Rexroth A4VG A4VTG variable hydraulic pump for CNH Engineering equipment 2185793 4530337 4531321 6557459 6559082 87269803 87634754

The A4VG and A4VTG are swashplate-type axial piston pumps manufactured by Bosch Rexroth, a German engineering firm that has become the de facto standard for closed-circuit hydrostatic transmissions in construction and agricultural machinery. Both pumps use a rotating cylinder block with pistons arranged around a central shaft; as the block spins, the pistons stroke in and out against an angled swashplate, drawing in and expelling hydraulic fluid.

Why CNH Equipment Relies on This Pump Family

Case and New Holland Construction share engineering platforms across much of their excavator, crawler dozer, and wheel loader lineups, and closed-loop hydrostatic drives are the backbone of that platform strategy. A few reasons this pump family keeps showing up on the parts list:

Precision travel control. Operators need fine, proportional control over ground speed, especially during fine grading or when creeping a load up a slope. The infinitely variable displacement of the A4VG/A4VTG gives smooth modulation that a fixed-displacement gear pump simply can't match.

Efficiency under variable load. Because displacement adjusts to match demand rather than running wide open all the time, these pumps reduce parasitic hydraulic losses, which translates into better fuel economy — a selling point CNH markets heavily on newer Case and New Holland models.

Compact, integrated packaging. The tandem A4VTG design saves space in tight undercarriage compartments compared to running two independent pumps, which matters on smaller excavator classes where engine bay real estate is limited.

Proven reliability at scale. Bosch Rexroth's global service and parts network means CNH dealers can source rebuild kits, seal kits, and control valves without long lead times — a practical consideration for fleet managers who can't afford a machine sitting idle for weeks.

Where You'll Find It on the Machine

On a typical CNH crawler excavator, the A4VTG mounts directly to the engine flywheel housing, driven off the engine's power take-off. Two independent hydraulic circuits run from the pump to the left and right travel motors, each modulated by its own control piston and servo system. Wheel loaders and some crawler dozers use a similar arrangement, sometimes combining a single A4VG for propulsion with separate gear pumps handling implement and steering circuits.

Key Components Inside the Pump

Rotating group — cylinder block, pistons, and valve plate that handle the actual fluid displacement

Swashplate and servo piston — controls displacement angle in response to hydraulic or electronic control signals

Charge pump — a smaller fixed-displacement gear pump mounted on the back of the unit that keeps the closed loop topped off and replaces fluid lost to internal leakage

DA (electric proportional) or HW (hydraulic) control — the interface that tells the swashplate how far to stroke, based on either an electric signal from the machine's ECU or a hydraulic pilot pressure from the joystick circuit

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Q1: How long do these pumps typically last on a CNH machine?

A1: With clean fluid and regular filter changes, it's common to see these pumps run several thousand hours before needing internal service, though heavy-duty applications with poor fluid maintenance can see failures much sooner.

Q2: Does a failing charge pump always mean the whole unit needs replacing?

A2: No. The charge pump is a separate, smaller gear pump bolted to the back of the main unit, and it can often be replaced on its own without touching the main rotating group.

Q3: What is the price and delivery time of the A4VG/A4VTG hydraulic pump for the CNH Engineering equipment?

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

Q4: How to purchase an A4VG/A4VTG hydraulic pump for the CNH Engineering equipment?

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