DuraWRX DEF Header for Freightliner Detroit Engines, Analog SAE Tank Header, 20" Height is a direct-fit replacement header assembly designed to restore in-tank DEF level sensing and fluid handling for Freightliner vehicles using Detroit Diesel SCR systems. This header integrates an analog level sensor and tank connections built to SAE flange and SAE J2044 fitting standards, delivering the interface points necessary for accurate DEF level reporting and in-tank filtration. The assembly includes a 70μ in-tank filter and matching suction and return fittings sized for common DEF plumbing, along with coolant nipples for heater interface. By replacing a degraded or failed header assembly, fleets re-establish reliable tank-level feedback to vehicle electronics, reducing false low-level warnings, unnecessary vehicle service events, and potential downtime associated with interrupted selective catalytic reduction (SCR) dosing protocols. Technicians can install the header as a plug-and-play unit, restoring the tank s sensor, filter and fluid connections without reworking vehicle harnesses or lines. For operations that depend on predictable uptime and scheduled maintenance windows, this header helps return vehicles to compliant DEF monitoring and keeps the DEF system s circulation and heater circuit accessible for normal operation. The header s analog sensor type and standard electrical connector format provide straightforward integration with existing Detroit control modules and wiring harnesses. Specified fittings and the SAE J2587 flange interface make the assembly suitable for standard Freightliner DEF tanks sized for 13- and 23-gallon configurations. Choosing a purpose-built replacement header minimizes time in the bay, simplifies parts stocking decisions, and restores the functional elements needed to support SCR emissions control; technicians receive a fully assembled in-tank solution that replaces worn components and returns the vehicle to serviceable DEF system operation.