant flow and cause overheating. Opening the bleeder at a high point lets that air escape so coolant can fill the system fully. Once a steady stream of coolant (without air bubbles) flows out, you close the bleeder. This ensures proper circulation and pressure within the cooling system. It isn’t meant to increase flow directly, open the radiator cap, or reduce coolant pressure.