Radiator fluid is part of a vehicle's cooling system that draws heat away from the engine. Radiator fluid leaks can result from a number of problems, such as bad seals, damaged hoses and bad head gaskets.
Most leaks can be visually detected and the radiator should be the first area inspected. Loose hose connections, internal corrosion and damage from stones can cause leaks. Hoses that develop splits or holes from deterioration or damage will let fluid escape. Corroded clamps may also allow leaks by not keeping a hose properly sealed.
A water pump is attached to the engine block behind the radiator; if it leaks fluid this is usually the result of a bad seal on or inside the pump. Freeze plugs are in the side of the engine block and can leak coolant if they become corroded. Heater cores connect to the cooling system to deliver heat inside the vehicle; if cores or their hoses fail, radiator fluid will leak, often inside the vehicle. Head gaskets are between the engine block and the cylinder head and a defective one can allow coolant to enter the intake port and crankcase or drip down the outside of the engine.
Fluid leaks that occur internally are hard to detect because they happen inside the engine. They also are very expensive to repair. Internal leaks usually are due to a bad head gasket or a cracked cylinder head or block. Bad head gaskets are the most common cause and could contribute to mixing coolant and engine oil which can lead to damage of the bearings or fouling of spark plugs. Leaks from cracked heads or blocks can lead to damage of the pistons and rings.
