Does the RV Fuel Vault Fit a Dynamax Motorhome?
Yes. The RV Fuel Vault fits Dynamax Super C motorhomes — including the Isata 6 on the Ford F-600, the Force HD and DX3 on Ford, and the gas Isata 5 on the Ram 5500.
Which Dynamax models does it fit?
The RV Fuel Vault is engineered for the commercial Ford (and Ram) chassis that Dynamax motorhomes are built on. Here is how the lineup breaks down:
| Chassis | Dynamax models |
|---|---|
| Super C (Ford F-550 / F-600 diesel) | Isata 6 (F-600), Force HD, DX3 |
| Super C (Ram 5500 gas) | Isata 5 |
Not sure which one you have? The fitment finder confirms your exact year, make, model, and floorplan in seconds.
Why Dynamax owners need it
Dynamax coaches sit on heavy-duty commercial chassis with large fuel tanks and exposed fuel caps — plus an exposed DEF fill on newer Isata 6 coaches. That combination is exactly what fuel thieves look for. The RV Fuel Vault is engineered for both the Ford and Ram 5500 commercial filler areas, where standard automotive locking caps simply do not fit.
- Stops fuel theft & siphoning — a keyed, virtually unbreakable door over the cap.
- Prevents contamination — no more open access to add water, sugar, or the wrong fluid.
- Built tough — 3/16″ fiber-filled polymer that is non-corrosive and resists prying.
- Factory-finished look — covers the ugly exposed cap for a clean, finished appearance.
Installation & pricing
The RV Fuel Vault is a bolt-on upgrade that most owners install in 8–15 minutes with basic hand tools — no drilling, no cutting, and no permanent modifications. A single small door is $159.95, a set of two is $319.95, and the 3-Pack with the DEF door is $479.95. Shipping is calculated at checkout. Every order is backed by a Limited Lifetime Warranty and a 30-day satisfaction guarantee.
Frequently asked questions
Does the RV Fuel Vault fit a Dynamax Isata 6?
Yes. The Isata 6 is built on the Ford F-600 chassis. The factory setup takes 2 small doors for the two driver-side fuel caps. 2026 coaches retrofitted with the DEF fill moved to the outside front, driver side, and all 2027–2028 models take the 3-Pack: 2 small doors plus 1 round door for the DEF fill.
Does it fit a Dynamax Isata 5 on the Ram 5500?
Yes. The Isata 5 is a gas coach on the Ram 5500. It takes 1 small door plus the single-door security screw pack.
What does it cost and how long is the install?
A single small door is $159.95, the 2-Pack is $319.95, and the 3-Pack with the DEF door is $479.95. Shipping is calculated at checkout. Most owners install it in 8 to 15 minutes with basic hand tools.
Lock down your Dynamax fuel cap
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More answers about the RV Fuel Vault
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