Mishimoto Expansion Tank

2019–2025 Ram 2500 / 3500 6.7L Diesel

Part #: MMRT-RAM-19BK

Overview

The Mishimoto Expansion Tank is a premium replacement for the factory plastic coolant reservoir found on 2019 to 2025 Ram 2500 and 3500 trucks equipped with the 6.7L Cummins diesel engine. Designed to address the common issues of cracking, discoloration, and internal degradation associated with the stock plastic tank, this aluminum expansion tank offers enhanced durability and reliability. It is an ideal upgrade for Ram owners seeking to improve their cooling system’s longevity and maintain optimal engine temperatures under demanding conditions.

Built to withstand the rigors of heavy-duty use and extreme heat cycles, the Mishimoto tank ensures consistent coolant flow and prevents air pockets that can compromise engine cooling. Beyond its functional benefits, it also adds a clean, professional appearance to the engine bay, making it a smart choice for both performance enthusiasts and daily drivers.

Key Features

This expansion tank combines robust construction with thoughtful engineering to deliver superior performance and ease of use:

• Constructed from high-quality aluminum for superior strength and heat resistance
• TIG-welded seams provide leak-proof durability under high pressure and temperature
• Internal baffles prevent coolant starvation and reduce air pocket formation
• Direct bolt-on replacement for the factory tank with no modifications required
• Includes OEM-style coolant level sensor for full compatibility with factory warning systems
• Installation does not require draining the entire cooling system
• Available in micro-wrinkle black finish for a sleek, factory-inspired look
• Can be customized further with powder coating, anodizing, or hydro-dipping
• Backed by Mishimoto’s Lifetime Warranty for peace of mind

Construction & Design

The Mishimoto Expansion Tank is expertly crafted from durable aluminum, chosen for its excellent thermal conductivity and resistance to cracking or warping under heat stress. The tank’s TIG-welded construction ensures a strong, leak-free assembly capable of withstanding the harsh conditions typical of diesel engine cooling systems. Internal baffles are strategically placed to maintain consistent coolant circulation and eliminate air pockets that can lead to overheating or inefficient cooling.

Its design replicates the mounting points and sensor provisions of the factory tank, allowing for a seamless swap without the need for additional adapters or modifications. The micro-wrinkle black finish not only enhances corrosion resistance but also provides a refined appearance that complements the engine bay’s aesthetics.

Installation & Fitment

Installation is straightforward and user-friendly, requiring no specialty tools or extensive mechanical experience. The Mishimoto Expansion Tank installs directly in place of the OEM plastic reservoir on 2019–2025 Ram 2500 and 3500 trucks with the 6.7L Cummins diesel engine. Because the design allows for sensor integration and mounting compatibility, there is no need to drain the entire cooling system, minimizing downtime and mess.

All necessary provisions for factory coolant level sensors are included, ensuring that the truck’s original low coolant warning system functions exactly as intended after installation.

What’s Included

• Mishimoto aluminum expansion tank (micro-wrinkle black finish)
• OEM-style coolant level sensor
• All necessary mounting hardware and fittings
• Installation instructions

Ideal For

This expansion tank is perfect for Ram 2500 and 3500 owners who want to upgrade their cooling system’s reliability and appearance. It is especially beneficial for those who frequently tow, haul heavy loads, or operate their trucks in demanding environments where the factory plastic tank may fail prematurely. Performance enthusiasts and diesel truck owners looking for a durable, long-lasting cooling solution will appreciate the Mishimoto Expansion Tank’s combination of strength, functionality, and style.

Mishimoto is a performance cooling brand offering aluminum radiators, intercoolers, oil coolers, hoses, and supporting hardware built to manage heat on hard-driven street and track vehicles. For boosted setups and towing/off-road rigs alike, Mishimoto upgrades are designed to increase cooling capacity and reliability where factory systems can become a limitation.