In this video you will learn how to tighten radiator valves using a spanner and water pump pliers. If you find that your radiator valves are leaking, follow these simple steps to remedy the situation: If you take a look at your lock shield valve, you may see signs that it has been leaking. Grip the valve with a pair of water pump pliers. This will prevent you from breaking the copper pipe. Tighten in a clockwise direction. Feel with your fingers to make sure there are no more leaks.