Buy Genuine Detroit Diesel DEF Pump DD13/DD15 - wisentpartscenter.com

Description

Detroit Diesel A0001404378 DEF Pump - Genuine Detroit Diesel Exhaust Fluid Pump for DD13 and DD15

The Detroit Diesel A0001404378 is a genuine DEF pump. It pulls diesel exhaust fluid from the tank and pushes it to the doser at the pressure the aftertreatment needs, then purges the lines back at shutdown so nothing is left to freeze.\

Key Functions:

- Supplies DEF from the tank to the doser at regulated pressure
- Filters the fluid on the way through
- Purges the lines back to the tank at shutdown

Fitment & Specifications:

2014–2022 Freightliner 114SD Truck (Class 3–8) – Detroit Diesel DD13 12.8L

2016–2022 Freightliner 122SD Truck (Class 3–8) – Detroit Diesel DD13 12.8L

2016–2022 Freightliner 122SD Truck (Class 3–8) – Detroit Diesel DD15 14.8L

2014–2022 Freightliner Cascadia Truck (Class 3–8) – Detroit Diesel DD13 12.8L

2014–2021 Freightliner Cascadia Truck (Class 3–8) – Detroit Diesel DD15 14.8L

2014–2015 Freightliner Coronado Truck (Class 3–8) – Detroit Diesel DD13 12.8L

2014–2015 Freightliner Coronado Truck (Class 3–8) – Detroit Diesel DD15 14.8L

2014–2021 Freightliner M2 Truck (Class 3–8) – Detroit Diesel DD13 12.8L

2014–2022 Western Star 4700SB Truck (Class 3–8) – Detroit Diesel DD13 12.8L

2014–2022 Western Star 4700SF Truck (Class 3–8) – Detroit Diesel DD13 12.8L

2014–2022 Western Star 4800SB Truck (Class 3–8) – Detroit Diesel DD13 12.8L

2014–2022 Western Star 4900EX Truck (Class 3–8) – Detroit Diesel DD15 14.8L

2014–2022 Western Star 4900FA Truck (Class 3–8) – Detroit Diesel DD13 12.8L

2014–2020 Western Star 4900FA Truck (Class 3–8) – Detroit Diesel DD15 14.8L

2014–2022 Western Star 5700XE Truck (Class 3–8) – Detroit Diesel DD13 12.8L

2016–2022 Western Star 5700XE Truck (Class 3–8) – Detroit Diesel DD15 14.8L

Note: Verify fitment with us before ordering to ensure the correct part for your application.

Purpose of the Part

Nothing in the SCR system works without pressure at the doser, and this pump is what makes it. The ECM meters DEF assuming the pump is holding steady pressure, so if pressure drops or swings, dosing goes off even with a good doser and good fluid. The reverse purge at shutdown matters just as much, DEF freezes and expands, so pulling it back out of the lines is what keeps them from splitting over a cold night.

Issue Symptoms / When to Replace

DEF pressure faults and derate are the usual complaint. Also low or no pressure at the doser, a pump that runs constantly or not at all, DEF leaks at the fittings and crystal buildup around the pump.

Moisture getting into the electrical side and power supply problems are what take most of these out. Check the connector, supply voltage and grounds first.

Also check the fluid with a refractometer and look in the tank for sediment or crystal before replacing the pump. Contaminated DEF and a dirty tank will kill a new pump the same way it killed the old one.

Brand Information

A genuine pump has everything molded into the housing, not printed or stickered. Look for the Mercedes star with the Daimler number in the A 000 140 77 78 format, the EcoFit marking and the CES supplier number, with the same numbers repeated on the aluminum body underneath. Copies usually leave off the star and EcoFit marking or print the numbers on instead of molding them in.

Installation Notes

1. Relieve pressure in the DEF lines before opening anything.
2. Check the tank for sediment or crystallized urea and flush it if it is dirty.
3. Replace the DEF filter and check the lines for restriction or crystal.
4. Mount the pump with new seals and keep the fittings clean.
5. Make sure the connector is seated and locked, and that voltage and ground are good.
6. Prime the system per the procedure so the pump is not run dry.
7. Verify pressure builds and holds, then clear codes before the truck goes back out.

How to Identify an OEM Part

A genuine pump has everything molded into the housing, not printed or stickered. Look for the Mercedes star with the Daimler number in the A0001404378 format, the EcoFit marking and the CES supplier number, with the same numbers repeated on the aluminum body underneath. Copies usually leave off the star and EcoFit marking or print the numbers on instead of molding them in.

Why Buy A0001404378 from Wisent Parts

  • ⏱️
    Fast shipping
    Orders before 12PM EST ship same business day.
  • 🛡️
    180-day warranty
    All parts covered from delivery date.
  • ↩️
    Easy returns
    30-day returns.
  • ✅
    Verify fitment
    Send VIN/ESN and we’ll confirm.

Shop with confidence

Warranty & Return Information
Warranty Information

Wisent Parts offers a 180-day warranty on all parts from the date of delivery. This warranty covers orders placed directly through our website. If a part fails during this period, we’re here to help - whether it’s a replacement, repair, or refund. For full details, refer to the Warranty page.

Return Information

Wisent Parts accepts returns within 30 days of delivery. All returns are subject to a restocking fee. To qualify, parts must be unused and in their original condition. For full return instructions and restocking fee details, please refer to the Returns page.