Preparing Your Classic Car for Winter Storage: A Guide to Protecting Your Car

For a much-loved classic, storing the car away for several months involves more than simply cleaning it, parking it in the garage and putting a cover over it. Proper preparation can help protect the bodywork, engine and mechanical components, keeping the vehicle in good condition and ready for that first sunny spring drive.

One area that should not be overlooked is the cooling system.

Why is winter preparation important for your classic or vintage car?

Classic and vintage cars can spend considerably more time stationary than modern daily vehicles. During storage, they remain exposed to changes in temperature and humidity, making proper preparation particularly important.

Before putting your car away for the winter, it is worth carrying out a thorough inspection and addressing any maintenance issues rather than leaving them until spring, when they could potentially develop into more costly or troublesome problems.

Basic winter storage preparation should include:

• Thoroughly cleaning and drying the exterior to remove dirt, salt and contaminants.
• Checking the engine oil and other essential fluids.
• Inspecting the cooling system for leaks, damaged hoses and other components.
• Checking the condition and level of the coolant.
• Checking the radiator and all connections.
• Maintaining the battery.
• Checking and adjusting tyre pressures, and inspecting tyres for cracks, splits or deterioration.
• Protecting the interior from moisture.
• Storing the vehicle somewhere dry and suitably ventilated.
• Using an appropriate breathable cover.

While these checks may be second nature to many classic car owners, coolant maintenance is one area that can easily be overlooked before winter storage.

Coolant does more than prevent an engine from overheating

Conventional water-based engine coolant with antifreeze provides protection against freezing and boiling. However, water-based coolants can deteriorate over time as its protective additives become less effective.

As this happens, the cooling system can become more vulnerable to corrosion, scaling and deposits. For classic and vintage vehicles, this is particularly important as radiators, hoses, gaskets, water pumps and other cooling-system components may already have experienced decades of use.

Maintaining the condition of the coolant is therefore an important part of protecting the cooling system and the engine.

How old is the coolant in your classic?

If you cannot remember when the coolant was last changed, winter preparation is a good opportunity to check its condition.

Coolant does not remain at peak performance indefinitely. As the fluid ages, its chemical protection can reduce, potentially leaving the cooling system more vulnerable to corrosion and temperature-related problems.

The recommended replacement interval will depend on the vehicle, coolant and manufacturer's recommendations. However, for a classic or vintage vehicle that may only cover a relatively small number of miles each year, it can be easy to overlook coolant maintenance.

Mileage isn't the only consideration — age and condition matter too.

What happens if coolant levels are low?

Before putting your car into storage, check the coolant level. A reduced coolant level can indicate a leak somewhere in the cooling system, such as the radiator, hoses or connections. It is important to investigate the cause rather than simply topping up the system and forgetting about it.

A cooling system that isn't operating correctly can leave an engine vulnerable to freezing during storage and overheating when the vehicle returns to the road. Low coolant levels can also contribute to vapour formation, cavitation and pitting, potentially causing damage to components such as the water pump and cylinder liners.

Winter temperatures and your cooling system

Freezing temperatures are an obvious concern when storing a vehicle through winter.

Water expands as it freezes, which can place significant stress on an inadequately protected cooling system if temperatures fall sufficiently low. This is one reason why maintaining the correct level of antifreeze and freeze protection is so important.

But winter protection isn't the only consideration.

The coolant sitting inside the engine during storage still needs to provide protection for the cooling system, while the same fluid will need to perform effectively when the vehicle is eventually brought back onto the road.

Winter storage therefore provides a good opportunity to look beyond simply asking, “Will it freeze?”

Could waterless coolant be a better option for your classic?

For classic and vintage car owners looking for long-term cooling-system protection, switching from conventional water-based coolant to a waterless coolant is another option worth considering.

Hawk Waterless Coolants use a waterless formulation designed to remove water from the cooling system. This helps avoid water-related issues such as corrosion and scaling, while also reducing the potential for steam formation under extreme operating temperatures.

For older vehicles, where protecting existing cooling-system components is an important part of maintaining the car for the long term, this can offer an alternative to conventional water-based coolant.

Protection through winter and beyond

Waterless coolant protection doesn't stop when the car is parked for winter.

Hawk Waterless Coolants are designed to operate across a wide temperature range, with a boiling point above 180°C and a freeze point of -40°C. This provides protection during storage while also allowing the coolant to remain in the vehicle when it returns to the road.

Unlike conventional water-based cooling systems, there is no water present in the Hawk formulation to contribute to the water-related corrosion and scaling issues associated with traditional coolant systems.

For classic and vintage vehicles that may spend months in storage and then be expected to perform reliably when back on the road, long-term cooling-system protection can be an important consideration.

Don't simply drain and refill

If you decide to convert your classic to Hawk Waterless Coolant, correct preparation is essential.

Waterless coolant should not simply be poured into a cooling system containing significant amounts of conventional water-based coolant. The existing coolant and residual water need to be properly drained as part of the conversion process.

Hawk Prep Fluid is used during the conversion process to help remove residual water before the system is filled with Hawk Waterless Coolant. The cooling system should also be inspected for leaks and any existing problems addressed before conversion.

Once correctly converted and maintained, Hawk Waterless Coolants are designed to remain in the cooling system for up to 20 years without routine coolant replacement.

Give your classic a head start on spring

Winter storage is the perfect opportunity to give your classic car the attention it deserves. Checking the vehicle thoroughly, addressing existing problems and ensuring the cooling system is properly protected can help avoid unwanted issues when spring arrives.

It's easy to concentrate on what you can see — the paintwork, chrome, interior and tyres — but don't forget about what is happening beneath the bonnet. Your cooling system remains an important part of protecting your engine, even when your car is sitting in storage.

If your classic or vintage car is still running conventional water-based coolant, winter preparation could be the ideal time to consider converting to Hawk Waterless Coolant for ultimate protection from corrosion, freezing, pre-ignition and boil over.

Designed for classic and vintage applications, Hawk provides up to 20 years cooling-system protection, with no need for replacement, and a freeze point of -40°C and boiling point above 180°C.

Protect your classic this winter — and be ready for the road ahead.

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