What This Tank Is and What It Fits
This is the coolant recovery/overflow reservoir, not the radiator itself. It sits off to the side, takes the overflow from the cooling system when things heat up, and feeds it back in as the engine cools down. Plastic tank, molded-in mounting tabs, hose barbs on top and bottom.
Volvo and Mack share a lot of cab and chassis parts thanks to the corporate family tree, so this tank shows up on Volvo VN, VNL, and VNM models roughly 2008 through 2021, and on comparable Mack Pinnacle/Anthem trucks running the same cooling architecture. It's a long production run, so there were running changes — different tank capacities, slightly different mounting bosses depending on model year.
Because of that, 20881601 isn't a one-size-fits-every-VNL number. It's the number for a specific window of trucks and configurations, and you need to nail it down before you order.
Why These Numbers Cross and What to Double-Check
20881601 is the Mack-side number, and it cross-references to Volvo OE 23915461 and 21074569, plus aftermarket equivalents like Newstar S-22162 and SKP SK6035505. These aren't coincidence — Volvo Group builds these tanks for both nameplates off the same tooling, then stamps different part numbers depending on which parts book it lands in.
Where guys get burned is capacity and neck fitment. There were at least two tank sizes used depending on cooling package (standard vs. high-capacity radiator), and the fill neck/cap thread can differ between early and late production. A tank that bolts up fine can still have the wrong neck height or hose barb angle if you grab the wrong year's version.
Don't order off the truck's model year alone. Pull the number stamped or molded into your old tank — it's usually near the base or on a flat spot — and match it against this list. If it's unreadable, VIN-check it against the chassis before you buy. That's the only way to be sure with this much overlap between Volvo and Mack part books.
Ordering From PartStop
We're in Tacoma and keep this tank in stock — if you're local and your VNL is sitting with a cracked reservoir, same-day pickup or delivery around town is doable. Call ahead so we can have it ready.
Ship nationwide too, standard ground or expedited if a truck's down and you need it faster. Comes with our 6+ month warranty, so if something's off with the part itself, we'll deal with it.
Before you check out, give us the old tank's number or your VIN. Takes two minutes and saves you a return shipping headache on a $299 tank.
20881601 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to 20881601. 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 |
|---|---|
| Volvo OE | 23915461, 21074569 |
| Mack OE | 376923031 |
| Newstar | S-22162 |
| SKP | SK6035505 |
Frequently asked questions
Does 20881601 fit my 2015 VNL 670?
Likely, but confirm before ordering — 2015 falls in the middle of that model run where cooling packages varied. Check the number on your old tank or give us the VIN and we'll match it to make sure it's the right capacity and neck style.
Is this the same as Volvo 23915461?
Same physical tank, different part number stamped for the Volvo parts book versus the Mack one. They cross-reference to each other, but always confirm against your old part number since there were multiple tank versions used across these model years.
My old tank has no readable number — how do I know I'm getting the right one?
Send us your VIN. We can look up the cooling package and confirm which tank version your truck left the factory with, which is more reliable than guessing off a cracked or sun-faded part number.
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.