When draining a cooling system, the used coolant must be captured in a bucket and disposed of correctly. Coolant contains toxins that are harmful to the environment and poisonous if ingested. Care should be taken when handling this waste water, only transport in sealed containers; it is advisable you contact your local council on the location of a facility to take the waste water.
In order for coolant to properly absorb heat from the engine and prevent overheating, it must remain below a certain temperature. Check your vehicles owners’ manual on the specific type of coolant to use in your cooling system. There are many different additives in coolant so it is very important to use the correct one. Some additives protect alloy and others may stop your water from freezing so be sure to check because radiators are responsible for transferring heat from a vehicle's coolant to the outside air.
Some manufacturers provide radiator caps with temperature gauges built into them. Cap gauges are useful in case of temperature sensor failure. Also, being able to read an approximate temperature while the vehicle is operating provides information about how effectively the coolant is absorbing heat and how hot the engine is running. When driving it is a good practise to no your vehicles operating temperature in relation to the temperature gauge, if the temperature gauge raises suddenly you no you may have a problem in your cooling system.