What This Air Spring Is
This is a rolling-lobe, or reversible-sleeve, trailer air spring. The bellows rolls over a composite-style piston instead of folding like a convoluted bag. Extended height is 15.8 in, compressed height is 5.4 in, and the bellows runs roughly 9.75 in diameter. The top is a stud bead plate, the bottom mounts to the piston. Position is trailer axle.
It carries the trailer on the Hendrickson HT-190T and HS-190T air suspension. The bag holds ride height, the leveling valve feeds it, and the shock controls it. When the bag goes soft or blows, ride height drops, the axle sits on the stops, and cargo takes the hit through the floor.
The PartStop unit is an aftermarket direct replacement built by Zhuhai Fengli. It is not an OEM part and we are not affiliated with Firestone, Hendrickson, or any other manufacturer listed here. Their numbers appear for identification only, so you can match what is bolted to your trailer today.
Why These Numbers Cross
Air spring numbering is fragmented because the bag is sold by the bellows maker, by the suspension maker, and by the distributor, all under different systems. W01-358-9640 is the Firestone-style number. S-20223 is how Hendrickson catalogs the same bag as a suspension service part. Goodyear lists 1R12-367 and 566-24-3-076. ContiTech uses 64395 and 910-12A427.
Triangle 8427, Torque TR9640, and Neway G2299640400 land in the same group. They all describe a reversible-sleeve bag with the same extended and compressed heights, the same bellows diameter, and the same stud bead-plate top with piston bottom. Same envelope, same mounting pattern, same job on the axle.
Cross-reference is a starting point, not a fitment promise. HT-190T saw a number of versions over its production life, and mounting hardware and ride height specs vary between builds. Confirm against the number stamped or tagged on the bag you are pulling off, or against the trailer VIN, before you order.
Checks Before You Order
Air the trailer up and walk it. Soap the bead plate seam, the piston crimp, and the air fitting. A bag that leaks at the crimp is done. A bag that leaks only at the fitting may just need the port cleaned and resealed. Chafe marks on the sidewall mean something is rubbing and will kill the new bag too.
Measure ride height at the axle before you tear into it, and check the leveling valve linkage. A bent or worn linkage rod will set the wrong height and overwork the bags. Replace bags in pairs across an axle so the trailer sits level and load splits evenly, and check the shocks while the wheels are off the ground.
W01-358-9640 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to W01-358-9640. 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 | 64395, 910-12A427 |
| Goodyear | 1R12-367, 566-24-3-076 |
| Hendrickson | S-20223 |
| Neway | G2299640400 |
| Torque | TR9640 |
| Triangle | 8427 |
Frequently asked questions
Is S-20223 the same bag as W01-358-9640?
They cross to the same reversible-sleeve trailer air spring. S-20223 is the Hendrickson suspension service number, W01-358-9640 is the Firestone-style number for the same bellows and mounting configuration. Verify against the tag on your old bag, since HT-190T ran in several versions.
What ride height should this bag set on an HT-190T?
Ride height is set by the suspension and the leveling valve, not the bag. Use the ride height spec for your specific HT-190T or HS-190T build, then adjust the leveling valve linkage to hit it. This spring measures 15.8 in extended and 5.4 in compressed, which is the working range you have to stay inside.
Do I have to replace both air springs on the axle?
Do the pair. A new bag next to an old bag will sit at a slightly different height and load, and the older one is usually not far behind. Replacing both keeps the trailer level and stops chasing a second failure a few thousand miles later.
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.