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Tough Tanks - Aluminum Secondary Degas Tank R&D - Concept to Completion

Posted: February 12, 2021

Categories: Ford 6.7L Powerstroke Aluminum Secondary Degas Tank, 2011-2016, Ford 6.7L Powerstroke Aluminum Secondary Degas Tank, 2017-2019

The Ford Super Duty trucks are the definition of dependability. When it comes to utility, the mighty 6.7L Powerstroke under the hood is more than capable of towing, hauling, carrying, and just about every other activity these pickup trucks were designed to handle. While Ford intended for the Powerstroke to endure extended punishment, some of the engine bay components (specifically the secondary degas tank) might not last as long.

Ford's 6.7L Powerstroke has two cooling systems. The first is tasked with keeping the engine internals cool, as is the function of most cooling systems. The second is employed primarily to reduce the charged air temperatures within the air-to-water intercooling system. Expansion, or degas, tanks are required on both systems and allow for hot gasses to expand off the hot coolant, aiding in the cooling process. Since we already performed an overhaul on the primary system tank, we felt that the secondary system's tank deserved the same treatment.

Before we can complete a comprehensive redesign of the secondary degas tank, we need to fully understand the stock tank's layout and construction.

Pictured here is the secondary degas tank from our 2017+ F-250. Since this truck underwent some updates for the 2017 model year, you will notice some differences with the factory 2011-2016 tank, particularly the number of inlets and outlets.

To start, we extracted the tank from our 2017 F-250 for a closer look at the design. Ford opted for a two-tone outer skin, utilizing two different plastics to optimize heat resistance and keep manufacturing costs down. Additionally, the translucent upper half of the tank works as a sight glass for an easy gauge of the fluid level.

Ford wanted to further this tank's durability, so they installed metal inserts on the ports to prevent damage as the plastic degrades over time.

On the whole, the OEM tanks are sturdy and engineered for adequate durability. As previously mentioned, however, plastic degrades over time, especially when heat is involved. Since this tank mounts between the radiators and engine, and its purpose is to contain hot liquid, it's safe to say that it will be subjected to high temperatures quite often. This tank also features a seam through its center where the two materials meet, which could spring leaks over time.

Precise fitment is vital when it comes to any of our products. To make sure our production level tanks fit right out of the box, we put in plenty of legwork upfront. Using a combination of our Faro Design ScanArm, 3D modeling software, and bank of 3D printers, we're able to bring the digital model to life to confirm fitment before production.

To make sure that the secondary degas tank is up to the Super Duty name, we're ditching the plastic. Though seen above in its 3D-printed plastic form, we're opting for full aluminum construction to remove the degradation factor from the equation almost entirely.

The toughening is more than just skin deep too. For starters, functionality across the 2011-2019 range is critical, but the early models had more tied into the secondary system resulting in more inlets and outlets on the tank. Luckily for us, the tank's general shape remained the same through the years, allowing us to incorporate a set of removable ports and plugs for proper integration on all model years.

Baffling is equally essential to a degas tank. Without internal baffles, the coolant inside the tank would slosh around as the vehicle sways and allow air to enter the system, compromising cooling. Since this tank mounts to the front of the truck, it's subjected to even more bumps and sloshing. We made sure to incorporate a robust baffling system within our new design to allow for an uninterrupted coolant flow through the secondary cooling system.

Our first production sample fits like a glove and provides improved protection for our 2017+ F-250. Since we installed this tank, though, we've made even more improvements to our design, so yours will look a little different. We also made sure to offer this tank in a micro-wrinkle black powder coat finish, along with a natural option so that you can decide which style looks best under the hood.

The Ford Super Duty pickup trucks might be the poster child for long-term dependability, but coolant leaks and compromised cooling can rain on that parade. Quite literally. With improved full-aluminum construction, modular ports, and a robust internal baffling system, the Mishimoto Secondary Degas Tank is more than capable of living up to the Super Duty lifestyle. So make sure you get yours today: