Gates 31828 Fuel Tank Cap

Gates 31828 Regular Locking Fuel Cap

The Gates 31828 Regular Locking Fuel Cap is a direct-fit fuel tank cap for select Ford, Lincoln, Mercury, and Mazda applications. It is built to meet OEM specifications and emission requirements while helping seal the fuel system against vapor loss.

As part of the Gates Regular Locking Fuel Cap line, this cap combines a lockable design with emission-control venting and a two-way pressure relief/vacuum relief valve. That means the tank can breathe as fuel level and temperature change, while helping reduce fuel fumes escaping from the system.

Key Features

• Lockable fuel cap design for added fuel tank security
• Emission-control venting to support evaporative emissions compliance
• Two-way pressure relief and vacuum relief valve
• Quick-On cam type for the listed applications
• Regular fuel cap style with a 1.77 in thread diameter
• Shell diameter: 2.91 in; depth: 2.48 in
• Gates part number 31828 for application matching

Detailed Description

This fuel tank cap is engineered for vehicles that use a regular locking fuel cap and a Quick-On style interface. It is a practical replacement for worn, missing, or damaged caps on models such as the Ford F-150, Ford Expedition, Ford Mustang, Lincoln Town Car, and Mercury Grand Marquis. The Gates 31828 is also listed for multiple Ford truck, SUV, and passenger car applications across the 1996-2006 model years.

This part cross-references FEL-PRO 35066 and CSF 10502 for the same application. Use the fitment data to confirm whether your vehicle requires the regular locking fuel cap version or a specific OE-style black-bottom cap note.

What It Helps Solve

• Fuel odor caused by a cap that no longer seals properly
• Check-engine concerns related to evaporative emissions faults
• Loose, damaged, or missing locking fuel cap hardware
• Vapor leakage from a worn cap seal or valve assembly
• Fitment issues on vehicles requiring a regular locking fuel cap

Installation Notes and Tips

Verify the filler neck style, locking requirement, and OE cap notes before ordering. This cap is listed for applications including 1999-2005 Ford F-250 Super Duty, 1999-2005 Ford F-350 Super Duty, 2000-2006 Lincoln LS, and 1997-2004 Ford Expedition, with additional fitment across Ford, Lincoln, Mercury, and Mazda models. For some vehicles, the notes specify use without a threaded filler neck or for a black-bottom OE cap.

Before installation, compare the existing cap’s cam type, thread diameter, and shell diameter to the product specifications. After installation, tighten the cap until it locks securely and confirm that the fuel door or cap area closes correctly.

Quality Assurance

Gates states that this locking fuel tank cap meets OEM specifications and Federal and State emission requirements. The emission-control valve design is intended to maintain tank breathing while helping limit fuel vapor escape.