Look at a used brake chamber and you may find several numbers on it: one cast into the housing, one on a sticker, one stamped by whoever last rebuilt it. They come from different places and they are not equally useful. Our catalogue holds numbers of all three kinds — 496 references across 52 brands — and the kind matters when you are deciding what to trust.
OEM — the vehicle manufacturer's number
The number the truck maker assigns to the part in its own parts system. Mercedes-Benz, MAN, Volvo, Scania, DAF, IVECO, Renault Trucks, Setra, Neoplan.
This is the most useful number you can have, because it is tied to a specific vehicle and a specific position on it. If you have the OEM number and it is the number for your vehicle, the fitment question is largely settled.
Two things to know about them:
They get superseded. Manufacturers replace numbers, sometimes several times over a model's life. A superseded number still identifies the part, but a catalogue may only list the current one.
Prefixes are part of the format, sometimes. Mercedes prints its genuine-part numbers with an A prefix — A000 431 1728 and 000 431 1728 are one number written two ways. We treat them as one part with one page; type either and you land in the same place.
OES — the brake system supplier's number
The company that actually manufactures the brake chamber for the vehicle maker has its own numbering. In air brakes that is WABCO, Knorr-Bremse and Haldex, and in North America Bendix.
An OES number is nearly as good as an OEM number, and sometimes better: one WABCO number can cover the same chamber fitted by several different truck makers. That is why a WABCO number often has the widest cross-reference list of any number for a given part — it is the number closest to the physical thing.
If you have both an OEM and an OES number, quote the OES one. It is less likely to have been superseded and more likely to be recognised by whoever you are buying from.
Aftermarket — a parts brand's own code
Sampa, Febi, Diesel Technic, PE Automotive, Auger, Corteco, Meyle and dozens more assign their own codes to the parts they sell. So do we: VF-30N is ours.
These numbers are real and useful for reordering from that brand. What they are not is a description of the original part. An aftermarket code tells you what one supplier decided to call their version. Two brands can catalogue slightly different parts under codes that both claim to replace the same OEM number.
This is why our own SKU is built to be read rather than looked up: VF-30N is Type 30, normal stroke. You can decode it without us.
Which to search with
In order of how much the answer is worth:
- OES number (WABCO, Knorr-Bremse, Haldex, Bendix) — closest to the physical part, widest coverage.
- OEM number (the truck maker's) — tied to your vehicle, but may be superseded.
- Another brand's aftermarket code — will usually get you there, but you are trusting that brand's cross-reference as well as ours.
- Type and stroke — not a number at all, and the most reliable of the four. Both are readable off the chamber.
All four work in our cross-reference tool. The fourth also works: type 24L or T30 instead of a number.
What none of them tell you
None of these numbers tell you whether the chamber in front of you still contains what its housing says it should. A chamber that was rebuilt with a different kit carries a number that no longer describes its contents — which is the reason every page here asks you to confirm Type and stroke against the part rather than trusting the lookup alone. That check, and why it is not boilerplate, is covered separately.
Send us any of the four and you will get an answer within 24 hours from a named person. If the number is one we do not hold, you will be told that instead of being offered the nearest match.