Trucks / Ram / DEF Pump / 4500
Used Ram 4500 DEF Pump for Sale
- OEM used part
- Quality tested
- Fits 2013–2024
- Ready to ship
- 30-day warranty
A Ram 4500 with a DEF pressure code is on a derate countdown, and a dealer back-order doesn’t stop the clock. We stock used OEM DEF pumps for Ram 4500 trucks (2010 and newer), tested for pressure build and covered by our warranty. Send your VIN, engine and the codes and we confirm the match before you pay.
How it works
This part is in our inventory and ready to ship. Share your VIN and we confirm fitment before you buy, then we’ll call you within about 30 seconds with your quote — or email it if we can’t reach you.
Signs your def pump has failed
- DEF/SCR warning lamp with a derate countdown, or a speed limit already active
- P20E8 (reductant pressure too low), P204F or P208A (reductant system performance / pump control)
- DEF pump won’t prime — no hum at key-on
- Crystallized DEF at the pump, filter or lines
- DEF pressure builds, then collapses
- Repeated failed DEF quality or regen cycles after a refill
Before you order
- Send your VIN and engine — DEF supply modules are engine- and year-specific, and Isuzu, Ford, GM, Ram and Fuso each use different units.
- Check the DEF filter (where serviceable), the lines for crystallization, and the pump’s power and ground before condemning it.
- Use fresh ISO 22241 DEF from a sealed container after replacement — old or contaminated DEF is what killed the original.
- A scan-tool reset/relearn of the SCR system is typically required after the swap; the derate clears once the system passes its self-test.
Other Ram 4500 parts
Frequently asked questions
Do you sell used DEF Pump for all medium-duty truck brands?
Yes — we carry used def pump units for Isuzu, Ford, Chevrolet, GMC, Ram, and Mitsubishi Fuso medium-duty trucks, not just the Ram 4500.
Is this used DEF Pump tested before it ships?
Yes. Every def pump we sell is inspected and tested before it ships, so it works right the first time.
How do I order this DEF Pump?
Request a free quote above or call us. Share your VIN and we’ll confirm exact fitment, then call you back with a quote in about 30 seconds — if we can’t reach you, we’ll email it instead.
Do you offer a warranty on this DEF Pump?
Yes, we stand behind this def pump with our warranty. Exact terms are confirmed on your quote.
Do you ship this DEF Pump nationwide?
Yes — we ship to all 48 contiguous states with tracked delivery. Most parts arrive in 3–7 business days; engines, transmissions and axles ship freight and typically arrive in 5–10.
Will a used DEF pump clear the derate?
If the fault is the pump, yes — after installation and the SCR system reset, the truck runs its self-check and the countdown clears. If the code is a NOx sensor, DEF injector or quality sensor, it won’t; our DEF guide narrows it down.
Are used DEF pumps tested?
Every DEF pump is checked for pressure build before it ships.