Product Specifications – This diesel common rail fuel injector block-off cap set includes 5 pieces with various sizes: 12mm (M12 x1.5), 14mm (M14 x1.5), 16mm (M16 x1.5), 18mm (M18 x1.5), and 20mm (M20 x1.5). Each cap features internal thread sizes and thread intervals of 1.5, with inner diameters corresponding to each size (12mm, 14mm, 16mm, 18mm, and 20mm). Vehicle Compatibility – The fuel caps are designed to fit various diesel engines. The 12mm fuel cap fits Ford 6.4L (2008-2010). The 14mm fuel cap fits Ford 6.7L (2011-2022), Cummins 5.9L (2003-2009), Duramax 6.6L (2001-2005 and 2017-2022). The 16mm cap fits Cummins 6.7L (2019-2022). The 18mm cap fits Duramax 6.6L (2011-2016). The 20mm cap fits Cummins 6.7L (2007-2018) and Duramax 6.6L (2006-2010). These caps are also compatible with other vehicles with similar-sized fuel line nuts. High-Quality Construction - These injector rail fuel line cap block-off tool sets are made from full carbon steel for enhanced durability and long service life. Efficient Functionality – These diesel rail fuel injector block-off caps are designed to effectively block fuel supply to cylinders or seal the common rail pipe. This helps in diagnosing engine issues, such as identifying faulty diesel injectors or troubleshooting engine knock sounds by isolating each cylinder. Easy-to-Follow Instructions – To use, simply remove the diesel fuel injection line from one cylinder at a time and install the corresponding cap on the fuel rail. Increased fuel pressure indicates the faulty injector. Multiple block-off tools can be useful, as multiple injectors returning small amounts of fuel may mimic symptoms of a single injector with excessive fuel return.

Package Includes:

1x 5pcs Diesel Common Rail Fuel Injector Block-off Caps (12MM/14MM/16MM/18MM/20MM).

Fuel Caps Specifications:

M12 (12mm) Fuel Rail Cap: Inner Diameter: M12, Thread Interval: 1.5, 12mm internal thread nuts.

M14 (14mm) Fuel Rail Cap: Inner Diameter: M14, Thread Interval: 1.5, 14mm internal thread nuts.

M16 (16mm) Fuel Rail Cap: Inner Diameter: M16, Thread Interval: 1.5, 16mm internal thread nuts.

M18 (18mm) Fuel Rail Cap: Inner Diameter: M18, Thread Interval: 1.5, 18mm internal thread nuts.

M20 (20mm) Fuel Rail Cap: Inner Diameter: M20, Thread Interval: 1.5, 20mm internal thread nuts.

Vehicle Compatibility:

M12 (12mm) Fuel Rail Cap: Fits for Ford 6.4L 2008-2010.

M14 (14mm) Fuel Rail Cap: Fits for Ford 6.7L 2011-2022; Fits for Cummins 5.9L 2003-2009; Fits for Duramax 6.6L 2001-2005; Fits for Duramax 6.6L 2017-2022.

M16 (16mm) Fuel Rail Cap: Fits for Cummins 6.7L 2019-2022.

M18 (18mm) Fuel Rail Cap: Fits for Duramax 6.6L 2011-2016.

M20 (20mm) Fuel Rail Cap: Fits for Cummins 6.7L 2007-2018; Fits for Duramax 6.6L 2006-2010.