Paccar Kenworth T800 2012, Manual

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08/12
4-1
Section 4
Exhaust & Aftertreatment
Exhaust and aftEr-trEatmEnt InformatIon
The following section is designed to give you information regarding the exhaust and after-treatment systems on Kenworth
chassis.
All Kenworth’s equipped with 2010 emission level engines will utilize Selective Catalyst Reduction (SCR). SCR is a
process in which Diesel Exhaust Fluid (DEF) is injected into the exhaust down stream of the engine. DEF is converted to
ammonia by the heat of the exhaust system. Inside of the SCR canister a catalyst causes a chemical reaction to occur be-
tween the ammonia and NOx, turning it into water and nitrogen. For more information on the specific details of how SCR
works, please contact your local Kenworth dealer.
dEf system schematic:
On most Kenworth chassis the DEF Supply Module (or pump) is integrated into the DEF tank. Kenworth does not allow
relocation of this pump. The following schematic details how the DEF lines route to the after-treatment system.
DEF Return Line
(Backflow from
Supply Module)
Coolant Draw
(from Draw Tee)
detail a
scale 1:2
DEF Draw Line
(Inlet to Supply Module)
Coolant Return
(to Coolant Valve)
DEF Tank
(10-gallon shown)
See Detail A
DEF Return Line (Backflow)
DEF Draw Line (Inlet)
DEF Supply Module
(Pump)
DEF Pressure Line
(Outlet)
DEF Dosing Module
(Injector)