Fuel Odor or Leak from Top of Fuel Tank

A fuel odor, fuel leak or fuel weeping may be noticed at the top of the fuel tank on some 2015-2016 Colorado and Canyon trucks. This condition may be caused by chemicals being carried in the truck bed.


Sulfuric acid, such as from leaking batteries, or other chemicals placed in the bed of the truck may leak or be washed through the holes in the pickup box and settle on the top of the fuel tank. As a result, chemical damage to the fuel pump module may be seen as a fractured port (Fig. 18) or cracks in the plastic flange. (Fig. 19)


F18 fuel pump 1a

Fig. 18


F19 fuel pump 1

Fig. 19

Vehicles with a spray-on bed liner also may exhibit the condition because the floor/front panel seam is not fully sealed.


Verify fuel pump damage or failure and replace the fuel pump module.


Before reinstalling the fuel tank to the vehicle, install a drain hole plug to the open left side drain hole location. (Fig. 20)


F20 fuel pump 2Fig. 20

After installation of the new fuel pump module, apply seam sealant to the top-side front joint of the pickup bed floor and front panel.


Clean any dirt, grease, or chemical residue from the repair area. Apply clear seam sealer to the bed floor or black sealer on a spray-on bed liner. Ensure the lower corners are fully sealed by applying sealant past the bottom radius and up to the front panel body line (Fig. 21) as well as across the complete front/floor panel joint. (Fig. 22)


F21 fuel pump 3

Fig. 21

F22 fuel pump 4

Fig. 22


Refer to Bulletin #16-NA-195 for additional details, including seam sealer parts information.


– Thanks to Charles Hensley



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