20/925580 JCB Hydraulic Gear Pump | 36+29cc 250 bar for 3CX/4CX

Product Overview

The 20/925580, 20/925579, and 332/F9028 are heavy-duty twin hydraulic gear pumps manufactured by Parker Hannifin for JCB 3CX / 3DX / 4CX series backhoe loaders. These models feature a twin gear pump (double gear pump) configuration, with two pump stages driven by a common input shaft, enabling simultaneous oil supply to two independent hydraulic circuits—serving the loader and excavator functions respectively.

Manufactured by Parker Hannifin to JCB original technical specifications, these pumps feature a high-strength cast iron housing with precision-machined gears and SAE standard interfaces, delivering excellent fatigue strength and dimensional stability. Engineered as a direct OEM-replacement solution, these models fully comply with JCB / Parker original design standards and mounting interface specifications, offering 100% direct interchangeability with OEM pumps. Every unit undergoes 100% workload simulation testing prior to shipment, rigorously validating pressure retention, volumetric efficiency, and internal leakage performance to meet or exceed OEM standards.

Model Cross-Reference:

• 20/925580 — Twin gear pump, front 36 cc/rev + rear 29 cc/rev

  • Cross references: 332/F9030, 7029120048, 4070H

• 20/925579 — Twin gear pump, front 36 cc/rev + rear 26 cc/rev

  • Cross references: 332/F9029, 20/925339

• 332/F9028 — Twin gear pump, front 33 cc/rev + rear 23 cc/rev

  • Cross references: 20/925578, 20/925586

Technical Specifications 

20/925580 Specifications

• Model: 20/925580 (JCB Part Number)

• Cross References: 332/F9030, 7029120048, 4070H

• Pump Type: Twin Gear Pump

• Front Pump Displacement: 36 cc/rev (36 L/min @ 1000 rpm)

• Rear Pump Displacement: 29 cc/rev (29 L/min @ 1000 rpm)

• Rotation: Clockwise (viewed from shaft end)

• Mounting Flange: SAE B 2-bolt flange

• Shaft: 1-inch diameter, 15-tooth SAE splined shaft, 16/32 pitch

• Maximum Working Pressure (Front Pump): 250 bar

• Maximum Working Pressure (Rear Pump): 275 bar

• Weight: Approx. 26 kg

• Housing Material: High-strength cast iron

• Compatible Models: JCB 3CX, JCB 4CX backhoe loaders

20/925579 Specifications

• Model: 20/925579 (JCB Part Number)

• Cross References: 332/F9029, 20/925339, 20/925338

• Pump Type: Twin Gear Pump

• Front Pump Displacement: 36 cc/rev (36 L/min @ 1000 rpm)

• Rear Pump Displacement: 26 cc/rev (26 L/min @ 1000 rpm)

• Rotation: Clockwise (viewed from shaft end)

• Mounting Flange: SAE B 2-bolt flange

• Shaft: 1-inch diameter, 15-tooth SAE splined shaft, 16/32 pitch

• Inlet: Single 2-inch SAE flange

• Front Pump Outlet: 1 1/16″-12 UNF threaded

• Rear Pump Outlet: 7/8″-14 UNF threaded

• Maximum Working Pressure (Front Pump): 250 bar

• Maximum Working Pressure (Rear Pump): 275 bar

• Maximum Input Shaft Torque: 460 Nm

• Weight: Approx. 26 kg

• Housing Material: High-strength cast iron

• Compatible Models: JCB 3CX, JCB 4CX, JCB 214E, JCB 3C series

332/F9028 Specifications

• Model: 332/F9028 (JCB Part Number)

• Cross References: 20/925578, 20/925586

• Pump Type: Twin Gear Pump

• Front Pump Displacement: 33 cc/rev (33 L/min @ 1000 rpm)

• Rear Pump Displacement: 23 cc/rev (23 L/min @ 1000 rpm)

• Rotation: Clockwise (viewed from shaft end)

• Mounting Flange: SAE B 2-bolt flange

• Shaft: 1-inch diameter, 15-tooth SAE splined shaft, 16/32 pitch

• Inlet: Single 2-inch SAE flange

• Front Pump Outlet: 1 1/16″-12 UNF threaded

• Rear Pump Outlet: 7/8″-14 UNF threaded

• Maximum Working Pressure (Front Pump): 275 bar

• Maximum Working Pressure (Rear Pump): 275 bar

• Maximum Input Shaft Torque: 460 Nm

• Weight: Approx. 26 kg

• Housing Material: High-strength cast iron

• Compatible Models: JCB 3CX, JCB 3DX, JCB 4CX

Key Technical Advantages

1. Twin Pump Design – One Pump, Two Circuits
These models feature a twin gear pump configuration with two stages driven by a common input shaft, enabling independent oil supply to both the loader and excavator hydraulic systems of the backhoe loader. This design significantly reduces the number of pumps required, saves installation space, and lowers system complexity. The two stages can operate independently or be combined for greater total flow output.

2. High-Strength Cast Iron Housing for Durability
The pump housing is manufactured from high-strength cast iron, offering superior fatigue strength and impact resistance compared to aluminum housings. The excellent damping characteristics of cast iron effectively absorb vibration and shock loads during operation—particularly suitable for backhoe loaders operating in harsh conditions over extended periods.

3. Optimized Gear Design with High Volumetric Efficiency
Precision-machined gears with optimized tooth profiles deliver stable hydraulic oil flow output and high volumetric efficiency. Low-noise, low-pulsation operation improves operator working conditions and reduces vibration fatigue risk in system piping.

4. High-Pressure Capability for Heavy-Duty Applications
Front pump maximum working pressure reaches 250–275 bar, rear pump up to 275 bar—fully meeting the high-pressure demands of backhoe loader operations including digging, lifting, and loading. Maximum input shaft torque of 460 Nm ensures reliable power transmission under extreme loads.

5. JCB OEM Specification – 100% Direct Interchangeability
All models are manufactured to JCB / Parker original technical specifications, with flange dimensions, spline shaft specifications, and mounting interfaces identical to OEM pumps. 20/925580 is cross-compatible with 332/F9030, 20/925579 with 332/F9029, and 332/F9028 with 20/925578—direct drop-in replacement with zero modifications required.

6. 100% Factory Tested
Every unit undergoes 100% workload simulation testing prior to shipment, covering pressure retention verification, internal leakage detection, and flow validation—ensuring every unit meets design performance standards.

Application Areas

This series of twin gear pumps is specifically designed for JCB backhoe loader hydraulic systems and is widely used in the following equipment:

• JCB 3CX Backhoe Loaders: 3CX, 3CX Super, 3CX LWT, 3CXS, 3CX-T and all series variants

• JCB 3DX Backhoe Loaders: 3DX Super, 3DX XTRA and variants

• JCB 4CX Backhoe Loaders: 4CX, 4CX Super, 4CXSM and variants

• JCB 214E / 3C Series: 214E, 3C, 3C 14 and variants

• Other JCB Equipment: JCB RTFL 926, RTFL 930, RTFL 940 telescopic handlers

Expert Maintenance Tips

1. Model Confirmation
20/925580, 20/925579, and 332/F9028 may appear similar but feature different displacement configurations. Before installation, always verify the complete part number on the original pump nameplate and confirm the correct model based on the machine serial number.

2. Rotation Direction Confirmation
All models feature clockwise rotation (viewed from the shaft end). Before installation, always verify that the PTO rotation direction of the host machine matches the pump’s rotation direction—incorrect rotation will result in pump failure to prime and may cause severe damage to gears and bearings within a short period.

3. Installation Precautions

• Thoroughly clean the SAE B 2-bolt flange and 1-inch 15-tooth SAE splined shaft mating surfaces before installation to ensure no debris remains

• Use SAE-specified torque values for mounting bolts—avoid over-tightening which may cause cast iron housing distortion or bolt fracture

• The inlet is a single 2-inch SAE flange; the two outlets are 1 1/16″-12 UNF and 7/8″-14 UNF threaded—ensure correct thread specifications during connection

4. First Start-Up and Bleeding

• Before first start-up, must fill both pump stages with hydraulic oil through the inlet port—never start dry

• After start-up, run at low speed with no load for 2–3 minutes to ensure complete air evacuation from both stages and the system

• Check both stages separately for abnormal noise or leakage

5. Fluid and Filtration

• Use high-quality anti-wear hydraulic oil compliant with JCB specifications

• Maintain system oil cleanliness to ISO 4406 18/15 or better

• Cast iron gear pumps are sensitive to fluid cleanliness—regularly replace return line filters

6. Periodic Maintenance

• Check mounting bolt torque every 1,000 operating hours

• Regularly monitor operating pressure of both stages—front pump not to exceed 250 bar (20/925580, 20/925579) / 275 bar (332/F9028), rear pump not to exceed 275 bar

• If flow output decreases, noise levels increase abnormally, or system temperature rises excessively, inspect and replace worn components promptly