What This Air Spring Is
This is a rolling-lobe air spring for a trailer axle, not a convoluted bellows. Design height is 13.5 in, roughly 21.6 in fully extended and about 7.9 in collapsed, and it carries around 7,160 lb at 100 psi. Those four numbers are what actually decide whether a bag belongs under a given hanger and axle seat.
The top plate is a 2-stud mount. The bottom is a 4-bolt composite piston with the bolt pattern set at 45 degrees. If your old bag has a steel piston or a different stud count on top, you are looking at a different assembly even if the height looks close. Check the plate before you order.
PartStop sells this as an aftermarket direct replacement. We are not affiliated with, endorsed by, or authorised by Goodyear, Firestone, Hendrickson or any other manufacturer named here. Their part numbers appear only so you can identify the bag you have in your hand.
Why These Numbers Cross
Air springs get built by a handful of bellows manufacturers and then re-boxed under suspension and dealer brands. That is why 1R12-092 from Goodyear and W01-358-9082 from Firestone describe the same physical bag: same 13.5 in design height, same 2-stud top, same 45-degree 4-bolt composite piston, same load rating at 100 psi.
The suspension builders then assign their own numbers to the bag they specify. Hendrickson calls it B2066. SAF-Holland lists 90557075. Ridewell uses 1003589082C. ContiTech carries it as 9 10-16 P 310. Dealer and private-label channels add AS90820 and AS-8310. Different boxes, same envelope and mounting hardware.
Because the numbers share dimensions and mounting geometry, one bag replaces any of them in the position it was originally fitted. That is identification, not a fitment promise. Confirm against the number moulded or stamped on the old bag, or against the trailer VIN and suspension tag, before you commit.
Before You Order
Pull the old bag and read it. The number is usually on the top plate or moulded into the bellows sidewall. If it's unreadable, measure ride height from the top plate face to the piston mounting surface with the suspension aired to normal ride, and count the studs on top and the bolts on the piston.
Replace bags in pairs across an axle. A new bag next to a fatigued one changes load sharing and will cook the new one. While the axle is unloaded, check the height control valve linkage, the shocks, and the air lines at the fitting — most repeat bag failures trace back to a valve holding the wrong height or a shock that stopped controlling travel.
1R12-092 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to 1R12-092. 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 |
|---|---|
| ContiTech | 9 10-16 P 310 |
| Firestone | W01-358-9082 |
| Hendrickson | B2066 |
| Ridewell | 1003589082C |
| SAF-Holland | 90557075 |
| TRP | AS90820 |
| Triangle | AS-8310 |
Frequently asked questions
Is 1R12-092 the same as W01-358-9082?
They describe the same rolling-lobe bag — 13.5 in design height, 2-stud top plate, 4-bolt 45-degree composite piston, roughly 7,160 lb at 100 psi. One is the Goodyear number, the other the Firestone number. Verify against the number on your old bag or your trailer VIN before ordering, since suspensions get modified in service.
How do I know if my air bag is bad or if it's the height control valve?
Air the system up and soap the bag, the top plate studs, and the fitting. A leaking bellows will bubble or you'll hear it. If the bag holds air but the trailer sits low or high, the height control valve or its linkage is the more likely cause. Check ride height against the suspension manufacturer's spec before you condemn the bag.
Do I have to replace both air springs on the axle?
Replace them in pairs. A new bag has different spring characteristics than one with years of heat cycles and flex in it, so the new one takes more of the load and fails early. If you're already under the trailer, doing both sides is cheap labour compared to a second road call.
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
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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.