Your Knapheide Locks Everything — Except the Fuel Cap
Every Compartment Locked ✓ • Every Tool Secured ✓ • Fuel Cap Wide Open ✗
You spent thousands on a Knapheide service body with locks on every compartment. But the fuel cap on your Ford or Ram chassis? Completely exposed. The Work Truck Fuel Vault is the bolt-on locking fuel door that closes the last security gap on your Knapheide-equipped work truck.
Founders Edition pricing — starting at $99.95 (Save up to $50)
The Security Gap on Every Knapheide Truck
Knapheide builds some of the best service bodies in the industry. But they mount on Ford and Ram chassis that ship with zero fuel security. That's not Knapheide's fault — it's a factory gap.
- Ford F-350 through F-600 and Ram 3500–5500 chassis have completely exposed fuel caps
- Knapheide locks protect tools and equipment — nothing protects the diesel
- Thieves know Knapheide trucks carry full diesel tanks and expensive tools
- A single siphoning event costs $500–$1,000 in fuel plus downtime
- Locking gas caps are easily defeated — pliers remove them in seconds
Complete the Build on Your Knapheide Truck
The Work Truck Fuel Vault is the missing piece your Knapheide upfit needs. Same quality, same bolt-on simplicity, same commitment to protecting what matters.
- Armored locking door covers the entire fuel filler area — cap, neck, and access point
- Works with all Knapheide service body configurations — no interference with compartments
- Bolt-on install in 8–15 minutes — no drilling, no cutting, no body modifications
- Purpose-built for Ford F-350–F-600, E-Series, F53 and Ram 3500–5500 chassis
- High-strength UV-stable composite — matches the durability of your Knapheide body
- Limited Lifetime Warranty and 30-day money-back guarantee
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.
Every Knapheide Truck Needs This
Contractors & Trades
Your Knapheide service body is full of expensive tools. Don't let thieves offset the cost by siphoning your diesel overnight.
Municipal Fleets
City and county Knapheide trucks sit in open yards. Lock the fuel the same way Knapheide locks the compartments.
Utility & Telecom
Knapheide utility bodies on Ram 4500/5500 chassis are high-value targets. The Fuel Vault locks the one thing they can't.
Knapheide Dealers
Offer the Fuel Vault as part of your Knapheide upfit package. It's the upsell that sells itself — real ROI for the customer.
Fleet Managers
Standardize fuel security across your Knapheide-equipped fleet. Volume pricing makes it easy to spec on every new truck.
Remote Operations
Knapheide trucks on pipeline, utility, and construction sites sit miles from anyone. The Fuel Vault works 24/7.
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
Locking Fuel Cap vs. Fuel Vault
See how The Work Truck Fuel Vault compares to the alternatives.
| Feature | Locking Fuel Cap | The Work Truck Fuel Vault |
|---|---|---|
| Protection Type | Cap only | Full armored door over entire fuel access |
| Tamper Resistance | Low — pliers remove in seconds | High — armored composite, torx fasteners |
| Covers Fuel Filler Area | No — cap only | Yes — full hatch coverage |
| Prevents Siphoning | Partial — hose can bypass | Yes — sealed door blocks all access |
| Prevents Contamination | No | Yes — sealed against water, dirt, debris |
| Knapheide Compatible | Generic / universal fit | Purpose-built for Ford & Ram chassis under Knapheide |
| Install Time | 1 minute screw-on | 8–15 min bolt-on (one-time, no drilling) |
| Warranty | None or 90 days | Limited Lifetime Warranty |
Feature comparison between standard locking fuel cap and The Work Truck Fuel Vault
Protection Type
Cap only
Full armored door over entire fuel access
Tamper Resistance
Low — pliers remove in seconds
High — armored composite, torx fasteners
Covers Fuel Filler Area
No — cap only
Yes — full hatch coverage
Prevents Siphoning
Partial — hose can bypass
Yes — sealed door blocks all access
Prevents Contamination
No
Yes — sealed against water, dirt, debris
Knapheide Compatible
Generic / universal fit
Purpose-built for Ford & Ram chassis under Knapheide
Install Time
1 minute screw-on
8–15 min bolt-on (one-time, no drilling)
Warranty
None or 90 days
Limited Lifetime Warranty
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 Work Truck Fuel Vault mounts to the chassis fuel filler area, not the Knapheide body itself. It fits any Ford F-350 through F-600, E-Series, F53, or Ram 3500 through 5500 chassis under a Knapheide service body.
Will installing the Fuel Vault interfere with my Knapheide compartments?
No. The Fuel Vault is designed for the fuel filler area near the cab. It does not interfere with Knapheide side compartments, doors, or tool storage. Your body layout stays exactly the same.
Why do I need this if my Knapheide body already has locks on every door?
Knapheide locks protect your tools and equipment. Nothing protects the exposed fuel cap on the truck chassis. Ford and Ram chassis cabs ship with completely exposed, unlocked fuel caps — even under a $15,000+ Knapheide body.
Can I install it myself or do I need a shop?
You can install it yourself. Basic hand tools, 8 to 15 minutes. No drilling, cutting, or special equipment needed. Many Knapheide dealers and upfitters install them at delivery.
Does it work with all Knapheide models?
Yes — KnapheideService, KUVcc, Utility, Forestry, Crane, and Mechanics bodies. The Fuel Vault mounts to the truck chassis, not the body, so any Knapheide configuration on a compatible Ford or Ram chassis works.
What trucks are compatible?
Ford F-350, F-450, F-550, F-600 Chassis Cab, Ford E-350/E-450, Ford F53 Workhorse, and Ram 3500, 4500, 5500 Chassis Cab.
How much does it cost?
Founders Edition pricing starts at $99.95 with free shipping. Volume discounts available for fleet and dealer orders.
Is there a warranty?
Yes — Limited Lifetime Warranty and a 30-day money-back guarantee on every unit.
Complete Your Knapheide Build — Lock the Fuel
Every compartment on your Knapheide is locked. It's time the fuel cap is too.
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