The Bomag 05815991 Back-Up Ring is a genuine OEM component designed for Bomag single drum rollers and tandem rollers across a wide range of BW-series and C-series models. Sourced directly from Bomag, this back-up ring delivers the exact material grade, dimensional tolerance, and cross-section profile required by the original hydraulic or pneumatic sealing circuit it serves. Compatible models include the BW 211, BW 212, BW 213, BW 172, BW 142, BW 145, BW 178, and BW 214 single drum roller lines, the BW 161 and BW 202 tandem rollers, and the C 825 C and C 850 C single drum rollers — making this a widely applicable seal component across Bomag's heavy roller fleet. Using genuine OEM part number 05815991 ensures you are installing the correct ring the first time, with no risk of premature seal failure from mismatched geometry.
Key Features
- Genuine OEM Seal Material — manufactured to Bomag's original compound and hardness specifications, ensuring the back-up ring maintains its anti-extrusion function under rated hydraulic pressure without distortion or cracking
- Exact Cross-Section Fit — matches the original groove geometry in the host bore or piston assembly, allowing this ring to seat correctly alongside the primary seal without shimming or rework
- Broad BW-Series and C-Series Coverage — fits BW 211, BW 212, BW 213, BW 172, BW 142, BW 145, BW 178, and BW 214 single drum rollers, BW 161 and BW 202 tandem rollers, and C 825 C and C 850 C single drum rollers, among others
- Prevents Seal Extrusion and Fluid Loss — a correctly functioning back-up ring stops the primary seal from extruding into the clearance gap under pressure, protecting against hydraulic fluid bypass and internal leakage
- Direct OEM Traceability — part number 05815991 is the authoritative Bomag reference, making it straightforward to verify against service manuals and parts books during scheduled maintenance or field repair
A back-up ring is a rigid or semi-rigid sealing support ring installed on one or both sides of a primary O-ring or lip seal in a hydraulic cylinder or rotary circuit. Its job is to prevent the softer primary seal from being forced into the metal clearance gap between mating components when system pressure rises — a failure mode known as extrusion. When a back-up ring wears, hardens, or is omitted during a rebuild, the primary seal extrudes and quickly fails, leading to hydraulic fluid loss, loss of cylinder or motor pressure, and potential damage to the surrounding bore. Replacing this component with the correct genuine OEM part at each seal service interval is essential for maintaining hydraulic integrity across the compaction and propulsion systems on these rollers.
Part Details
| Part Number | 05815991 |
|---|---|
| Brand | Bomag |
| Part Type | Genuine OEM |
| Description | Back-Up Ring |
Compatibility & Fitment
| Name | Model | Machine Number |
|---|---|---|
| Single Drum Roller | BW 211 DE-40 | 00800913, 00818741 |
| Single Drum Roller | BW 172 D-2 | 00810074 |
| Single Drum Roller | BW 142 D-2 | 00810077 |
| Single Drum Roller | BW 213 D-3 | 00815320, 00815390, 00817522, 00817523, 00817588 |
| Single Drum Roller | BW 212 D-3 | 00815325, 00815326 |
| Single Drum Roller | BW 178 D-3 | 00815515 |
| Single Drum Roller | BW 145 DH-3 | 00817481, 00817638 |
| Single Drum Roller | BW 145 PDH-3 | 00817483, 00817639 |
| Tandem Roller | BW 161 AC-2 | 00817492 |
| Tandem Roller | BW 161 AD-2 | 00817493, 00817494 |
| Tandem Roller | BW 202 AD-2 | 00817516, 00817517 |
| Tandem Roller | BW 202 AHD-2 | 00817518 |
| Single Drum Roller | BW211D 3 | 00817520, 00817581, 00817649 |
| Single Drum Roller | BW212D 3 | 00817521 |
| Single Drum Roller | BW145PDH 3 | 00817577 |
| Single Drum Roller | C 825 C | 00817578 |
| Single Drum Roller | C 850 C | 00817583 |
| Single Drum Roller | BW 211 PD-3 | 00817608 |
| Single Drum Roller | BW 211-PD-3 | 00817651 |
| Single Drum Roller | BW 211 D-4 | 00817771, 00817951, 00818127, 00824159, 00824389 |
| Single Drum Roller | BW 213 D-4 | 00817773, 00818293, 00824157, 00824387 |
| Single Drum Roller | BW 212 D-30 | 00817907 |
| Single Drum Roller | BW 145-DH-3 | 00817929 |
| Single Drum Roller | BW 211 PD-4 | 00817939, 00818329, 00824161, 00824391 |
| Single Drum Roller | BW 211 D-40 | 00817941, 00818129, 00818371, 00818391, 00818875, 00824269 |
| Single Drum Roller | BW 212 D-40 | 00817943, 00818587, 00818823, 00818881, 00824279 |
| Single Drum Roller | BW 213 D-40 | 00817945, 00818291 |
| Single Drum Roller | BW 212 PD-40 | 00818061, 00818883 |
| Single Drum Roller | BW 213 PD-40 | 00818063 |
| Single Drum Roller | BW 211 PD-40 | 00818065, 00818319 |
| Single Drum Roller | BW 213 PD-4 | 00818167, 00818335 |
| Single Drum Roller | BW 145 DH 40 BW 145 DH 4 | 00818325 |
| Single Drum Roller | BW 145 PDH 40 BW145 PDH 4 | 00818327 |
| Single Drum Roller | BW211D 40 | 00818415 |
| Single Drum Roller | BW211PD 40 | 00818417 |
| Single Drum Roller | C850D | 00818433 |
| Single Drum Roller | BW 214 D-4 | 00818651, 00824185 |
| Single Drum Roller | BW 211 D-50 | 00818869 |
| Single Drum Roller | BW145DH 40 | 00818939, 00818941 |
| Single Drum Roller | BW145PDH 40 | 00818943 |
| Single Drum Roller | BW 211 PD-50 | 00824195 |
| Single Drum Roller | BW 212 D-40 BR | 00824413, 00824785 |
| Single Drum Roller | BW 211 D-4 EU-Flex | 00824429 |
| Single Drum Roller | BW 213 D-4 EU-Flex | 00824431 |
| Single Drum Roller | BW 211 D-4i | 00824437 |
Verify Before You Order
Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.
Why Buy From DHS Equipment
Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.
Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.
