Diesel tank maintenance is essential to keeping your fleet running smoothly, especially as temperatures begin to drop in the fall. Even small issues with fuel handling or storage can lead to major setbacks such as downtime, frozen fuel, or costly repairs. Whether you operate heavy-duty trucks, construction equipment, or resell diesel, maintaining clean, dry tanks is the key to protecting your engines and your bottom line.
Follow these diesel tank maintenance best practices to help keep your tanks and systems performing reliably all year long.
Use Diesel Designed to Clean and Protect Your Fuel System
Why it matters:
Premium diesel fuel does more than power your fleet, it helps protect it. Standard diesel can lead to injector buildup, corrosion, and gelling in cold weather, all of which increase maintenance time and costs. Using a pre-treated premium diesel like Sprague’s RoadForce helps to keep your fuel system cleaner, helps stabilize fuel quality, and helps prevent the cold-weather issues that appear as temperatures drop. RoadForce’s advanced additive package includes detergents, stabilizers, and cold flow improvers that help maintain tank and engine health year-round.
What to do:
- Choose a cold flow improver pre-treated premium diesel such as RoadForce, formulated for dependable winter performance.
- Ask your supplier about premium additive packages that enhance fuel stability, lubricity, and corrosion protection.
- Use premium diesel consistently to reduce buildup, minimize downtime, and extend system life.
Check for and Remove Water from Tanks
Why it matters:
Water in diesel can lead to a range of serious issues if not managed properly. It accelerates corrosion in tanks, lines, and fittings, which can weaken your fuel system over time. When moisture is present, it also creates an environment where microbial growth, often referred to as “fuel bugs,” can thrive, clogging filters and damaging injectors. In colder weather, those same water droplets can freeze, forming ice crystals that restrict fuel flow and cause filter plugging during the season’s first cold snap.
Condensation and loose fittings are the most common culprits, and unmanaged water can shorten both tank and engine life.
What to do:
- Drain water separators and tank low points regularly.
- Use an automatic tank gauging system or water-detecting paste on a gauging stick to check for moisture.
- Schedule a complete tank cleaning by a qualified professional at least once a year or if water contamination is found.
- Removing water before the first freeze is one of the most important steps you can take to keep your fleet running smoothly.
Inspect Fill and Vapor Caps for Tight Seals
Why it matters:
Cracked or missing gaskets let rain, dust, and debris into the fuel system, which can quickly lead to contamination or water intrusion. A tight seal keeps the system clean and dry and is an important part of ongoing diesel tank maintenance.
What to do:
- Inspect fill boxes, caps, and vapor vents regularly.
- Replace damaged or missing gaskets immediately.
- Make sure all fittings are water- and vapor-tight, especially before winter.
Keep Tanks Topped Off
Why it matters:
When tanks sit partially full, humid air condenses on the tank walls as temperatures change, especially overnight or during fall and spring. Keeping tanks full minimizes airspace and reduces condensation risk.
What to do:
- Fuel trucks at the end of the day rather than the start.
- Top off bulk tanks whenever possible, particularly before long storage periods or cold snaps.
Replace Fuel and Air Filters Regularly
Why it matters:
Filters capture the dirt, microbes, and moisture that can damage injectors or restrict fuel flow. A clogged filter can be the first sign of microbial growth or fuel degradation, making filter replacement a key part of your diesel tank maintenance plan.
What to do:
- Follow your manufacturer’s filter-change intervals or shorten them if contamination is detected.
- Keep spare filters and parts on hand during the winter months.
- Log replacements as part of your preventive maintenance schedule.
Drain Saddle Tanks and Water Separators Frequently
Why it matters:
Fleet tanks, especially saddle tanks, are exposed to vibration, temperature swings, and road spray, all of which can introduce condensation or moisture. Regular draining prevents water accumulation that can cause freezing or microbial growth.
What to do:
- Drain saddle tanks and water separators at least weekly, more often during temperature swings.
- Check for signs of rust or corrosion near drain valves.
- Keep detailed logs to track water removal frequency.
Establish a Preventive Maintenance (PM) Program
Why it matters:
A structured PM plan is the foundation of effective diesel tank maintenance. It helps reduce downtime, control costs, and extend the life of your fleet and fuel systems.
What to do:
- Create a consistent inspection schedule that includes fuel, air, and water checks.
- Record fuel deliveries, filter changes, and water removals in a central log.
- Partner with your supplier to analyze fuel samples and identify early signs of contamination.
- A well-managed PM program can add measurable savings to your bottom line while keeping your operation running at peak efficiency.
Maintain Bulk Storage Tanks as a Secondary Line of Defense
Why it matters:
Even if your fleet uses delivered or mobile fueling, clean storage tanks are critical to maintaining overall fuel integrity. Contamination at the source can affect every vehicle you fill.
What to do:
- Inspect and clean bulk tanks periodically.
- Monitor tank bottoms with gauging paste or automatic sensors.
- Work with your supplier to schedule routine testing and tank cleanings.
Partner with a Reliable Supplier
Why it matters:
Maintenance is only half the equation. Clean, premium fuel from a trusted supplier ensures your preventive work pays off.
What to do:
- Source from a supplier that manages its own distribution network and testing protocols.
- Ask about premium blends like RoadForce, which includes detergents and cold flow protection in every gallon.
- The right partnership helps prevent problems before they start, keeping your fleet on the road when it matters most.
By checking, sealing, and cleaning your tanks regularly, and by using premium, pre-treated diesel, you’ll keep your operation running efficiently all year long.
To make this process easier, we’ve created a quick guide with the best tank maintenance tips: view diesel tank maintenance best practices cheat sheet.
Clean tanks and premium fuel go hand in hand. Connect with Sprague to explore our premium diesel options and gain expert insights on refined products and maintenance best practices that keep your operation running smoothly all year long.
