Rexroth A10VO A10VG hydraulic pumps for Bomag Roller 05800989 5804420 5800944 5800928 05802506 05800992 05802020

Both the A10VO and A10VG are derived from Bosch Rexroth’s A10V series of swashplate-design axial piston units—a design that has served as the industry standard in construction and compaction machinery for decades, thanks to its compact structure, high energy efficiency, and repairability.

A10VO: The Open-Circuit Pump

The A10VO is an open-circuit variable displacement pump. It draws oil from a reservoir/tank, pushes it through the system, and returns it to the same tank. On a Bomag roller, this is typically the pump feeding functions like:

The vibration system (exciter drive)

Steering assist circuits

Auxiliary implement functions (water spray pumps, fan drives, etc.)

Because it's open-circuit, an A10VO is generally easier to diagnose from the outside — you can trace suction and return lines back to a single tank rather than a closed loop.

A10VG: The Closed-Circuit Propel Pump

The A10VG is a closed-circuit variable displacement pump, almost always paired with a hydraulic motor to form a hydrostatic drive train. On Bomag rollers, this is the propel pump — the unit that drives the roller forward and backward. Oil flows from the pump to the drive motor and back to the pump directly, with only a small charge pump topping off losses, rather than returning to the main tank.

This closed-loop design is what gives rollers their smooth, precise, and reversible travel control — critical for compaction work where operators are constantly changing direction and speed.

Bottom line distinction: if the pump in question drives the wheels or drums forward and backward, it's almost certainly an A10VG. If it powers vibration, steering, or an auxiliary circuit, it's more likely an A10VO.

Where These Pumps Fit on a Bomag Roller

Bomag single-drum and tandem rollers (common examples include the BW 120, BW 138, BW 177, BW 213, and BW 219 series, among others) use a hydrostatic transmission architecture, meaning nearly every major function — travel, vibration, steering — is hydraulically driven rather than mechanically linked.

Propel Circuit (A10VG)

The engine drives the A10VG pump directly off the flywheel housing or a splitter gearbox. The pump's swash plate angle, controlled electronically or hydraulically, determines flow direction and volume to the travel motors — which is how the operator gets variable speed and smooth direction changes from a single joystick or lever.

Vibration and Auxiliary Circuits (A10VO)

A separate A10VO pump (sometimes two, on larger machines) powers the vibration exciter motor inside the drum, along with secondary functions. Because vibration amplitude and frequency directly affect compaction quality, this pump's condition has a direct line to job-site output — a weak pump means weak compaction, even if the engine and drum look fine.

Tandem Rollers and Dual-Drum Setups

On tandem rollers (compacting with front and rear drums), it's common to see multiple A10VO/A10VG units working together — one managing propel for both drums via a shared hydrostatic circuit, and one or two more dedicated to vibration on each drum independently.

Maintenance Practices That Extend Pump Life

1. Oil cleanliness is non-negotiable. Axial piston pumps run tight internal tolerances; contamination is the single biggest killer of these units. Follow Bomag's specified filtration micron rating and change intervals.

2. Monitor case drain temperature and flow, not just system pressure. Rising case drain flow over time is often the earliest warning sign of internal wear, well before performance visibly drops.

3. Avoid prolonged high-load stalling, especially on the propel pump — repeatedly working a closed-loop system against a stalled load accelerates wear on pistons and the swash plate.

4. Check charge pressure regularly on the A10VG. Low charge pressure starves the main pistons of lubrication and can cause cavitation damage that's expensive to fix.

5. Don't ignore small leaks. A slowly weeping shaft seal is cheap to fix now and expensive to ignore later, once it progresses to internal contamination or bearing failure.

For more brand and equipment models, please visit https://www.baolilaihydraulic.com/brand/

Q1: Can I replace a Cat-branded pump with a standard Bosch Rexroth A10VO?

A1: Yes, but you must match the exact model code. Caterpillar often uses proprietary shafts, mounting flanges, or specific control valve calibrations. Always verify the full Rexroth part number (e.g., A10VO71DFR1/31R-VSC12K01) or the Cat OEM part number before swapping.

Q2: What causes an A10VO pump to lose pressure?

A2: The most common causes include a misadjusted or worn DFR/DR control valve, worn piston seals, scoring on the valve plate, or internal bypass due to excessive mechanical wear from contaminated oil.

Q3:What is the price and delivery time of the A10VO A10VG hydraulic pump for the Bomag Roller？

A3: The specific price and delivery time will depend on the equipment model or specific product model you provide.

Q4: How to purchase an A10VO A10VG hydraulic pump for a Bomag Roller?

A4:You can visit https://www.baolilaihydraulic.com/contact/ to contact us and purchase our products through various methods.