Cooling system sort-out

Sort out your engine’s cooling system in a weekend.

How to flushing your classic cooling system.

T he cooling system prevents your engine overheating and many of us adopt the principle of ‘If it ain’t broke, don’t fix it.’ However, the coolant should be renewed every two years (some modern coolant can last for five years) and at the same time, it helps to flush the system through to remove any silt and corrosion.

When a coolant mixture becomes old, it loses its ability to prevent corrosion, so any steel components within the cooling system (coolant pipes, engine block) can start to corrode.

Mix this with deposits of dirt and any rubber hoses that break down, and the cooling system can soon become clogged.

Draining the coolant, flushing through the system and refilling it can take less than one hour on most cars. However, it’s worthwhile spending a little more time flushing through individual components and if possible, removing them. This can help to identify problems, such as a blocked expansion bottle or a clogged up thermostat.

The following pages provide several general step-by-step guides showing how to quickly flush a coolant system, remove components such as the radiator, expansion bottle and heater, along with advice on refilling and bleeding a coolant system, changing a pressure cap and checking the water pump.