2018-2021 Peterbilt 579 / Kenworth T680 / Kenworth T880 Coolant Reservoir Tank OEM # 603-5570, 6035570, DR10400, DR104004 

FOR PIPE DESIGN (ONE BIG; ONE SMALL PORT)

OEM Part Number: 

• 603-5570
• 6035570
• DR10400
• DR104004

✅ Product Overview:

This high-quality coolant reservoir tank is a direct-fit replacement for 2018 to 2021 Peterbilt 579, Kenworth T680, and Kenworth T880 models. Designed for durability and precision, it includes a coolant cap and sensor—providing a complete, ready-to-install solution.

Manufactured from heavy-duty, leak-resistant plastic, this tank is built to withstand the demanding conditions of commercial trucking. Each unit is rigorously tested at 20 PSI for leak prevention, meets IATF 16949 automotive quality standards, and is validated through our Thousand Truck Fitting Test (TTFT) to ensure real-world reliability and perfect fitment.

🚚 Vehicle Compatibility:

Peterbilt 579 – 2018, 2019, 2020, 2021

Kenworth T680 – 2018, 2019, 2020, 2021

Kenworth T880 – 2018, 2019, 2020, 2021

🔍 Fitment based on OEM specifications. Please confirm part number or contact us with your VIN to verify compatibility.

📦 What’s Included:

✅ Coolant Reservoir Tank

✅ Coolant Level Sensor

✅ Coolant Tank Cap

🛠 Key Features:

✅ Direct replacement for OEM specifications

✅ Made from heavy-duty plastic to resist heat and prevent leaks

✅ Includes sensor and cap pre-installed

✅ Passes 20 PSI leak test on 100% of units

✅ Certified to IATF 16949 automotive quality standards

✅ Verified fit through Thousand Truck Fitting Test (TTFT) 

⚠️ Important Fitment Warning:

Please verify your existing coolant tank configuration before purchase.
Ensure hose connections, sensor type, and mounting points match your original unit to guarantee proper fitment.

💬 Questions?

Need to confirm fitment? Message us with your OEM number or VIN — our team is happy to assist!