Restoring a BOMAG BW 124 D Single Drum Roller with Missing Hydraulic Components

[MikePhua]

The BOMAG BW 124 D and Its Role in Soil Compaction
The BOMAG BW 124 D is a mid-sized single drum vibratory roller designed for soil compaction in road construction, site preparation, and utility trench backfill. Manufactured by Compaction America in Kewanee, Illinois, this model was part of BOMAG’s push into the North American market during the late 1990s and early 2000s. With an operating weight of approximately 2,757 kg and powered by a Deutz diesel engine, the BW 124 D offered a balance of maneuverability and compaction force for small to medium-sized projects.
Its design includes a smooth steel drum with vibration capability, hydrostatic drive, and a hydraulic system that powers both propulsion and compaction. Like many BOMAG rollers, the BW 124 D uses a gear pump assembly to manage hydraulic flow—an essential component for drum vibration and travel functions.
Identifying the Machine and Serial Number Confusion
One challenge in restoring older BOMAG rollers is identifying the correct model and serial number. In this case, the machine was labeled as a “124 D” on the side decal, but the data plate listed it as a “BW 124 PDB.” This discrepancy is common in older units, where marketing names and production codes diverge.
The serial number provided—A219C2008V—is not the actual machine serial used for parts lookup. BOMAG serial numbers typically consist of 12 digits with no letters, starting with prefixes like 1015, 9015, or 8615. Without the correct serial, sourcing parts becomes difficult, especially for hydraulic components.
Missing Hydraulic Gear Pump and Part Identification
The most pressing issue with this roller was the absence of the double gear pump, part number 0935713. This pump is responsible for generating hydraulic pressure for both drive and vibration circuits. Without it, the machine cannot move or compact.
Gear pumps in BOMAG rollers are typically mounted directly to the engine or transmission housing and feature dual output sections. These pumps are precision-machined and matched to the flow requirements of the system. Replacing them requires:

• Verifying the pump’s displacement and pressure rating
  
• Matching the flange and shaft type to the engine interface
  
• Ensuring compatibility with the hydraulic control valves
  
• Confirming the direction of rotation (clockwise or counterclockwise)
  

In the absence of the original pump, suppliers often request photos or measurements to identify a suitable replacement. This can be frustrating, but it’s necessary due to the wide variation in pump configurations across models and years.
Sourcing Parts and Navigating the Aftermarket
Finding a replacement pump for a BOMAG BW 124 D can be challenging. BOMAG’s parts network is robust, but older models may be out of production. Options include:

• Contacting BOMAG directly with the correct serial number
  
• Working with hydraulic specialists who can cross-reference pump specs
  
• Searching salvage yards or auction sites for donor machines
  
• Using aftermarket pump manufacturers like Permco, Parker, or Casappa
  

Some operators have had success sourcing parts from European suppliers, especially for BOMAG units originally built for export. However, shipping costs and compatibility risks must be considered.
Engine and Hydraulic System Integration
The Deutz engine powering the BW 124 D is known for reliability and fuel efficiency. It typically uses a mechanical governor and direct injection. When integrating a new hydraulic pump, care must be taken to:

• Align the pump shaft with the engine coupler
  
• Use proper mounting bolts and torque specs
  
• Prime the hydraulic system to prevent cavitation
  
• Flush old fluid and replace filters to avoid contamination
  

Hydraulic systems on BOMAG rollers are sensitive to debris and air pockets. After installing a new pump, technicians should bleed the system thoroughly and monitor pressure readings during startup.
Lessons from Field Repairs and Auctions
This particular roller was purchased from an equipment auction, a common source for affordable machines with unknown histories. Auctions can yield bargains, but they also carry risks—missing parts, undocumented repairs, and mismatched decals are frequent issues.
One operator shared that he bought a similar BOMAG roller with a seized drum bearing. After sourcing parts from a donor machine and rebuilding the bearing housing, the roller performed flawlessly for years. The key was patience, documentation, and a willingness to fabricate brackets and hoses when OEM parts weren’t available.
Conclusion
Restoring a BOMAG BW 124 D single drum roller with a missing hydraulic gear pump is a complex but achievable task. Success depends on accurate model identification, careful sourcing of hydraulic components, and methodical integration with the engine and control systems. While older rollers may lack the polish of newer models, their mechanical simplicity and rugged design make them ideal candidates for rebuilds. With the right approach, even an auction-sourced machine can return to the jobsite and deliver reliable compaction for years to come.