8AN Roll Over Vent Valve: Setup Tips for Fuel Systems
By DeatschWerks | Published: 2026-11-01
Category: Tips & Care
Learn how to install an 8AN roll over vent valve correctly. Follow these steps for safe fuel tank venting, proper plumbing, and common mistake checks.
Quick Answer
Mount the 8AN roll over vent valve high in the fuel system vent line, use compatible 8AN plumbing, and route the vent outlet away from heat and debris. Always check for proper orientation and leak-free connections before filling the tank.
Why Vent Valve Placement Matters
A roll over vent valve protects against fuel spillage if the vehicle flips, but only if it's mounted correctly. Placing it at the highest point in the vent line ensures it can close when needed and allows normal venting during operation. Avoid low spots where fuel could pool and interfere with the valve's function.
Common Plumbing Mistakes to Avoid
Using the wrong fittings or over-tightening can damage the valve or cause leaks. Always use 8AN compatible fittings and follow torque specs if provided. Also, avoid routing the vent line near exhaust components or moving suspension parts that could wear through the hose.
Step-by-Step Installation Guide
- Choose the mounting location: Select a spot as high as possible in the vent line, away from heat sources and moving parts. Ensure the valve is oriented according to the manufacturer's instructions (if provided). Double-check clearance from exhaust and suspension components.
- Prepare the 8AN plumbing: Cut and deburr the vent hose to length. Install appropriate 8AN fittings on the hose ends, following fitting manufacturer's instructions. Use a hose cutter for clean cuts; avoid jagged edges that can cause leaks.
- Mount the valve: Secure the valve using a bracket or clamp, ensuring it is not stressed by the hose. Connect the inlet and outlet ports to the vent line. Verify the valve is not upside down; most roll over valves have a specific orientation.
- Connect and tighten fittings: Thread the 8AN fittings onto the valve by hand, then tighten to the recommended torque if available. Avoid over-tightening to prevent damage. Check for any cross-threading before tightening.
- Route the vent outlet: Direct the vent outlet away from fuel sources, heat, and debris. Use a hose to route it to a safe area, such as under the chassis. Ensure the outlet cannot be clogged by dirt or water.
- Test for leaks and function: Refill the tank and check for leaks at all connections. Gently rock the vehicle to simulate rollover and confirm the valve closes (if accessible). Perform a final visual inspection after the first drive.
Product Facts
- 8AN Roll Over Vent Valve: 8AN fitting size for compatible plumbing. Ensures direct connection to 8AN lines without adapters, reducing leak points.
8AN Roll Over Vent Valve - 8AN Roll Over Vent Valve: Roll over vent valve design for fuel system venting. Provides safety by closing off the vent in case of vehicle rollover.
- 8AN Roll Over Vent Valve: Anodized matte black finish. Offers corrosion resistance and a clean look under the hood.
