21577507 Genuine Mack DEF Pump Unit

DESCRIPTION DEF Pump Unit CONDITION Used BRAND Mack PART NUMBER 21577507 Cross-reference note: Part number 21577507 is a matching cross-reference for our main listing part number 21577511. Function of this partThe aftertreatment system treats exhaust gases after they leave the engine using components such as the DOC, DPF, and SCR catalyst. It controls soot and NOx emissions by trapping particulates and converting harmful gases into less harmful compounds. Why this part mattersThese components are central to emissions compliance on modern diesel trucks. Problems in the aftertreatment system can cause frequent regens, power derates, and down-time until the fault is corrected. About the brandMack is known for building tough trucks and components for construction, vocational, and highway fleets that need reliable performance day after day. Fitment & usage Used OEM parts are a smart choice for controlling repair costs while still using original-equipment components. Always match the OEM part number(s) listed to your existing part, and consult your service manual, dealer, or technician if you are unsure about fitment. Note: Because this is a used component, normal signs of wear such as scratches, discoloration, or light surface corrosion may be present. Refer to the product photos and information on Second Truck Parts for the best representation of the part you will receive.