COOLING SYSTEM: Let's move on now to the cooling system. As we can see in the diagram, the water pump, located where the fan connects to the engine itself, pulls the coolant from around the engine's cylinder cooling jackets and head casting passages and forces it through the upper radiator hose and into the radiator where it is cooled by the radiator fan. The thermostat regulates the amount of coolant to be cooled. From the radiator, the coolant then passes through the lower hose before flowing back to cool the engine once again. Periodic cooling system maintenance involves flushing the radiator and checking for leaks around the hoses and radiator itself. The first thing to check in your cooling system is the level of the coolant reservoir. If the level is below the specified recommendations for your car, add a 50/50 mixture of coolant and water to the proper level. If heater radiator or vacuum hoses are particularly soft,. brittle, squishy, bulgy, cracked or leaking, have them replaced. Hoses should have a solid, firm feel. If you suspect an intake air leak is causing your car to run poorly and idle improperly, what you need to do is remove the air box, take a can of WD-40 aerosol spray and spray in the vicinity of the carburetor and intake manifold listening for changes in idle speed. When you find a change in the idle speed, you know you have found the source of your leak.
