The Bomag 05553666 Reducing Union is a genuine OEM component designed for Bomag tandem rollers across the BW 154, BW 170, BW 174, BW 100, BW 120, BW 135, and BW 138 series, including models BW 154 AP-4 AM, BW 154 AP-4, BW 154 ACP-4 AM, BW 154 ACP-4, BW 170 AP AM, BW 174 AP. Sourced directly from Bomag, this reducing union meets the exact specifications of the original part it replaces. This genuine OEM part ensures a correct, leak-free connection within the hydraulic or fluid circuit — maintaining system pressure and flow exactly as Bomag engineered it. If you are servicing a covered tandem roller, ordering by part number 05553666 confirms you are getting the right fitting for the application.
Key Features
- Genuine OEM Fluid-Line Integrity — manufactured to Bomag's exact thread form and material specification, ensuring a secure, leak-free seal in the hydraulic or fluid circuit rather than a compromised fit from a mismatched fitting
- Direct-Fit Replacement — this reducing union installs directly into the existing port without rework, matching the original thread sizes and union geometry found on the production machine
- Broad Tandem Roller Coverage — fits a wide range of Bomag tandem rollers including the BW 154 AP-4, BW 154 ACP-4, BW 174 AP-4, BW 174 ACP, BW 100 AD-5, BW 120 AD-5, BW 120 SL-5, BW 138 AD-5, BW 135 AD-5, and related variants
- System Pressure Protection — a correctly fitted reducing union maintains proper fluid routing between different line sizes; a cracked, cross-threaded, or undersized union can cause pressure loss, fluid leaks, and component damage downstream
- Fluid-System Safety — hydraulic fluid leaks at union connections present a fire and slip hazard on an operating machine; an OEM-spec union at part number 05553666 eliminates the failure modes associated with poorly fitting replacements
A reducing union is a threaded fitting that connects two fluid lines of different diameters, allowing hydraulic or cooling fluid to transition between line sizes without loss of pressure or flow efficiency. In Bomag tandem rollers, these fittings are used throughout the hydraulic and ancillary fluid circuits to route fluid between pumps, motors, valves, and coolers. When a reducing union cracks, strips, or begins to weep fluid, the affected circuit loses pressure, leading to sluggish drum drive response, erratic vibration control, or overheating — all of which interrupt compaction performance and can escalate into more costly repairs if left unaddressed.
Part Details
| Part Number | 05553666 |
|---|---|
| Brand | Bomag |
| Part Type | Genuine OEM |
| Description | Reducing Union |
Compatibility & Fitment
| Name | Model | Machine Number |
|---|---|---|
| Tandem Roller | BW 154 AP-4 AM | 00818299, 00824177, 00824715 |
| Tandem Roller | BW 154 AP-4 | 00818301, 00824179, 00824717 |
| Tandem Roller | BW 154 ACP-4 AM | 00818303, 00824719 |
| Tandem Roller | BW 154 ACP-4 | 00818305, 00824721 |
| Tandem Roller | BW 170 AP AM | 00818515 |
| Tandem Roller | BW 174 AP | 00818517 |
| Tandem Roller | BW 174 ACP | 00818519 |
| Tandem Roller | BW 174 ACP-AM | 00818535 |
| Tandem Roller | BW 174 AP-AM | 00818537 |
| Tandem Roller | BW 174 AP-4 AM | 00818655, 00818845, 00824543 |
| Tandem Roller | BW 174 AP-4 | 00818657, 00818847, 00824545 |
| Tandem Roller | BW 174 AP-4 AM PB | 00818971 |
| Tandem Roller | BW 174 AP-4 PB | 00818973 |
| Tandem Roller | BW 100 AD-5 | 00824833, 00824995, 00825357, 00825643, 00826215, 00826219, 00827043 |
| Tandem Roller | BW 120 AD-5 | 00824835, 00824997, 00825359, 00825645, 00826049, 00826217, 00826221, 00827045 |
| Tandem Roller | BW 100 AC-5 | 00824837, 00825361, 00826091, 00827047 |
| Tandem Roller | BW 120 AC-5 | 00824839, 00825363, 00826093, 00827049 |
| Tandem Roller | BW 138 AD-5 | 00824927, 00825351 |
| Tandem Roller | BW 138 AC-5 | 00824929 |
| Tandem Roller | BW 135 AD-5 | 00824931, 00825355 |
| Tandem Roller | BW 100 SL-5 | 00824999, 00826553 |
| Tandem Roller | BW 120 SL-5 | 00825001, 00825615, 00827055 |
| Tandem Roller | BW 120 SLC-5 | 00826435 |
| Tandem Roller | BW 120SL-5 | 00826609 |
| Tandem Roller | BW 120 AD-5 CC | 00826793 |
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.
