Rexroth axial piston hydraulic pump for the O&K Antriebstechnik wheel loader 1101132 2161297 2245086 4530809 4531445 75254773 873023

O&K (Orenstein & Koppel), and later its successor lines under Terex and New Holland Construction branding, built wheel loaders that demanded consistent high-pressure hydraulic output for demolition, quarry, and heavy earthmoving work. Bosch Rexroth's axial piston pumps — particularly the A4VG, A10VG, and A11VO/A11VLO series — became the go-to choice because they offered:

Variable displacement control, letting the pump match output to load demand instead of running at fixed flow

High pressure tolerance (often 350–450 bar continuous, higher intermittently), suited to heavy lift arm and bucket cylinders

Compact packaging that fits O&K's engine bay and closed-loop hydrostatic drivetrain layouts

Serviceability, since Rexroth's modular design allows swapping control valves, shaft seals, and swash plate assemblies without replacing the entire unit

In short, Rexroth pumps gave O&K a component that could survive punishing duty cycles while still being field-serviceable — a combination that's hard to find elsewhere in the industrial hydraulics market.

Common Rexroth Pump Models Found in O&K Wheel Loaders

A4VG Series (Hydrostatic Drive Pumps)

Used primarily for propulsion in closed-loop systems. These pair with an A6VM or similar variable-displacement motor to form a complete hydrostatic transmission. Displacement typically ranges from 28 cc/rev to 180 cc/rev, depending on loader size class.

A10VO Series (Open-Circuit Work Pumps)

These handle the loader's implement functions — lift arm, bucket tilt, and auxiliary attachments. They're often mounted on a shared drive with the drive pump, forming a tandem pump arrangement that's common on mid-size O&K models like the L15 and L20 loader classes.

A11VO / A11VLO Series (High-Pressure Piston Pumps)

Found on larger O&K units where sustained high-pressure output is needed for heavier lift capacities and steering assist circuits.

Recognizing a Failing Axial Piston Pump

Symptom: Loss of Lift or Tilt Power

If the bucket lifts slowly under load, or the arm sags noticeably when holding a full bucket, the swash plate control or the pistons themselves may be worn, causing internal leakage (often described as "slip") that bleeds off pressure.

Symptom: Whining or Cavitation Noise

A high-pitched whine, especially on cold start, frequently points to air ingestion at the suction line or a worn charge pump — the small gear pump that pre-pressurizes fluid into the main piston pump's inlet.

Symptom: Overheating Hydraulic Fluid

Excess internal leakage converts hydraulic energy into heat. If your reservoir temperature climbs well above the typical 60–80°C operating range, worn piston shoes or a scored cylinder block barrel are common causes.

Symptom: Erratic Steering or Drift

In closed-loop drive applications, a failing charge relief valve or a sticking servo piston inside the A4VG can cause the machine to creep or drift even when the joystick is centered.

Maintenance Practices That Extend Pump Life

Fluid cleanliness is non-negotiable. Axial piston pumps run tight tolerances between piston and bore; contamination is the leading cause of premature wear. Target ISO cleanliness codes specified in the O&K service manual, typically 18/16/13 or better.

Change filters on schedule, not just on indicator lights. By the time a clog light triggers, abrasive particles have often already been circulating.

Warm up hydraulics before heavy work, especially in cold climates. Cold, viscous oil starves the charge pump and increases cavitation risk during the first minutes of operation.

Monitor case drain temperature and flow periodically rather than waiting for a symptom to appear — it's the earliest warning sign available.

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Q1: How long do Rexroth axial piston pumps typically last on a wheel loader?

A1: With clean fluid and regular maintenance, 8,000–12,000 operating hours before a rebuild is common. Contamination, cavitation, or running low on fluid dramatically shortens that lifespan.

Q2: Is it normal for a hydraulic pump to make noise when cold?

A2: A brief, quiet whine that disappears once the fluid warms up can be normal in cold climates. A persistent or worsening whine at any temperature usually indicates cavitation or a failing charge pump and should be inspected.

Q3:What is the price and delivery time of the Rexroth hydraulic pump for the O&K Antriebstechnik wheel loader？

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

Q4:How to purchase a Rexroth hydraulic pump for an O&K Antriebstechnik wheel loader?

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