NAVISTAR part description. TANK,DEF , 9.5 GAL, HEAD UNIT, Navistar ® is a proud manufacturer of some of the widely used trucks, yellow school buses, defense vehicles, and engines. It was recognized as the first truck and engine manufacturer to be certified by the EPA for meeting 2007 standards for hydrocarbons and particulate matter. View photos, details, and other Diesel Exhaust Fluid (DEF) Tanks for sale on MyLittleSalesman.com. Stock # BB-0660-8, MLS # 10879494. Saved (0) My Account. Sign in Sign up. Control Center. Dashboard. Buyer Tools. ... Cummins Def Sender unit P/N 4254214C91 call for details we ship everywhere., Air/Hydraulic: Air/Hydraulic, VIN.