Hawk Prep Fluid 5L is specially formulated to prepare a cooling system prior to conversion to Hawk Waterless Coolants. Compatible with all engine types, it is an essential step when an engine contains or has previously contained conventional water-based cooling fluid.

After a standard drain, water may remain trapped in the engine block, cylinder head, radiator, heating system, or various pipes. Thanks to its hygroscopic properties, Hawk Prep Fluid absorbs this residual water and also helps flush out loose dirt and deposits present in the system. It thus prepares the engine before it is finally filled with the appropriate Hawk waterless cooling fluid.

Important: Hawk Prep Fluid is not the final cooling fluid. It is used during the conversion process and must be drained before refilling with the Hawk cooling fluid selected for the vehicle.

What is Hawk Prep Fluid used for?

The primary role of Prep Fluid is to minimize the quantity of water remaining in the system after draining. This step is essential to fully enjoy the benefits of a water-free cooling fluid.

Hawk recommends that , after conversion , the residual water content be ideally 3% or less. This concentration can be checked using a refractometer.

Proper preparation ensures that Hawk’s waterless cooling fluid will perform as intended and minimizes issues associated with the presence of water, such as localized boiling, vapor formation, oxidative corrosion, pressure in the cooling system, and cavitation.

The Benefits of Hawk Prep Fluid

• Preparation before switching to waterless coolant: specially developed for converting a cooling system to Hawk Waterless Coolants.
• Residual water absorption: its hygroscopic properties allow it to remove water remaining in the engine after a drain.
• Compatible with all engine types: allows you to prepare various cooling systems before selecting the Hawk fluid appropriate for the vehicle.
• Helps flush the system: helps remove loose dirt and deposits present in the cooling system.
• Water-free formulation: allows you to prepare the system without reintroducing water.
• Optimized preparation: helps achieve a residual water content of ideally 3% or less after conversion.
• Essential step in the conversion process: ensures that the Hawk cooling fluid used afterward fully retains the benefits associated with its water-free operation.

Features of Hawk Prep Fluid 5L

• Type: Cooling system preparation fluid
• Brand: Hawk Waterless Coolants
• Product: Prep Fluid
• Volume: 5 liters
• Application: Preparation prior to switching to a Hawk waterless cooling fluid
• Compatibility: All engine types
• Main function: Hygroscopic absorption of residual water
• Additional Action: Helps flush out loose dirt and deposits from the system
• Formulation: Water-free
• State: Low-viscosity synthetic liquid
• Boiling point: Above 180°C
• Freezing point: Below -40°C
• Recommended water content after conversion: Ideally 3% or less
• Water content check: Refractometer
• End use: Must be drained before final filling with the appropriate Hawk fluid
• Former brand name: Evans Waterless Coolants
• Former product name: Evans Prep Fluid

Why is it necessary to prepare the system before switching to a waterless coolant?

Simply draining the system does not always remove all the water present in a cooling system. Some of the oldcooling fluid may remain in the engine block, cylinder head, radiator, heater core, and certain pipes.

Filling the system directly with a waterless cooling fluid without properly removing this residual water is equivalent to contaminating the new cooling fluid as soon as it is put into service. However, the benefit of the Hawk system lies precisely in the removal of water and the issues associated with it.

Hawk Prep Fluid therefore serves as the intermediate step between draining the old coolant and filling the system with the new water-free coolant. Thanks to its hygroscopic properties, it absorbs the residual water present in the system. The Prep Fluid, now saturated with this water, is then drained.

The system can then be filled with the Hawk water-free cooling fluid appropriate for the vehicle, engine, and its intended use.

How do you use Hawk Prep Fluid during a conversion?

Start by draining as much of the old cooling fluid as possible. The Hawk Prep Fluid is then introduced into the system to absorb any water that could not be removed during this initial drain.

Once the preparation procedure is complete, the Prep Fluid must be completely drained. The system is then ready to receive the appropriate Hawk waterless cooling fluid.

After the conversion, Hawk recommends that the residual water content be ideally 3% or less. A refractometer can be used to check this value and verify the quality of the conversion.

Prep Fluid must not remain in the engine as the final cooling fluid. Its purpose is to prepare the cooling system before the final fill with a Hawk Waterless Coolant.

Which Hawk cooling fluid should you choose after using Prep Fluid?

Hawk Prep Fluid can be used to prepare various types of engines. However, once the cooling system has been prepared, the final cooling fluid must be selected based on the vehicle, the engine design, the materials used, and its use.

• Hawk Power Cool 180° 5L: for sports cars, tuned vehicles, race cars, and high-performance engines.
• Hawk Classic Cool 180° 5L: for classic and collector’s cars. As a general guideline, this formulation is primarily suited for vehicles from approximately 1950 to 1980. Engine design and system materials remain the primary factors in determining compatibility.
• Hawk Vintage Cool 180° 5L: for vintage and classic cars, generally applicable to vehicles up to the years 1950-1959. This formulation is particularly well-suited for older engines that use materials such as cast iron, copper, and brass.
• Hawk PowerSports R 5L: for street bikes, sport bikes, and racing bikes, particularly those with engines made primarily of aluminum.

The vehicle’s year of manufacture is only a general guide. For vintage and classic cars, engine technology and the materials used in the cooling system must also be considered before choosing between Vintage Cool and Classic Cool.

What are the benefits of switching to a Hawk water-free cooling fluid?

Preparation with Prep Fluid ensures the cooling system is properly converted to take full advantage of the properties of a Hawk waterless cooling fluid. The goal is to remove water from the system and reduce problems directly associated with its presence.

In the hottest areas of an engine, the water contained in a conventional cooling fluid can boil locally and form steam. These phenomena reduce heat transfer to metal surfaces and can create localized hot spots, promoting overheating conditions that can, in particular, contribute to a blown head gasket.

Depending on the Hawk formulation chosen, switching to a water-free coolant offers benefits such as a very high boiling point, low vapor pressure, reduced cavitation, and the absence of water-related oxidation corrosion. These properties help protect the engine, water pump, hoses, gaskets, radiator, and various components of the cooling system.

Evans Prep Fluid Becomes Hawk Prep Fluid

Evans Waterless Coolants is now known as Hawk Waterless Coolants. The product previously marketed as Evans Prep Fluid is now Hawk Prep Fluid. This change affects the brand identity only and does not alter the product’s formulation.

GT2i is an official retailer of Hawk Waterless Coolants. At GT2i, you’ll find Prep Fluid as well as the various Hawk formulations that allow you to tailor the waterless cooling fluid to your vehicle and its engine.

FAQ - Hawk Prep Fluid

What is Hawk Prep Fluid used for?
Hawk Prep Fluid is used to prepare a cooling system before converting it to a Hawk waterless coolant. Thanks to its hygroscopic properties, it removes residual water remaining in the engine after draining the old coolant.

Is Hawk Prep Fluid a cooling fluid?
Prep Fluid is a preparation fluid and is not intended to remain permanently in the engine. After the conversion process, it must be drained and replaced with the Hawk waterless cooling fluid appropriate for the vehicle.

Why isn’t a simple drain sufficient before switching to waterless coolant?
Even after draining the coolant, water may remain trapped in the engine block, cylinder head, radiator, heater, or certain lines. Prep Fluid helps remove this residual water to properly prepare the cooling system.

What quantity of water might remain after the conversion?
Hawk recommends that the residual water content ideally be 3% or less to fully benefit from the properties of the waterless cooling fluid.

How do you check the quantity of remaining water?
The water content can be checked using a refractometer. This measurement allows you to verify the quality of the water circuit preparation.

Does Hawk Prep Fluid clean the cooling system?
Its primary function isto absorb residual water. As it flows through the system, it also helps flush out loose dirt and deposits. However, it should not be confused with a product specifically designed for decoking or intensive cleaning of a heavily contaminated system.

Should the Prep Fluid be drained before adding the Hawk coolant?
Yes. The Prep Fluid must be drained after the preparation phase. The cooling system can then be filled with the Hawk water-free cooling fluid suitable for the engine.

Which Hawk coolant should be used after the Prep Fluid?
The choice depends on the vehicle and engine. Power Cool 180° is intended for sports cars and high-performance engines; Classic Cool 180° for classic cars from approximately 1950 to 1980; Vintage Cool 180° for older vehicles, specifically those dating back to the 1950s; and PowerSports R for street, sport, and racing motorcycles.

Why is it necessary to remove water before adding a Hawk coolant?
The goal of the Hawk system is precisely to operate without water. Reducing residual water helps limit the issues associated with its presence—including localized boiling, vapor formation, oxidation corrosion, and cavitation—and allows you to fully benefit from the properties of the Hawk fluid used afterward.

Can Hawk Prep Fluid be reused after a conversion?
The Prep Fluid collects residual water present in the system during preparation. Once used and saturated with water, it should not be considered a new Prep Fluid for performing another conversion.

Are Evans Prep Fluid and Hawk Prep Fluid the same product?
Yes. Evans Waterless Coolants has become Hawk Waterless Coolants. The former Evans Prep Fluid is now marketed under the name Hawk Prep Fluid. The formulation remains unchanged.

Hawk Classic Cool 180° 5L Waterless Cooling Fluid is specially formulated for classic and vintage cars, primarily those manufactured from approximately 1950 to 1980. It is particularly suitable for engines primarily constructed of cast iron and for cooling systems that also include steel, copper, and aluminum components.

Hawk Classic Cool 180° cooling fluid is used undiluted with water. Its boiling point, which exceeds 180°C, and its freezing point, which is below -40°C, help reduce issues related to water boiling, vapor formation, corrosion, and cavitation—features that are particularly beneficial for preserving the cooling systems of older vehicles.

Note: The years 1950 through 1980 serve as a guideline to help select the right product. Engine design and the materials used in the cooling system remain the primary considerations. Hawk specifies that Classic Cool 180° is not suitable for thermosiphon cooling systems.

Important: Properly prepare the system with Prep Fluid

Preparing the system is essential before switching to Hawk waterless cooling fluid if the engine contains or has contained water-based cooling fluid. In a classic car, simply draining the system may leave residual water in the engine block, radiator, heater, or various pipes.

The conversion must therefore be properly carried out beforehand using the Prep Fluid 5L preparation fluid. This helps remove any residual water remaining after the drain before the final fill with Hawk Classic Cool 180° waterless cooling fluid.

After conversion, Hawk recommends that the residual water content be ideally 3% or less. This value can be checked using a refractometer. Careful preparation is essential to fully enjoy the benefits of a water-free cooling system.

The Benefits of Hawk Classic Cool 180° Cooling Fluid

• Specially formulated forclassic cars: designed for classic engines, primarily cast iron, with steel, copper, and aluminum components.
• 100% water-free: Can be used undiluted with water after proper preparation of the water circuit.
• Boiling point above 180°C: significantly limits boiling and vapor formation in the hottest areas of the engine.
• Freezing point below -40°C: no additional antifreeze is required.
• Low vapor pressure: reduces stress on hoses, gaskets, and various cooling system components.
• Reduced cavitation erosion: helps preserve the components of the cooling system.
• Corrosion protection: The absence of water helps eliminate oxidation corrosion, according to Hawk—a particularly valuable benefit for older engines and cooling systems.
• Heat protection: Reduced vapor formation and hot spots help limit certain overheating conditions that can lead to cylinder head gasket failure.
• Less stress on the water pump: low vapor pressure and reduced cavitation help preserve the water pump and cooling system.
• Extremely long operating time: Hawk waterless coolant is designed for extremely long-term use when used properly and not contaminated with water.

Features of Hawk Classic Cool 180° 5L Waterless Cooling Fluid

• Type: Waterless engine cooling fluid
• Brand: Hawk Waterless Coolants
• Range: Classic Cool 180°
• Capacity: 5 liters
• Application: Classic cars / vintage cars
• Recommended for: Vehicles from approximately 1950 to 1980
• Engine type: Classic engines, primarily cast iron
• Materials: Cast iron / steel / copper / aluminum
• Usage: Undiluted with water
• System preparation: Pre-treatment with Prep Fluid when converting from a water-based coolant
• Boiling point: Above 180°C
• Freezing point: Below -40°C
• Water content after conversion: Ideally ≤ 3%
• Water content check: Refractometer
• Color: Light green
• Thermosiphon compatibility: No
• Former brand name: Evans Waterless Coolants
• Former product name: Evans Classic Cool 180°

Why is Hawk Classic Cool 180° suitable for classic cars?

Classic cars often have engines and cooling systems that are very different from those of modern vehicles. In particular , cast iron, steel, and copper are much more prevalent, while aluminum is gradually appearing in certain components. Hawk developed Classic Cool 180° specifically for this type of construction.

As a general guideline, this formulation is particularly well-suited for classic cars produced between approximately 1950 and 1980. However, this timeframe is not a hard-and-fast rule: to select the right Hawk coolant, you must also consider the engine’s design and the materials used in its cooling system.

For older vehicles, particularly those dating from before 1950 that contain more yellow metals and certain older cast irons, Vintage Cool 180° will generally be more appropriate. For newer vehicles and high-performance engines, Hawk offers Power Cool 180°, among other options .

Why switch a classic car to waterless cooling fluid?

In a classic or collector’s car, switching to Hawk Classic Cool 180° water-free cooling fluid is particularly beneficial for preserving the cooling system. Removing water helps reduce several issues directly associated with its presence: oxidation-induced corrosion, cavitation, pressure buildup, and high-temperature vapor formation.

Corrosion is a particularly significant concern in classic vehicles, whose engines, radiators, and cooling systems may combine multiple metals and be several decades old. According to Hawk, the absence of water eliminates oxidation-induced corrosion and thus helps preserve the system’s components.

In the hottest areas of the engine, a conventional cooling fluid can also begin to vaporize. This significantly reduces heat transfer to metal surfaces and can cause localized hot spots. These phenomena can contribute to overheating and create conditions that lead to cylinder head gasket failure.

With a boiling point exceeding 180°C, Hawk Classic Cool 180° cooling fluid remains liquid at temperatures at which standard cooling fluid may begin to vaporize. This ensures the cooling fluid stays in contact with hot metal surfaces and maintains more uniform heat transfer.

Caution for vehicles equipped with thermosiphon cooling systems

Hawk Classic Cool 180° is not suitable for thermosiphon cooling systems. It is essential to verify this information before converting a classic vehicle.

A thermosiphon relies on the natural circulation of fluid created by differences in temperature and density, rather than the forced circulation found in modern cooling systems. If your vehicle uses this cooling principle, do not choose the Classic Cool 180°.

A slightly higher engine temperature may be normal

After switching to a Hawk water-free cooling fluid, the displayed operating temperature may rise slightly. Hawk indicates that an increase of approximately 3 to 7°C may be observed after conversion.

This difference does not necessarily mean the engine is overheating. The coolant remains liquid at high temperatures and helps limit vapor formation and localized hot spots in the engine.

Evans Classic Cool Becomes Hawk Classic Cool

Evans Waterless Coolants is now known as Hawk Waterless Coolants. This change concerns the brand identity and not the product formulation. The former Evans Classic Cool 180° waterless cooling fluid is now Hawk Classic Cool 180°. If you were already using Evans Classic Cool, you’ll now find this formulation under the Hawk brand.

GT2i is an official retailer of the Hawk Waterless Coolants brand. At GT2i, you’ll find Hawk waterless cooling fluids as well as the products needed to prepare and convert your cooling system.

How do you switch to Hawk Classic Cool 180° waterless cooling fluid?

When converting from a conventional cooling fluid, start by thoroughly draining the system, then prepare it with Prep Fluid. This process helps remove as much residual water as possible from the engine and cooling system after draining.

Use the 5L Prep Fluid before the final fill. After conversion, Hawk recommends that the residual water content be ideally 3% or less, which can be checked using a refractometer.

Once the cooling system has been properly prepared, Hawk Classic Cool 180° can be used undiluted with water. The volume required for filling is comparable to that used with a standard cooling fluid.

Hawk Classic Cool 180° must never be intentionally diluted with water. Adding water gradually negates the benefits sought with a waterless cooling fluid.

FAQ - Hawk Classic Cool 180° Waterless Cooling Fluid

For which cars is Hawk Classic Cool 180° recommended?
Classic Cool 180° is designed for classic and vintage cars, particularly those with engines primarily made of cast iron and featuring steel, copper, and aluminum components. As a general guideline, it is particularly suited for vehicles from approximately 1950 to 1980.

Which Hawk coolant should I choose based on my car’s age?
As a general guideline, Vintage Cool 180° is primarily suited for vehicles built up to around 1950, Classic Cool 180° for classic cars from around 1950 to 1980, while formulations for newer vehicles should be chosen based on the engine and its intended use. The year is only a guideline: the engine design and the materials used in the cooling system must always be taken into account.

Is Hawk Classic Cool 180° suitable for thermosiphon systems?
No. Hawk specifies that Classic Cool 180° is not suitable for thermosiphon cooling systems. This must be verified before converting any classic car.

Why use a water-free coolant in a classic car?
The absence of water helps prevent oxidation-induced corrosion, cavitation, and vapor formation at high temperatures. These properties are particularly beneficial for preserving older cooling systems that combine cast iron, steel, copper, and aluminum.

Should Prep Fluid be used before Hawk Classic Cool 180°?
Yes, when converting from a system that contains or has contained a water-based coolant. Simply draining the system may leave water in the engine. The system must therefore be properly prepared with Prep Fluid 5L before the final fill.

What quantity of water can remain after the conversion?
Hawk recommends that the residual water content be ideally 3% or less. This value can be checked with a refractometer.

Can Hawk Classic Cool 180° be mixed with water?
No. Hawk Classic Cool 180° must not be intentionally diluted with water, as this reduces the benefits sought with a water-free cooling fluid.

Can water be added in the event of a breakdown or emergency?
Yes, but only as a temporary fix if it is impossible to top off the water level with Hawk fluid. This solution must remain temporary. After adding water, you must drain the system again and perform a complete system flush with Prep Fluid before refilling with Hawk waterless coolant.

Do I need to add antifreeze to Hawk Classic Cool 180°?
No. The coolant already has a freezing point below -40°C. No additional antifreeze should be added.

Is it normal for the engine temperature to be slightly higher after the conversion?
Yes. Hawk indicates that an increase of approximately 3 to 7°C may be observed after switching to waterless coolant. This difference does not necessarily mean that the engine is overheating.

Are Evans Classic Cool and Hawk Classic Cool the same product?
Yes. Evans Waterless Coolants has become Hawk Waterless Coolants. The former Evans Classic Cool 180° is now marketed as Hawk Classic Cool 180°. The formulation remains unchanged.