Product Overview
The Parker Hannifin 20/925580, 20/925579, and 332/F9028 series are OEM-specification tandem (dual-section) hydraulic gear pumps engineered specifically for JCB 3CX, 4CX, and other backhoe loader models. As the heart of the hydraulic system, these pumps deliver reliable pressure oil flow for loader, backhoe, steering, and auxiliary functions.
This series offers three displacement configurations — 36+29 cc/rev (20/925580 / 332/F9030) , 36+26 cc/rev (20/925579 / 332/F9029) , and 33+23 cc/rev (332/F9028) — comprehensively covering JCB backhoe loader models across different power ratings (82 HP, 92 HP, 100 HP) and hydraulic system configurations. All three models feature clockwise rotation (viewed from shaft end) and share identical SAE B 2-bolt flange mounting and 1″ 15-tooth SAE splined shaft specifications.
As direct OEM replacement solutions, these products are manufactured to strict Parker technical standards, ensuring 100% interchangeability with original equipment. Every unit undergoes 100% simulated duty-cycle testing to validate volumetric efficiency, thermal performance, and seal integrity under rated load conditions — guaranteeing reliable operation in heavy-load, high-dust, and high-temperature environments.
Technical Specifications
20/925580 (Parker Cross-Reference 332/F9030) – 36 + 29 cc/rev Configuration
Model: 20/925580 (JCB OEM Part No.) / 332/F9030 (Parker Cross-Reference)
Pump Type: Tandem (dual-section) 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)
Drive Shaft: 1″ diameter, 15-tooth SAE splined shaft, 16/32 pitch
Mounting Flange: SAE B, 2-bolt flange
Inlet Port: Single 2″ SAE flange inlet
Front Pump Outlet: 1 1/16″-12 UNF threaded
Rear Pump Outlet: 7/8″-14 UNF threaded
Front Pump Max. Working Pressure: 250 bar
Rear Pump Max. Working Pressure: 275 bar
Max. Input Shaft Torque: 460 Nm
Weight: 26 kg
Power Rating: 92 HP / 100 HP builds
Compatible Models: JCB 3CX, 3CX-T, 3CXS, 3CXS-PC, 4CX, 4CXM, 4CX-PC
20/925579 (Parker Cross-Reference 332/F9029) – 36 + 26 cc/rev Configuration
Model: 20/925579 (JCB OEM Part No.) / 332/F9029 (Parker Cross-Reference)
Pump Type: Tandem (dual-section) 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)
Drive Shaft: 1″ diameter, 15-tooth SAE splined shaft, 16/32 pitch
Mounting Flange: SAE B, 2-bolt flange
Inlet Port: Single 2″ SAE flange inlet
Front Pump Outlet: 1 1/16″-12 UNF threaded
Rear Pump Outlet: 7/8″-14 UNF threaded
Max. Working Pressure: 250 bar
Max. Input Shaft Torque: 460 Nm
Weight: Approx. 26 kg
332/F9028 – 33 + 23 cc/rev Configuration
Model: 332/F9028 (Parker OEM Part No.)
Pump Type: Tandem (dual-section) 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)
Drive Shaft: 1″ diameter, 15-tooth SAE splined shaft, 16/32 pitch
Mounting Flange: SAE B, 2-bolt flange
Inlet Port: Single 2″ SAE flange inlet
Front Pump Outlet: 1 1/16″-12 UNF threaded
Rear Pump Outlet: 7/8″-14 UNF threaded
Front Pump Max. Working Pressure: 250 bar
Rear Pump Max. Working Pressure: 275 bar
Max. Input Shaft Torque: 460 Nm
Weight: 26 kg
Power Rating: 82 HP builds
Replaces JCB Part Numbers: 20/925578, 20/925586
Compatible Models: JCB 3CX, 3DX, 4CX, 214-4, 215S, 217-4
Key Technical Advantages
1. Parker OEM Quality – 100% Drop-In Interchangeability
Manufactured to strict Parker Hannifin factory specifications, all mounting dimensions, flange interfaces, and spline shaft configurations are identical to original Parker pumps. End users can achieve direct drop-in replacement without any modifications — significantly reducing equipment downtime. The 20/925580, 20/925579, and 332/F9028 are fully interchangeable within the JCB OEM parts system, offering maximum procurement flexibility.
2. Tandem Pump Design – Two Pumps in One Compact Unit
The tandem (dual-section) gear pump configuration integrates two independent pump sections (front + rear) into a single housing, providing separate pressure oil sources for the main working hydraulics (loader/backhoe) and auxiliary systems (servo control/steering). This compact design saves installation space, reduces system complexity, and enhances overall hydraulic system reliability. The front and rear pumps feature different working pressure ratings (front 250 bar / rear 275 bar), optimized for the specific demands of each hydraulic circuit.
3. Three Displacement Configurations – Full JCB Model Coverage
This series offers three displacement options — 36+29 cc/rev (92-100 HP) , 36+26 cc/rev , and 33+23 cc/rev (82 HP) — comprehensively covering JCB 3CX, 3DX, 4CX, and 214/215/217 series backhoe loaders across different power ratings and hydraulic system configurations. A single product line covers a wide range of equipment types, significantly simplifying spare parts inventory management.
4. Precision-Ground Gears with Advanced Heat Treatment
Internal gear pairs are manufactured using precision grinding technology, achieving tooth profile accuracy meeting AGMA standards. Gear materials undergo case-carburizing and hardening heat treatment processes, delivering high surface hardness and exceptional wear resistance — capable of withstanding repeated high-load, high-speed冲击 over extended service life.
5. High-Strength Cast Iron Housing with Roller Bearings – Built for Harsh Conditions
The pump housing is constructed from high-strength cast iron with roller bearing construction, offering excellent rigidity, durability, and contamination tolerance. In demanding environments such as construction sites, mining operations, and agricultural fields — characterized by high dust levels, strong vibration, and extreme temperature fluctuations — the cast iron housing and roller bearing combination effectively protects internal precision components against external impact, thermal distortion, and oil contamination.
Application Areas
The Parker 20/925580 / 20/925579 / 332/F9028 series tandem gear pumps are widely compatible with the following JCB equipment models:
JCB Backhoe Loaders:
JCB 3C / 3CX Series (including 3CX-T, 3CXS, 3CXS-PC, 3CXSM, 3CX-4, 3CX SUPER)
JCB 3D / 3DX Series (including 3DX SUPER, 3DX XTRA)
JCB 4C / 4CN / 4CX Series (including 4CXM, 4CX-PC, 4CX444 SUPER, 4CN444 SUPER, 4CXSM444)
JCB 214 / 215 / 216 / 217 Series (including 214-4, 215S, 217-4)
JCB 3CXD14L4CM TIER 4 / 3CXG14L4CM
Other JCB Equipment:
JCB SD40, SD80, PD80, PD55, S55, PD70-LSD, PD70-MAXTRAC
Expert Maintenance Tips
1. Correct Model Selection – Understanding the Three Configurations
This series includes three different displacement configurations. Always verify the model number on the original pump nameplate before selection:
20/925580 (332/F9030) : Front 36 + Rear 29 cc/rev — for 92-100 HP standard builds
20/925579 (332/F9029) : Front 36 + Rear 26 cc/rev
332/F9028 : Front 33 + Rear 23 cc/rev — for 82 HP and Extra Dig application builds
2. Verify Rotation Direction – Critical Step
All three models in this series feature clockwise rotation (viewed from shaft end) . Always confirm the rotation direction of the original pump before installation. Incorrect selection will result in pump malfunction or catastrophic failure.
3. Distinguish PC (Precision Control) from Non-PC Models
Certain models are specifically designed for machines equipped with Precision Control (servo) systems (e.g., 4CX-PC, 3CXS-PC, 3CX-T-PC). Always verify machine serial number and hydraulic system configuration before selection.
4. Prime the Pump Before First Start
Fill the pump cavity with clean hydraulic fluid through the inlet port prior to initial startup. Dry-starting will cause rapid wear to gears and bearings under unlubricated conditions, potentially leading to catastrophic pump failure.
5. Replace Hydraulic Oil and Filters Simultaneously
When replacing the main hydraulic pump, we strongly recommend replacing all hydraulic oil and filters at the same time. Metal particles and contaminants in old oil will rapidly damage new pump internal components. The suction flange O-ring must also be replaced to ensure 100% seal on the suction line and prevent cavitation.
6. Maintain Fluid Cleanliness
For optimal Parker pump service life, we recommend a minimum filtration level of ISO 4406 19/17/14 or NAS 1638 Class 8. Regularly inspect filter elements to prevent contaminants from accelerating gear and bearing wear.
7. Periodic Torque Check on Mounting Bolts
Given the common use of these pumps in high-vibration equipment, we recommend checking mounting bolt and flange bolt torque every 500 operating hours to prevent loosening-induced leakage or misalignment.
8. Fault Diagnosis Indicators
Immediately shut down and inspect if any of the following abnormalities occur:
Unusual increase in pump operating noise (whining, grinding) – may indicate cavitation or bearing damage
Noticeably slower hydraulic operation (both loader and backhoe sluggish) – despite normal engine RPM
Loss of power – machine cannot lift rated loads
Rapid overheating of hydraulic oil
