20/912800 JCB Hydraulic Gear Pump | 33+29cc 275 bar for 3CX/4CX

Product Overview

The 20/912800 (also referenced as 702912209) is a heavy-duty twin hydraulic gear pump manufactured by Parker Hannifin for JCB 3CX / 4CX series backhoe loaders. This model features a tandem (twin-section) gear pump configuration with a front pump displacement of 33 cc/rev and a rear pump displacement of 29 cc/rev. Two independent pump stages are 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, this pump features 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, this model fully complies 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 & Part Number Reference:

• 20/912800 — JCB Primary Part Number

• 702912209 / 7029122091 — Parker Cross-Reference Part Numbers

• 20/902900 — Alternative Part Number

• 400/E0868 — Alternative Part Number

• Manufacturer: Parker Hannifin (OEM Quality)

Technical Specifications (Bulleted List)

• Model: 20/912800 (JCB Part Number)

• Cross References: 702912209 / 7029122091, 20/902900, 400/E0868

• Manufacturer: Parker Hannifin (OEM Quality)

• Pump Type: Tandem Twin Gear Pump

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

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

• Maximum Working Pressure (Front Pump): 275 bar

• Maximum Working Pressure (Rear Pump): 275 bar

• Rotation Direction: Counter-Clockwise (viewed from shaft end)

• Drive Shaft: 1-inch (25.4 mm), parallel keyed shaft

• Mounting Flange: SAE B, 2-bolt flange

• Inlet: Combined 2-inch SAE flange

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

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

• Maximum Input Shaft Torque: 325 Nm

• Weight: Approx. 23 – 26 kg

• Speed Range: 600 – 3000 rpm

• Housing Material: High-strength cast iron

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

Key Technical Advantages

1. Twin Pump Design – One Pump, Two Circuits
The 20/912800 features a Parker twin gear pump configuration with front (33 cc/rev) and rear (29 cc/rev) stages driven by a common input shaft, enabling independent oil supply to both the loader and excavator hydraulic systems of the backhoe loader. Both stages share a common suction port, allowing stable and simultaneous operation of multiple hydraulic circuits.

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. Large Displacement with High Flow Output
With 33 cc/rev front and 29 cc/rev rear displacement, each stage delivers 33 L/min and 29 L/min respectively at 1000 rpm. When combined, the two stages can deliver up to 62 L/min total flow—fully meeting the high-flow demands of backhoe loader operations including digging, lifting, and loading.

4. High-Pressure Capability for Heavy-Duty Applications
Both front and rear pumps deliver maximum working pressure of 275 bar, fully meeting the high-pressure demands of heavy-duty backhoe loader operations. Maximum input shaft torque reaches 325 Nm, ensuring reliable power transmission under extreme loads.

5. JCB OEM Specification – 100% Direct Interchangeability
This model is manufactured to JCB / Parker original technical specifications, with flange dimensions, shaft specifications, and mounting interfaces identical to OEM pumps. 20/912800 is cross-compatible with 702912209, 20/902900, and 400/E0868—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 original design performance standards.

Application Areas

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

• JCB 3CX Backhoe Loaders: 3CX Centremount, 3CX Sideshift, 3CX Sitemaster, 3CX Contractor, 3CX SUPER, 3CX 444 SUPER and all series variants

• JCB 4CX Backhoe Loaders: 4CX series

• JCB 3DX Backhoe Loaders: 3DX series

• Other JCB equipment compatible with 20/912800, 20/902900, and 400/E0868 part numbers

Expert Maintenance Tips

1. Model Confirmation
20/912800 and 702912209 are different catalog numbers for the same product. Before installation, always verify the complete part number on the original pump nameplate—it may be marked as 20/912800, 702912209, 20/902900, or 400/E0868, all of which are fully equivalent.

2. Rotation Direction Confirmation
This model features counter-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 parallel keyed 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 combined 2-inch SAE flange; the front pump outlet is 1 1/16″-12 UNF threaded and the rear pump outlet is 7/8″-14 UNF threaded—ensure correct thread specifications during connection

• Must completely depressurize the hydraulic system before installation—lower all attachments to the ground and operate all levers with the engine off

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—while cast iron pumps are more durable than aluminum counterparts, they remain sensitive to cavitation

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

• Flush the entire hydraulic system before installing a new pump to remove metal particles from previous pump wear

6. Periodic Maintenance

• Check mounting bolt torque every 1,000 operating hours

• Regularly monitor operating pressure of both stages to ensure they do not exceed 275 bar

• If flow output decreases, loss of power on all hydraulic functions, very slow hydraulic response (especially when oil is warm), loud whining noise indicating cavitation or internal wear, overheating of hydraulic oil, or metal particles found in hydraulic oil or filter—inspect and replace worn components promptly