2018 Freightliner Cascadia Coolant Capacity & Type

The 2018 Freightliner Cascadia typically holds between 60 to 75 quarts (56.8 to 71.0 liters) of coolant, depending on the specific engine and cooling system configuration.

Quick Answer

• Total Cooling System Capacity: 60-75 quarts (56.8-71.0 liters)
• OEM Coolant Spec: Typically an OAT (Organic Acid Technology) or NOAT (Nitrited Organic Acid Technology) coolant, dyed pink or red. Look for Detroit Diesel DFS900AA specification.
• Mix Ratio: 50/50 prediluted, or 50% concentrate and 50% distilled water.

Capacity by Engine Option

The coolant capacity for your 2018 Freightliner Cascadia will primarily depend on the engine installed. Heavy-duty trucks often have variations in radiator size and cooling system components based on engine horsepower and application.

Note: These are approximate values. Always consult your owner's manual or the engine manufacturer's specifications for the precise capacity of your vehicle.

Flush Interval

Maintaining your coolant is crucial for the longevity of your engine. The flush interval can vary based on the type of coolant used and operating conditions.

• Normal Duty: For most OAT/NOAT coolants meeting the Detroit Diesel DFS900AA specification, a typical flush interval is around 600,000 miles, 12,000 hours, or 6 years, whichever comes first.
• Severe Duty (e.g., heavy hauling, frequent idling, extreme temperatures): It is recommended to reduce the flush interval by approximately 25-30% for vehicles operating under severe conditions. This could mean flushing as early as 450,000 miles or 9,000 hours.

Regularly check your coolant's condition using test strips to monitor its additive levels and pH, regardless of mileage or time.

How to Refill & Bleed

Properly refilling and bleeding the cooling system in a 2018 Freightliner Cascadia is essential to prevent air pockets, which can lead to overheating. Due to the size and complexity of commercial vehicle cooling systems, a vacuum fill tool is highly recommended.

1. Safety First: Ensure the engine is completely cool before starting. Wear appropriate personal protective equipment (PPE).
2. Drain System: Open the radiator drain cock and any other drain points (e.g., on the engine block) to completely drain the old coolant. Flush with distilled water until the water runs clear if performing a full flush.
3. Close Drains & Fill: Close all drain points. If using a vacuum fill tool, connect it according to the manufacturer's instructions and draw a vacuum on the system. This will draw in the new coolant without introducing air.
4. No Vacuum Fill Tool (Manual Method): Slowly add the correct 50/50 coolant mixture to the surge tank. Fill until the coolant level stabilizes.
5. Bleeding (Manual Method):
   • Start the engine with the heater set to maximum heat (fan speed low) and the surge tank cap off.
   • Allow the engine to reach operating temperature. As the thermostat opens, the coolant level in the surge tank may drop. Add more coolant as needed to maintain the proper level.
   • Look for any bleed screws or valves on the thermostat housing or other high points of the cooling system. Gently open them to release trapped air until a steady stream of coolant emerges, then close them.
   • Monitor the temperature gauge closely. Squeeze radiator hoses to help dislodge air bubbles.
   • Once the engine is at operating temperature and no more air bubbles appear in the surge tank, install the cap.
6. Test Drive & Recheck: Take the truck for a short test drive, observing the temperature gauge. After the engine cools, recheck the coolant level in the surge tank and top off if necessary.

Common Cooling System Issues for this Generation

Owners of 2018 Freightliner Cascadia trucks may encounter certain cooling system issues, some of which are common to heavy-duty vehicles:

• Coolant Leaks: Due to the extensive network of hoses, clamps, and radiators, leaks can occur. Common culprits include radiator end tank seams, heater hoses, and water pump seals.
• EGR Cooler Issues: The Exhaust Gas Recirculation (EGR) cooler is a critical component for emission control. Failures in the EGR cooler can lead to internal coolant leaks, consumption, and overheating. Symptoms may include white smoke from the exhaust, coolant loss without visible external leaks, or engine performance issues.
• Thermostat Malfunctions: A stuck-open thermostat can lead to the engine running too cool, reducing fuel efficiency. A stuck-closed thermostat can cause severe overheating and engine damage.
• Radiator Clogging: Over time, debris, scale, or incompatible coolant types can lead to radiator fin damage or internal clogging, reducing cooling efficiency.
• Belt Tensioner and Pulley Problems: While not directly coolant system components, belts drive the water pump. Issues with the serpentine belt, tensioner, or idler pulleys can lead to reduced water pump efficiency and overheating.

Regular inspections and adherence to maintenance schedules are paramount for preventing these issues.

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