GarageCove
AN6 One-Way Fuel Check Valve - Anodized Aluminum
AN6 One-Way Fuel Check Valve - Anodized Aluminum
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Fuel that drains back toward the tank when your engine shuts off means hard hot-starts, long cranking, and a fuel rail that has to re-prime every single time. Anyone who has built a custom fuel system, swapped in an aftermarket pump, or run a return-style setup knows how frustrating that lag can be. A dedicated one-way check valve solves it by keeping fuel where it belongs between starts.
This AN6 (6AN) non-return check valve is machined from anodized aluminum to stay light and corrosion-resistant in the engine bay. A spring-loaded internal poppet opens under forward flow and seals firmly against reverse flow, so your line holds prime and your engine fires faster. The directional arrow on the body makes correct installation simple, and the standard 6AN male threads adapt cleanly into common braided and hardline plumbing.
Built for low-pressure carbureted and EFI feed lines, it works with petrol, diesel, ethanol, methanol, E85, and similar fuels, plus oil, coolant, and air setups. The hard-anodized finish resists scuffs and stays sharp-looking, while the compact body tucks neatly into tight routing. A smart upgrade for builders who want consistent priming and tidy, professional-looking lines.
- Standard AN6 / 6AN male threaded fittings, inlet and outlet
- CNC-machined, hard-anodized aluminum body
- Spring-loaded poppet for reliable one-way sealing
- Stops fuel backflow for faster, easier starts
- Compatible with petrol, diesel, E85, methanol, oil, coolant, air
- Directional flow arrow for foolproof installation
- Lightweight, corrosion-resistant, compact footprint
- Ideal for carbureted and low-pressure EFI feed lines
How to use: 1) Match the arrow to your fuel flow direction. 2) Thread into your 6AN line using proper sealant or fittings. 3) Tighten snug, then pressure-check for leaks before driving. For low-pressure fuel systems; not for high-pressure direct-injection lines. Always verify compatibility with your setup and check for leaks before operation.
What Verified Customers Say
Put this on the feed line of my carbed small-block after a fuel system rebuild. Hot starts used to take forever because everything drained back. Now it fires right up after sitting all day. The arrow makes it impossible to install backward.
Running an aftermarket pump on my EFI swap and the rail kept losing prime overnight. This 6AN check valve fixed it completely. Anodizing looks clean and matches my black fittings. Threads were true, no cross-threading.
Used it on a return-style setup on my truck. Solid little piece, the aluminum is light and the spring inside seats firmly. I did wrap the threads properly and pressure tested it, zero leaks. Does exactly what it says.
Bought this for my project car build to keep the lines primed. Machining quality is better than I expected at this price. The flow arrow is clearly marked. Just remember it is for low pressure feed, not high pressure DI.
Got it for my husband who is always tinkering in the garage. He installed it on his diesel build and said it stopped the backflow he was chasing for weeks. He was impressed with the finish and fitment.
Replaced a cheap plastic check valve that was leaking. This aluminum one is night and day sturdier. Held up fine on my E85 setup so far. Snug it down carefully and test before you run it and you will be good.
Shipping
Free shipping on all orders over $50. Orders under $50 ship for a flat $4.95.
- USA & UK: 3–6 business days
- Australia, New Zealand & Europe: 4–7 business days
- Rest of the World: 5–10 business days
Allow 1–2 business days for processing. Tracking emailed when it ships.
Frequently Asked Questions
What is your return policy?
A 30-day money-back guarantee. If it's not the right fit for your setup, reach out for a full refund.
How fast does it ship?
Ships within 1–2 business days. USA & UK 3–6 days, EU/ANZ 4–7, rest of world 5–10. Free over $50.
Is my payment secure?
Yes. Payments are processed securely via Shopify Payments (PCI-compliant, SSL encrypted).
30-Day Money-Back Guarantee
Not satisfied? Return within 30 days of delivery for a full refund. No questions asked.
