Class 8 Orders Up 150%: Aftermarket Stock Moves First

A shop called. They needed a hydraulic brake hose for a 2014 Peterbilt. You checked the shelf, then the reorder list, then the shelf again. Not there. So the shop called the next supplier on their list, and that sale is gone. Your reorder list, by the way, is still sorted by part number, built from last year's sales.

Here's the strange part: this is exactly the year you should be stocking more, not less.

North American Class 8 orders hit about 47,000 units in February 2026, up more than 150% year over year. June was even louder: orders rose 230% to roughly 31,400 units, the biggest jump of a seven-month streak. And retail sales? Up 3.9% in August to 18,575 units. That made three straight months of gains.

Read those two tracks side by side. Orders are exploding. Retail is creeping. What sits between them is factory capacity, and capacity is finite. Trucks ordered today get built months from now. The parts those trucks will need are being consumed right now, by trucks already on the road.

When new-truck production slots fill up, two things happen. Fleets wait longer for deliveries. And the trucks they planned to trade in keep running instead of sitting in a dealer's lot.

A 2012 Kenworth with 900,000 miles still needs brake hoses, even when its replacement is backordered. Every extra month it runs wears down bushings, lines, and fittings. The parts wear out on the old truck. The invoice goes to you, if you have the part.

Part of this year's order surge is borrowed, not earned. EPA 2027 emissions rules are pushing fleets to buy now instead of later. The classic pre-buy.. Orders placed early fill 2026 and early 2027 production. After a pre-buy peak comes a trough. It always does.

So don't build next quarter's stock plan on this quarter's order curve. Regulation bent that curve, not just freight demand. Stock for what the fleet on the road today will consume tomorrow. The average truck age in North America keeps climbing, and those trucks all wear out hoses.

Here is the decision worth making before your next PO. Two ways to stock:

• Way one: by part number. Last year's list, this year's order. Safe on paper. But when a model year changes, the part number changes with it. Did the hose change? Check the numbers: a hydraulic brake hose comes in three common sizes: 3.2 mm ID with a 10.5 mm OD and 3.65 mm wall; 4.8 mm ID with a 12.5 mm OD and 3.85 mm wall; 6.3 mm ID with a 15 mm OD and 3.65 mm wall. A model year rarely moves those. It moves the part number on the box.
• Way two: by bore size. Cover the three diameters, and a changed part number stops mattering. The shop asks for a hose for a truck; the truck takes a 4.8 mm line; you have 4.8 mm in three lengths. Phone call handled.

And here's the part nobody puts in a catalog: the stockout almost never happens in your most expensive line. It happens in the most common bore, usually 4.8 mm, the line that fits half the trucks rolling through independent shops. Your dead stock sits in the fancy sizes. Your lost sales sit in the boring one.

So what does a smarter reorder list look like? It depends on what your warehouse actually serves:

• Shops-first warehouse. Independent shops touch everything. Weight your stock toward 4.8 mm (roughly half your hydraulic hose SKUs), then 3.2 mm, then a slim 6.3 mm line. Keep three lengths per bore, not ten part numbers per bore.
• Small-fleet-first warehouse. Fleets run the same power units for years. Pull your top ten units from maintenance records, map their line sizes, and stock the two bores that cover them. Add 3.2 mm only for the light-duty calls you actually get.
• Mixed warehouse. Split the difference: 50% on 4.8 mm, 30% on 3.2 mm, 20% on 6.3 mm. Review every quarter against what shops actually asked for, including the calls you couldn't fill. The misses are your real demand data.

Ask for the spec sheet on all three bore sizes, a sample of any one diameter within 48 hours, and a mixed-container quote for your next quarter. One email: info@jzhose.com. Bring your top ten part numbers, and we'll map them to bore sizes with you.

Do record Class 8 truck orders really help aftermarket parts sales?

Yes, and the mechanism is counterintuitive. Order booms fill factory capacity, which delays retirements. Older trucks keep running. Brake hoses keep wearing out. Record orders and rising hose demand are not opposites. They show up together.

Why stock by bore size instead of part number?

Because part numbers change with model years and bore sizes usually don't. The three common hydraulic sizes (3.2, 4.8, and 6.3 mm) cover most brake line calls an independent shop makes. When a part number changes and the bore doesn't, a bore-first warehouse keeps selling while a part-number warehouse writes a special order.

What's the smallest mixed order I can start with?

Start with your own call log, not a catalog. Map last quarter's unanswered requests to bore sizes. Order the top two diameters as a mixed shipment. Add the third only when the calls justify it. Samples of any single diameter go out within 48 hours, so you can verify fit before committing a container.