Hawk Prep Fluid 25L Cooling System Preparation Fluid

Hawk Prep Fluid 25L is designed to prepare cooling systems prior to their conversion to Hawk Waterless Coolants. It plays an essential role: after draining a conventional cooling fluid, it helps remove any water trapped in the engine and the cooling system.

A standard drain is not always sufficient to remove all the water. A residual quantity may remain in the engine block, cylinder head, radiator, heater core, and various lines. Thanks to its hygroscopic properties, Hawk Prep Fluid absorbs this residual water before the system is finally filled with the appropriate waterless coolant.

The 25-liter container is particularly well-suited for garages, tuners, restoration shops, racing teams, and professionals who regularly convert to Hawk waterless cooling fluids. It is also suitable for preparing multiple vehicles or circuits requiring a large volume.

Important: Hawk Prep Fluid is a preparation fluid and not a cooling fluid intended to remain in the engine. After it has fulfilled its purpose and absorbed the residual water, it must be drained before adding the final Hawk waterless cooling fluid.

The Benefits of Hawk Prep Fluid

• Conversion to a waterless coolant: specially developed to prepare the system before using Hawk Waterless Coolants.
• Removal of residual water: Its hygroscopic properties allow it to remove any water remaining in the engine after draining.
• Complete system preparation: circulates through the engine, radiator, and various lines to remove residual moisture.
• Helps flush out impurities: helps carry away loose dirt and deposits present in the system.
• Water-free formulation: allows the engine to be flushed without reintroducing water into the system.
• Compatible with various engines: allows the system to be flushed before using the Hawk formulation appropriate for the vehicle.
• Optimized conversion: helps achieve a residual water content ideally at or below 3%.
• 25-liter professional size: suitable for workshops, restorers, tuners, and users performing multiple conversions.

Why is Prep Fluid essential before using a water-free coolant?

When a system has been running on a standard water-based cooling fluid, simply opening the drain plug usually does not allow the system to be completely drained.

Volumes of fluid may remain trapped in certain parts of the engine block or cylinder head. Filling the engine immediately with Hawk coolant would then cause the product to mix with this residual water.

However, the benefits of Hawk technology rely precisely on the system operating without water. Proper preparation therefore allows you to fully benefit from the reduced vapor formation, oxidation corrosion, cavitation, and vapor pressure provided by the selected Hawk coolant.

Specifications of Hawk Prep Fluid 25L

• Brand: Hawk Waterless Coolants
• Product: Prep Fluid
• Type: Cooling system preparation fluid
• Volume: 25 liters
• Function: Preparation prior to conversion to a waterless cooling fluid
• Compatibility: All engine types compatible with a Hawk conversion
• Main function: Absorption of residual water
• Property: Hygroscopic
• Additional function: Helps remove loose dirt and deposits
• Formulation: Water-free
• State: Low-viscosity synthetic liquid
• Residual water after conversion: Ideally 3% or less
• Residual Water Control: Refractometer
• End use: Must be drained before final filling with the appropriate Hawk fluid
• Packaging: 25 liters
• Applications: Workshops / tuners / restoration / racing / classic cars
• Former brand: Evans Waterless Coolants
• Former product name: Evans Prep Fluid

How do you properly prepare a cooling system with Hawk Prep Fluid?

The first step is to drain the old cooling fluid as completely as possible. The goal is to allow the maximum possible quantity of the cooling fluid to drain out naturally before adding the Prep Fluid.

Hawk Prep Fluid is then used in the cooling system to remove any water that could not be drained during this initial step. Thanks to its hygroscopic properties, it absorbs residual water present in various parts of the system.

Once the preparation is complete, the Prep Fluid must be drained. It must not be left in the system as the final cooling fluid.

The system can then be filled with the Hawk coolant formulation appropriate for the vehicle. After the conversion, Hawk recommends that the residual water content be ideally 3% or less. This value can be checked using a refractometer.

Which Hawk cooling fluid should be used after Prep Fluid?

Prep Fluid prepares the cooling system, but the choice of the final coolant depends on the vehicle, the engine design, the materials used, and its intended use. Hawk offers several formulations tailored to different applications.

• Hawk Power Cool 180°: for sports cars, tuned vehicles, race cars, and high-performance engines.
• Hawk Classic Cool 180°: for classic and collector’s cars. The period from approximately 1950 to 1980 serves as a guideline for selection, but engine design and cooling system materials remain the primary considerations.
• Hawk Vintage Cool 180°: for vintage and historic vehicles, with a focus on vehicles up to the years 1950 and 1951 and engines featuring components made primarily of cast iron, copper, and brass.
• Hawk PowerSports R: for street bikes, sport bikes, and racing bikes.

These time periods provide a quick guide for choosing between Vintage Cool and Classic Cool, but the vehicle’s year of manufacture should not be used as the sole criterion. The engine technology and the composition of the cooling system must also be verified.

A 25-liter container for professionals

Hawk Prep Fluid 25L is particularly suitable for workshops that regularly convert vehicles to waterless coolants. Rather than using multiple small containers, this size provides a volume sufficient for preparing several vehicles.

It is particularly well-suited for automotive tuners, motorsports specialists, garages working on classic cars, restorers of historic vehicles, and motorcycle shops.

The quantity of Prep Fluid required for each conversion depends on the capacity and design of the fluid system being prepared.

Evans Prep Fluid Becomes Hawk Prep Fluid

Evans Waterless Coolants is now known as Hawk Waterless Coolants. The product historically known as Evans Prep Fluid is now marketed under the name Hawk Prep Fluid.

This change affects the brand identity, not the product: the formulation remains unchanged. Users already familiar with the Evans system will therefore find the prep fluid under the new Hawk brand.

GT2i is an official reseller of Hawk Waterless Coolants and offers the products needed to prepare and convert cooling systems to waterless technology.

FAQ - Hawk Prep Fluid 25L

What is Hawk Prep Fluid used for?
Prep Fluid is used to prepare a cooling system before switching to a Hawk waterless cooling fluid. Its hygroscopic properties help remove residual water remaining in the engine after a flush.

Why is it necessary to use Prep Fluid if the system has already been drained?
Because draining the system does not necessarily remove all the water. Fluid may remain in the engine block, cylinder head, radiator, heater core, or certain lines. Prep Fluid helps remove this residual water.

Is Prep Fluid a cooling fluid?
It is a preparation fluid. It should not remain in the engine permanently and must be drained before filling with the appropriate Hawk water-free cooling fluid.

Why choose the 25-liter container?
The 25L size is primarily intended for workshops, professionals, tuners, and restorers performing multiple conversions or working on systems that require large volumes.

What quantity of Prep Fluid should be used?
The quantity depends on the capacity and design of the cooling system. The Prep Fluid must be able to circulate properly through the system to remove any residual water.

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 using a refractometer.

Does Hawk Prep Fluid act as a cleaner for the system?
Its primary function is to remove residual water. It also helps flush out loose dirt and deposits, but it does not replace a specific cleaning or decoking treatment when a circuit is heavily contaminated.

Which Hawk fluid should be used after preparation?
The choice depends on the application: Power Cool 180° for sports cars and high-performance engines, Classic Cool 180° for classic cars, Vintage Cool 180° for older vehicles, and PowerSports R for street, sport, and racing motorcycles.

Can the drained Prep Fluid be reused?
The Prep Fluid absorbs residual water as it flows through the system. Once used and saturated with water, it should not be considered a new product for performing another conversion.

Are Evans Prep Fluid and Hawk Prep Fluid different?
No. Evans Waterless Coolants has become Hawk Waterless Coolants. Evans Prep Fluid is now marketed under the name Hawk Prep Fluid, and its formulation remains unchanged.