6 Duramax Fuel Filter Replacement & Water-Separator How to replace the fuel filter and drain the fuel water separator on a 6 Duramax. Covering 2001 to 2016 model year, these procedures detail removal and installation of a new fuel filter on any 6 Duramax diesel in addition to draining the fuel water separator. duramax fuel filter plug | eBay Find great deals on eBay for duramax fuel filter plug. Shop with confidence. Skip to main content. eBay Logo: New Genuine GM Fuel Filter Drain Valve Plug 19121759, 1 product rating - Gold Plug 8200 Billet Air Bleeder Screw for 2001-2016 GM Duramax Fuel Filter. $23. FAST 'N FREE. Buy It Now. Estimated delivery Thu, May 16.