FASS FAQ: What's up with the new Heat Sink?

Jake H • June 19, 2026

Thinking about buying a FASS Diesel Fuel System? This blog is for you!

We recently updated our Titanium Signature Series PLUS and Industrial Series PLUS with a custom-built Heat Sink—so we thought it was good timing for an updated FAQ article. Let's get rolling!

1. What does the Heat Sink do?

Included on all Titanium Signature Series PLUS and Industrial Series PLUS Fuel Systems, the heat sink lowers the motor temperature of the FASS by up to 20°. Make no mistake, FASS Fuel Systems are already built to outlast your truck—the addition of the Heat Sink is simply another step in our pursuit of building the perfect diesel fuel system.

2. Why didn't the FASS Fuel System I already bought come with the Heat Sink?

Our mission at FASS Diesel Fuel Systems is to build the most reliable, highest return on investment (ROI) products possible. Naturally, this means that new upgrades and features are added to existing product lines!

3. Can I install the Heat Sink on the FASS Fuel System I already bought?

Yes! The Heat Sink is available for purchase separately if you'd like to add it to an existing FASS Fuel System! Please make sure you select the right Heat Sink Size

4. Do I NEED the new Heat Sink?

Nope! FASS Diesel Fuel Systems are built to outlast your truck, and are backed by an industry-leading warranty (once registered). While the Heat Sink is an awesome addition, it is not a mandatory component.

5. What's the difference between the Drop-In, Titanium Signature Series, Titanium Signature Series PLUS, Titanium Signature Series No-Drop, Titanium Signature Series No-Drop PLUS, and Industrial Series PLUS Fuel Systems?

This can be a bit confusing—allow us to explain:

Drop-In Series Fuel Systems are a bolt-in filtration unit that provide MAXIMUM fuel quality, while utilizing your factory fuel pump for fuel flow. Drop-In Fuel Systems improve fuel quality, NOT how much is delivered to your engine.
Titanium Signature Series Fuel Systems improve both fuel filtration AND fuel flow. With these kits, your factory fuel pump is NOT used anymore. These Systems require a more technical installation than a Drop-In Fuel System, but include everything you need to improve fuel filtration and flow.
Titanium Signature Series PLUS Fuel Systems add black O-Ring Boss (ORB) fittings to the Titanium Signature Series Fuel System, as well as the Heat Sink mentioned above.

Titanium Signature Series No-Drop Fuel Systems add our popular Fuel Sump Kit to the standard Titanium Signature Series Fuel System. By including our Fuel Sump Kit, you no longer need to lower your truck's fuel tank for installation—hence the name "No-Drop".
Titanium Signature Series No-Drop PLUS Fuel Systems include ALL the extras—black ORB fittings, Heat Sink, and our Fuel Sump Kit. The No-Drop PLUS Fuel System is the ultimate version of a FASS Diesel Fuel System for your Cummins, Duramax, or Powerstroke.
Industrial Series PLUS Fuel Systems are specifically designed for commercial trucks, farm/construction equipment, diesel generators, and other diesel-powered equipment. These systems do not require a dedicated fuel return line, which drastically simplifies and shortens the installation process.

If you have questions about which FASS Diesel Fuel System is right for your truck or diesel equipment, please contact us today. As always, our mission here at FASS is maximum return on your investment!

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