Gates 31856 Fuel Tank Cap

Gates 31856 Regular Locking Fuel Cap

The Gates 31856 regular locking fuel cap is built for vehicles that use a quick-on, pressure-vacuum style fuel cap with a locking design. It is made to meet OEM specifications and emission requirements while helping the fuel system maintain proper tank pressure and vacuum balance.

Key Features

• Lockable fuel cap design for added fuel tank security
• Regular fuel cap style with quick-on cam type
• Pressure-vacuum venting helps the tank breathe while limiting fuel vapor escape
• Built to meet OEM specifications and Federal and State emission requirements
• Thread diameter: 1.77 in; shell diameter: 2.91 in; depth: 2.47 in

Product Details

This Gates Regular Locking Fuel Cap, part number 31856, is a direct-fit style fuel tank cap for select Ford, Volvo, Mazda, Land Rover, and Jaguar applications. It uses a pressure-vacuum valve to manage tank breathing during normal fuel system operation, which helps maintain the sealed fuel system required for emissions control. The Gates 31856 is a practical replacement for drivers needing a locking fuel cap with the correct quick-on fit and venting profile.

Compatible vehicle applications include the 2010-2013 Ford Transit Connect, 2008-2013 Volvo C30, 2006-2013 Volvo C70, 2004-2011 Volvo S40, 2005-2011 Volvo V50, 2006-2010 Mazda 5, 2005-2009 Land Rover LR3, 2004-2009 Mazda 3, 2009 Mazda 3 Sport, 2005-2008 Jaguar S-Type, and 2001-2007 Jaguar X-Type. This part cross-references Four Seasons 35080 for the same application.

Common Issues This Part Can Address

• Loose, damaged, or missing locking fuel cap
• Fuel vapor odor caused by a worn cap seal or venting issue
• Check engine light related to evaporative emissions sealing faults
• Difficulty maintaining proper fuel tank pressure or vacuum balance
• Replacement need after cap threads, cam, or locking mechanism wear

Installation Notes and Tips

Confirm the cap style, thread diameter, and venting type before installation. This part uses a quick-on cam design and is listed for vehicles with a regular locking fuel cap application; the 2001-2007 Jaguar X-Type note specifies use without a threaded filler neck. Make sure the filler neck is clean and undamaged so the cap can seal correctly.

Quality Assurance

Gates states this fuel tank cap meets OEM specifications and Federal and State emission requirements. The pressure-vacuum valve design supports proper fuel system breathing while helping reduce fuel vapor escape.