Fuel Cap Cover for Knapheide Work Trucks
$15,000+ Knapheide Body • Full Diesel Tank • Zero Fuel Cap Protection
You invested in a Knapheide service body because you demand the best. But the fuel cap on the Ford or Ram chassis underneath? Completely exposed. The Work Truck Fuel Vault is the armored fuel cap cover that completes the Knapheide security package.
Founders Edition pricing — starting at $99.95 (Save up to $50)
Knapheide Locks Everything — Except the Fuel Cap
Every Knapheide compartment has a lock. Every tool drawer, every side panel, every door. But the fuel cap sits on the chassis — outside Knapheide's scope — completely naked.
- Knapheide service bodies lock every compartment — but the fuel cap has no cover
- Ford and Ram chassis ship with zero fuel filler protection from the factory
- Knapheide trucks carry 40–68 gallons of diesel — worth $200–$350 per tank
- Thieves target Knapheide trucks because they know they carry full tanks and valuable tools
- Fuel theft costs $500–$1,000 per event in fuel, downtime, and emergency refueling
- Locking gas caps are defeated in seconds — not worthy of a Knapheide-quality truck
The Fuel Cap Cover Your Knapheide Deserves
The Work Truck Fuel Vault is the armored locking fuel cap cover built for the same quality standard as your Knapheide body. Full coverage, real lock, bolt-on install.
- Armored cover over the entire fuel filler area — cap, neck, and access point
- Tumbler lock + security torx fasteners — Knapheide-quality hardware
- UV-stable composite — built to match the durability of your Knapheide body
- Zero interference with Knapheide compartments, doors, or body panels
- Bolt-on in 8–15 minutes — no drilling, cutting, or modifications
- Made in the USA — Sarasota, Florida
The Part The Factory Forgot
The Work Truck Fuel Vault is an armored, locking fuel door that covers the entire fuel access area on your work truck. No more exposed caps. No more easy targets.
Why Didn't This Exist Before?
Despite billions lost to fuel theft every year, nobody built a real solution for commercial work trucks. Here's why.
"Good Enough" Thinking
The industry defaulted to cheap aftermarket locking gas caps. A $15 key-locked cap was considered good enough — until thieves proved otherwise with a pair of pliers.
Upfitters Focus on the Body, Not the Cap
Manufacturers like Knapheide and Reading engineer every compartment lock on the service body — but the chassis fuel pocket belongs to Ford or Ram. Nobody owned the gap.
The Zero-Drill Engineering Problem
Consumer billet doors are made for flat pickup beds. The recessed fuel pocket on a commercial chassis is a completely different geometry — and drilling risks voiding the chassis warranty.
The Cost Was Just "Absorbed"
Fleets treated fuel theft like weather damage. A $500 siphoning hit got buried in operating expenses. Without a purpose-built product available, the problem was simply accepted.
The Work Truck Fuel Vault is the industry's first drop-in armored fuel door that uses existing factory mounting points. No drilling. No cutting. No warranty risk.
Knapheide Owners Who Covered Their Fuel
Contractors
Your Knapheide service truck sits at the jobsite overnight. Cover the fuel cap like you cover your tools.
Fleet Managers
Cover every fuel cap across your Knapheide fleet. One part, every truck.
Municipal Fleets
City and county Knapheide trucks park in open yards. Cover the fuel.
Utility Companies
Knapheide utility trucks in remote areas need covered fuel caps.
Knapheide Dealers
Include a fuel cap cover in every Knapheide upfit. Your customers will love it.
Landscapers
Knapheide bodies on dump trucks and spray trucks — cover the fuel cap.
Chassis Compatibility
Purpose-built for the most popular commercial chassis platforms in the industry.
Ford
Super Duty & Commercial Chassis
- F-350 Chassis Cab
- F-450 Chassis Cab
- F-550 Chassis Cab
- F-600 Chassis Cab
- E-350 / E-450
- F53 Workhorse
Ram
Chassis Cab Heavy Duty
- Ram 3500 Chassis Cab
- Ram 4500 Chassis Cab
- Ram 5500 Chassis Cab
Our Guarantee
Limited Lifetime Warranty
Built to last. Warranted against defects in material and workmanship for the life of the vehicle on which it was originally installed.
30-Day Money Back
Not satisfied? Return within 30 days of receipt for a full refund. No questions asked.
Free Replacements
If your Fuel Vault is defective under normal use within the warranty period, we replace it at no charge.
Frequently Asked Questions
Does the Fuel Vault fit trucks with Knapheide service bodies?
Yes. The Fuel Vault mounts to the Ford or Ram chassis at the fuel filler area — not the Knapheide body. It fits any Ford F-350 through F-600, E-Series, or Ram 3500–5500 chassis with any Knapheide body.
Will it interfere with Knapheide compartment doors?
No. The Fuel Vault mounts near the cab at the fuel filler neck. It does not touch, overlap, or interfere with any Knapheide body compartments or doors.
What Knapheide models does it work with?
All of them — KnapService, KUVcc, Utility, Forestry, Crane, Mechanics, Platform, and Stake bodies. The Fuel Vault mounts to the truck chassis, not the body.
Why doesn't Knapheide include a fuel cap cover?
Knapheide builds the service body. The fuel cap is on the truck chassis, which comes from Ford or Ram. Neither Ford nor Ram includes any fuel cap protection — that's the gap the Fuel Vault fills.
How does it install?
Bolt-on in 8–15 minutes with basic hand tools. No drilling, cutting, or body modifications.
How much does it cost?
Founders Edition starts at $99.95 with free shipping.
Is there a warranty?
Yes — Limited Lifetime Warranty and a 30-day money-back guarantee.
Cover the Fuel Cap on Your Knapheide — Starting at $99.95
Armored locking fuel cap cover for Knapheide service body trucks. Bolt-on. No drilling. Lifetime warranty.
Secure checkout • Free US shipping • No charge until your order ships