What This Pump Does and Where It Lives
This is the DEF metering pump/module that pulls fluid out of the tank and pushes it up to the injector in the exhaust stream ahead of the SCR cat. It's not just a pump — there's a filter, pressure sensor, and heater circuit built into the unit, so when one part fails you're usually replacing the whole module.
Fits Detroit Diesel DD13 and DD15 engines in Freightliner Cascadias, roughly 2017 through 2024 model years depending on when Detroit updated the part mid-run. Location's the same across those years — driver's side frame rail, tucked up near the DEF tank.
Reading the Cross-Reference Numbers
RA0001407278 and A0001407278 are the same part — the 'R' prefix is just how Freightliner tags it as a reman/service unit versus the straight OEM A-number. Detroit's own numbering runs a string of similar parts (A0001404778, A0001405578, A0001407078, A0001407778, A0001408078, A0011400678) because they revised the pump several times over the production run — usually software calibration or connector changes, not a physical redesign.
The EA-prefix numbers (EA0001408078, EA0001407278, EA0011400678) are Detroit's OEM designation for the same physical pump — don't let the extra letter throw you, it doesn't mean it's a different part. Where you can get burned is the electrical connector pinout and the mounting bracket bolt pattern — those did change across some of these numbers, so a pump that bolts up fine on a 2018 might not plug into the harness on a 2022 without an adapter.
Bottom line: match the number stamped on your old pump housing, not just the model year of the truck. If the tag's worn off, pull the truck's VIN and call us — we can run it through Freightliner's system and confirm which pump the build sheet calls for.
Ordering From PartStop
We stock this one in Tacoma and it ships same-day if you call before early afternoon. If you're local, come grab it off the shelf — DEF system faults usually mean a truck sitting, and nobody wants to wait on ground shipping for that.
Every pump we sell carries our 6+ month warranty. Aftermarket reman units like this go through bench testing before they leave the supplier, but electronics being what they are, we'd rather back it than pretend nothing ever fails out of the box.
RA0001407278 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to RA0001407278. Use them to identify the part — then confirm the exact fit by VIN or the number stamped on your old unit before you order. An interchange is a starting point, not a fitment guarantee.
| Brand / Line | Cross-Reference Numbers |
|---|---|
| Freightliner (OEM) | A0001407278 |
| Detroit Diesel | A0001404778, A0001405578, A0001407078, A0001407778, A0001408078, A0011400678 |
| Detroit Diesel (OEM) | RA0011400678, EA0001408078, EA0001407278, EA0011400678 |
Frequently asked questions
Does RA0001407278 fit my 2020 Cascadia with the DD15?
Likely, but confirm by the number on your old pump or your VIN before you order. Detroit ran several revisions of this pump across 2017-2024, and while most cross to RA0001407278, connector and bracket differences on some years mean it's worth a quick check rather than a guess.
Is this the same as the Detroit OEM EA0001407278 pump?
Yes — EA0001407278 is Detroit's OEM part number for the identical physical pump. The E prefix is just their internal designation, it's not a different design or a lesser part.
My old pump has A0011400678 on it — will RA0001407278 bolt in as a replacement?
Those two cross-reference to each other and are generally considered a direct replacement, but A0011400678 was one of the later revisions with a slightly different connector on some builds. Pull your old unit and compare the plug before you order, or call us with the VIN and we'll verify.
Not sure it fits? We check before you pay.
Run your VIN and we’ll match parts to your exact truck, or call the counter — a person who knows trucks verifies fitment by OEM number before the order ships. No wrong-box returns.
More cross-reference guides
Need the part, not just the reading?
Every part below is a Premium Quality aftermarket Direct Replacement with published OEM cross-reference numbers, a 6+ month warranty and same-business-day shipping from Tacoma, WA. Not sure it fits? Run your VIN — or call and a person who knows trucks will verify fitment before you pay.