2018 Volvo VNR — Coolant Capacity & Type

The 2018 Volvo VNR holds approximately 56 to 68 quarts (53 to 64 liters) of coolant, depending on the engine and specific configuration.

Quick Answer

• Total Cooling System Capacity: 56-68 quarts (53-64 liters)
• OEM Coolant Spec: Volvo Coolant VCS (Yellow, OAT - Organic Acid Technology) or compatible extended-life nitrite-free OAT coolant meeting Volvo VCS standards.
• Mix Ratio: 50/50 Pre-mix or 50/50 concentrate with distilled water.

Capacity by Engine Option

Note: These figures are approximations and may vary slightly based on specific truck configuration, such as auxiliary heaters or additional cooling systems. Always consult your owner's manual for the most accurate information.

Flush Interval

Maintaining your coolant is crucial for the longevity of your 2018 Volvo VNR's engine. Adhering to the manufacturer's recommended flush intervals will prevent cooling system issues.

• Normal Duty: Replace coolant every 600,000 miles, 12,000 operating hours, or 6 years, whichever comes first.
• Severe Duty: In harsh operating conditions, it is advisable to inspect your coolant more frequently and consider reducing the flush interval.

Always use a high-quality OAT coolant that meets Volvo VCS specifications and ensure proper mixing with distilled water.

How to Refill & Bleed

Refilling and bleeding the cooling system on a Volvo VNR requires careful attention to ensure all air is expelled, preventing hot spots and potential engine damage. It is often recommended to have this procedure performed by a qualified technician.

1. Drain the System: Ensure the engine is cool. Open the petcock on the radiator and any other drain points on the engine block. Collect used coolant in an appropriate container.
2. Flush (Optional but Recommended): If performing a full flush, close drain points and refill with distilled water. Run the engine with the heater on until it reaches operating temperature, then cool and drain again. Repeat until the drained water is clear.
3. Refill with Coolant: Close all drain points. Slowly add the correct 50/50 mix of Volvo VCS coolant (or equivalent) into the coolant reservoir. Fill to the "MAX" line.
4. Bleed the System:
   • Start the engine and let it idle with the heater on maximum heat and fan speed. Keep the reservoir cap off.
   • Monitor the coolant level in the reservoir; it will likely drop as the thermostat opens and coolant circulates through the system. Top off as needed.
   • Some Volvo VNR models may have an air bleed screw located on an upper radiator hose or near the thermostat housing. Loosen this screw until a steady stream of coolant (without air bubbles) emerges, then tighten it.
   • Continue to run the engine until it reaches normal operating temperature and the cooling fans cycle on and off a few times. Gently rev the engine a few times to help dislodge air bubbles.
   • Once the engine is cool, recheck the coolant level and top off if necessary. Install the reservoir cap securely.

Common Cooling System Issues for this Generation Volvo VNR

Like any heavy-duty truck, the 2018 Volvo VNR can experience cooling system issues, especially if maintenance schedules are not followed. Some common problems include:

• Radiator Leaks: Over time, vibrations and environmental factors can cause leaks in the radiator fins or tanks. Regular inspections can identify these early.
• Water Pump Failure: The water pump is a critical component; signs of failure include leaks around the pump bearing or unusual noises.
• Thermostat Malfunctions: A faulty thermostat can lead to the engine running too hot (stuck closed) or not reaching optimal operating temperature (stuck open), impacting fuel efficiency and emissions.
• Coolant Contamination/Degradation: Using the wrong type of coolant or extending flush intervals too long can lead to coolant breakdown, corrosion, and sludge formation, clogging the system.
• Hose Leaks/Failures: Hoses can degrade, crack, or soften over time, leading to leaks. Inspect hoses regularly for any signs of wear.
• EGR Cooler Issues: The Exhaust Gas Recirculation (EGR) cooler is an integral part of the emissions system and uses engine coolant. Leaks or clogs in the EGR cooler can lead to coolant loss or engine overheating.

Regular preventative maintenance, including coolant quality checks and system inspections, is the best way to avoid costly repairs. Always use Volvo-approved parts and fluids for optimal performance and longevity.

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