What This Hose Is and Where It Goes
This is a 9-hump silicone reducer hose - it steps down from 100mm to 83mm over 400mm of length, built for the charge air cooler piping on Volvo and Mack trucks and buses using the F02492S352 configuration. The multiple humps let the hose flex with engine movement and vibration without splitting like the stiffer OE rubber does after a few years of heat cycling.
Silicone holds up better than rubber under the boost pressure and underhood temps these CAC systems see, especially once the truck's got 200k+ miles and the rubber starts going brittle. If your old hose is cracked at the humps or soft and swollen, that's your sign it's time.
This isn't a universal hose - the 100mm-to-83mm reduction and 400mm length are specific dimensions, so don't grab this thinking it'll work on a straight-through or different reducer setup.
Reading the Cross-Reference Numbers
21312237 is the Volvo number this part replaces, and it crosses to 20589123, 20574218, 8149800, and 1665556 - these are all Volvo part numbers that have superseded each other over the years as Volvo updated their numbering system. Same hose, different catalog eras.
Where guys get tripped up is assuming any 100mm-to-83mm reducer hose will bolt in. It won't necessarily - hump count, hump spacing, and overall length all have to match your specific CAC routing. A hose that's 350mm instead of 400mm, or has 7 humps instead of 9, might look close enough on a shelf but won't seat right or clamp up properly.
Bottom line: pull the number stamped or molded on your old hose, or run the chassis VIN, before you order. If your old hose is unmarked or the number's worn off, measure hump-to-hump and overall length yourself and match it against this listing.
Ordering From PartStop
We're in Tacoma and keep this one in stock for same-day pickup or local delivery if you're in the area. If you're outside Washington, we ship nationwide and most orders go out same day or next business day.
At $91.99 this is a straightforward swap - no special tools beyond a hose clamp set and maybe a heat gun if the old one's stuck. Comes with our standard 6+ month warranty against defects.
If you're not 100% sure this is the right reducer for your setup, give us a call with your VIN or the old part number before you order. Cheaper to make one phone call than to eat a restocking fee on the wrong hose.
21312237 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to 21312237. 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 | 20589123, 20574218, 8149800, 1665556, F02492S352 |
Frequently asked questions
Does 21312237 fit my 2015 Volvo VNL with a D13?
Likely, but confirm with your VIN or pull the number off your old hose first - Volvo used several CAC configurations across those model years and engine combos, and this is the F02492S352 reducer setup specifically. Don't guess off the year alone.
Is this the same as Volvo 8149800?
Yes, 8149800 is one of the earlier Volvo numbers that crosses to this same hose - Volvo's renumbered this part a few times over the years (8149800, 1665556, 20574218, 20589123 all lead back to the same physical part). If your old hose has any of those numbers stamped on it, this is your replacement.
How do I know if I need the 100mm-to-83mm reducer versus a straight hose?
Measure both ends of your old hose or CAC pipe - if one side's noticeably bigger than the other, you've got a reducer. If they're the same diameter, you need a straight-through hump hose instead. When in doubt, bring the old part in or send us a photo with a tape measure on it.
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.