2024 Peterbilt 389 Coolant Capacity & Type

The 2024 Peterbilt 389 typically holds between 50 to 80 quarts (approximately 47 to 76 liters) of coolant, though this can vary significantly based on the specific engine and cooling system configuration.

Quick answer

• Total Cooling System Capacity: 50 - 80 quarts (47 - 76 liters) depending on engine and cooling system.
• OEM Coolant Spec: Typically a Red/Pink, Extended Life Coolant (ELC) - often an OAT (Organic Acid Technology) formula. It's crucial to consult your engine manufacturer's specifications (e.g., Cummins, PACCAR) for the exact coolant standard required, such as ASTM D6210 or TMC RP-329.
• Mix Ratio: 50/50 prediluted or a 50/50 mix of concentrate with distilled water.

Capacity by engine option

The Peterbilt 389 can be equipped with various engines, each having different cooling system capacities. Always refer to your specific engine's owner's manual for the precise capacity.

Flush interval

For heavy-duty trucks like the Peterbilt 389, coolant flush intervals are generally much longer than passenger vehicles due to the use of ELCs:

• Normal Duty: 600,000 miles, 6 years, or 12,000 hours, whichever comes first.
• Severe Duty (e.g., extreme conditions, heavy hauling, frequent idling): Intervals may be slightly reduced, but quality ELCs still offer significant longevity. It's more critical to monitor coolant condition frequently in severe service.

Always check your engine manufacturer's specific recommendations for drain and fill intervals, as well as supplemental coolant additive (SCA) or extender requirements if applicable to your coolant type.

How to refill & bleed

Refilling and bleeding the cooling system on a heavy-duty truck like the Peterbilt 389 requires careful attention due to the large volume and complexity of the system.

1. Drain Old Coolant: With the engine cool, open the drain cock(s) on the bottom of the radiator and any engine block drains. Collect all old coolant in appropriate containers.
2. Flush (Optional but Recommended): If changing coolant types or if the old coolant was contaminated, flush the system with distilled water until it runs clear. Specialized cooling system flush products can be used according to their directions.
3. Close Drains & Refill: Close all drain cocks. Slowly fill the system with the specified 50/50 prediluted ELC, or a concentrate mixed with distilled water, through the surge tank/fill neck. Filling slowly helps prevent air pockets.
4. Start Engine & Circulate: Leave the surge tank cap off (or loose). Start the engine and run it at a fast idle (around 1200-1500 RPM) with the heater on