What This Hose Is and Where It Lives
This is a molded silicone reducer coupler, aramid-reinforced with a stainless steel support ring molded in at the larger end. It's not a straight piece of tubing - it's stepped, 57mm on one end tapering to 48mm on the other, built to handle the constant thermal cycling and pressure pulses coming off the EGR system on an ISX15.
You'll find it in the EGR cooler-to-intake piping runs, wherever Cummins needed to transition pipe diameters. It sees exhaust gas heat on one side and has to seal tight enough not to leak boost or EGR flow on either end. That combination is why they use aramid-reinforced silicone instead of just running a rubber coupler - regular rubber cooks and cracks in that environment within a year or two.
Confirm you've got the right one by checking the ID on both ends of your old hose (57mm and 48mm) and the overall length before you order. EGR plumbing gets modified across engine years and applications, so don't assume - measure or pull the number off the old part if it's still legible.
How the Cross Numbers Line Up
3687223 is the Cummins number, and it's what shows up in most parts lookups and manuals for ISX15 EGR service. The aftermarket numbers - 561.90223, CUM38601, F02486S352 - all reference this same hose geometry: same ID steps, same reinforcement, same ring placement. These aren't random substitutes; different suppliers just stamp their own part numbers on hoses built to the same spec.
Where you need to pay attention is the stainless ring position and the overall hose length. Some ISX applications have slightly different mounting clearance depending on chassis and cooler placement, so a hose that crosses correctly on paper can still need trimming or a different clamp spacing to seat right. If your old hose has a visible ring or bead pattern, compare it against what you're ordering before it goes in the truck.
When in doubt, pull your engine serial number or the casting number off the old hose and call us. We'd rather spend two minutes confirming than have you install it and find out the ring's in the wrong spot.
Ordering From PartStop
We keep this hose in stock at the Tacoma counter for the ISX15 crowd - Roadway trucks, apply here. If you're local and need it same day, call ahead and we'll have it up front. Otherwise we ship nationwide, usually out the door same business day if you order before early afternoon.
At $38.99 it's a small line-item next to an EGR cooler bill, but a bad reducer hose can dump coolant or let boost leak past just as easy as a bad cooler can. Worth replacing both if you're already in there.
Every hose we sell carries our 6+ month warranty. If it fails from a defect in that window, bring it back or call us - we'll sort it out. Just verify fitment against your VIN or old part number before installing; we can't take back a hose that's been clamped down and run.
3687223 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to 3687223. 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 |
|---|---|
| Aftermarket | 561.90223, CUM38601, F02486S352 |
Frequently asked questions
Does 3687223 fit my 2016 ISX15?
Likely, but confirm by checking the ID on both ends of your old hose (57mm/48mm) and comparing overall length. EGR routing changed some across ISX15 model years, so pull the old part's number if you can still read it, or give us your VIN and we'll check the application.
Is this the same as the CUM38601 hose?
Same hose geometry and reinforcement - CUM38601 crosses to this same 57mm-to-48mm reducer with the stainless ring. Different supplier's part number, same spec. Just double-check the ring placement and length match your old hose before installing.
How do I know if this hose is actually bad versus just dirty or oily-looking?
Squeeze it cold - if it's stiff, cracked, or has a bulge near the ring, replace it. Oily residue alone doesn't mean it's shot, but combined with any hardness or visible cracking at the clamp areas, it's done. Don't wait for it to blow apart on the road.
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.