2. The cooling system should be checked on a cold engine. Do this the day before using the car and no sooner than three hours after stopping the engine.
3. Remove the radiator cap by turning it to the left until it stops. If you hear a hissing sound (indicating that the system is still under pressure), wait a while until the hissing stops. Then press the cap with your palm and continue turning it to the left until you can remove it. Rinse the cap inside and out with clean water. Wipe the radiator filler neck as well. Any traces of corrosion should be removed. The coolant in the radiator should be relatively clear. If it is rusty, it should be drained and the system filled again (section 3). If the fluid level does not reach the top, top it up to the norm (see section 4).
4. Carefully inspect the large upper and lower radiator hoses, as well as the smaller diameter heater hoses that run from the engine to the bulkhead. Inspect all hoses along their entire length, replacing any that are cracked or damaged. Cracks become more noticeable if the hose is compressed. Regardless of the condition of the hoses, it is a good idea to replace them every two years.
5. Make sure all hoses are tightly connected. Coolant system leaks usually show up as a white or rust-colored coating in areas near the leak. If the ends of the hoses have wire clamps, it is best to replace them with more secure screw clamps.
6. Use compressed air to remove insects, leaves, etc. from the front of the radiator or air conditioning condenser. Be careful not to damage or cut yourself on the thin cooling fins.
7. During each inspection or at the first sign of a cooling system problem, check the cap and the pressure in the system. If you do not have the appropriate pressure gauge, most auto repair centers will do this for a minimal fee.