Product Overview
The G5-8-1E13S-20R is a representative model of the Parker Hannifin G5 series high-pressure external gear pumps, featuring a displacement of 8 cc/rev and a rated pressure of 25 MPa (approx. 250 bar) , with operating speeds up to 4000 r/min.
The G5 series gear pumps are manufactured using proprietary technology introduced from VICKERS (USA), featuring a three-piece construction design. The pump consists of a front cover, center section, rear cover, and a pair of alloy steel gears. The front cover, center section, and rear cover are manufactured from aluminum alloy, with two DU composite bearings pressed into each of the front and rear covers. A pressure plate is installed in the rear cover, enabling automatic axial clearance compensation and radial pressure balancing. The G5 series gear pumps can be configured as double pumps and four-section pumps.
The G5 series gear pumps feature advanced performance, reliable operation, compact size, light weight, and cost-effectiveness. The series offers various mounting flanges, shaft extensions, and inlet/outlet port connections compliant with SAE and national standards. The G5-8-1E13S-20R is widely used in hydraulic systems for construction machinery, mobile equipment, and other industrial machinery.
Engineered as a direct OEM-replacement solution for Parker/VICKERS original products, the G5-8-1E13S-20R fully complies with Parker original design standards and SAE 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 Code Breakdown (Bulleted List) :
G5 — Series: G5 High-Pressure External Gear Pump
8 — Displacement code: 8 cc/rev nominal displacement (G5 series offers 5.2 – 30.1 cc/rev)
1E13S — Shaft and configuration code (shaft type, flange specifications, etc.)
20 — Design series code
R — Rotation direction: R = Clockwise (viewed from shaft end)
Technical Specifications
Model: G5-8-1E13S-20R
Brand: Parker Hannifin / VICKERS technology
Series: G5 High-Pressure External Gear Pump
Displacement: 8 cc/rev
Rated Pressure: 25 MPa (approx. 250 bar)
Maximum Speed: 4000 r/min
Construction: Three-piece construction
Housing Material: Aluminum alloy (front cover, center section, rear cover)
Gear Material: Alloy steel
Bearing Type: DU composite bearings (two in each cover)
Pressure Compensation: Automatic axial clearance compensation + Radial pressure balancing
Rotation Direction: Clockwise (R = Right-hand)
Mounting Flange: SAE standard flange / GB national standard flange
Operating Temperature: 0 – 120℃
Recommended Media: Hydraulic oil
Material: Cast iron
Key Technical Advantages
1. VICKERS Licensed Technology – Proven Quality
The G5 series gear pumps are manufactured using proprietary technology introduced from VICKERS (USA). VICKERS is a world-leading hydraulic component manufacturer, and its technology platform ensures high quality and reliability.
2. Three-Piece Construction + DU Composite Bearings – Long Life & High Reliability
The three-piece construction design consists of a front cover, center section, rear cover, and a pair of gears. Two DU composite bearings are pressed into each of the front and rear covers. DU material is an ideal bearing material for gear pumps, significantly extending pump service life.
3. Automatic Axial Clearance Compensation + Radial Pressure Balancing – High Efficiency & Low Leakage
A pressure plate installed in the rear cover enables automatic axial clearance compensation and radial pressure balancing. The pressure plate is the primary component for radial and axial pressure compensation, reducing bearing loads and automatically adjusting gear axial clearance to effectively enhance pump performance and reliability.
4. Superior High-Pressure & High-Speed Capability
Rated pressure of 25 MPa (approx. 250 bar) with operating speeds up to 4000 r/min. The combination of high-strength aluminum alloy housing and alloy steel gears ensures long-term stability under high-pressure and high-speed conditions.
5. Flexible Configuration & Combination Capability
The G5 series offers various mounting flanges, shaft extensions, and inlet/outlet port connections compliant with SAE and national standards. G5 series gear pumps can be configured as double pumps and four-section pumps.
6. Wide Displacement Coverage – Flexible Selection
The G5 series offers displacements from 5.2 to 30.1 cc/rev. The G5-8-1E13S-20R (8 cc/rev) is a mainstream model in this series, suitable for medium-flow hydraulic systems.
7. 100% Factory Tested & Direct Interchangeability
Every unit undergoes 100% workload simulation testing prior to shipment, covering pressure retention verification, internal leakage detection, and flow validation. Fully compliant with Parker/VICKERS original design standards, with flange dimensions, shaft specifications, and mounting interfaces identical to OEM pumps—direct drop-in replacement with zero modifications required.
Application Areas
The G5-8-1E13S-20R gear pump is widely used in the hydraulic systems of the following equipment:
Construction Machinery: Excavators, loaders, bulldozers, and other mobile machinery
Mobile Equipment: Various mobile hydraulic equipment
Industrial Equipment: Hydraulic power units (HPU), manufacturing machinery, automation equipment, press machines
Agricultural Machinery: Tractors, combine harvesters, and agricultural equipment
Material Handling Equipment: Forklifts, lift platforms
Mining Machinery: Mining equipment hydraulic systems
Marine Equipment: Marine hydraulic systems
Expert Maintenance Tips
1. Model Confirmation
The G5-8-1E13S-20R offers 8 cc/rev displacement. The G5 series also includes G5-5, G5-6, G5-10, G5-12, G5-16, G5-20, G5-25, G5-30, and other displacement options. Before installation, confirm the correct displacement based on system flow requirements and verify the complete model code on the pump nameplate.
2. Rotation Direction Confirmation
Suffix “R” indicates clockwise rotation (viewed from shaft end), “L” indicates counter-clockwise rotation. 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 standard mounting flange and shaft mating surfaces before installation to ensure no debris remains
The G5 series offers various mounting flanges, shaft extensions, and inlet/outlet port connections compliant with SAE and national standards
Use Parker-specified torque values for mounting bolts—avoid over-tightening which may cause distortion of the aluminum housing
Ensure correct connection of inlet and outlet ports—the inlet line must have no restrictions or sharp bends
Clean the inside of piping with high-pressure oil before installation to prevent hard particles from entering
4. First Start-Up and Bleeding
Before first start-up, must fill the pump 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 the system
Check for abnormal noise or leakage—aluminum housing pumps are particularly sensitive to cavitation
5. Fluid and Filtration
Use high-quality anti-wear hydraulic oil compliant with standards
Maintain operating temperature within 0 – 120℃
Maintain system oil cleanliness to ISO 4406 18/15 or better
Regularly replace return line filters to prevent contaminants from entering the pump
6. Periodic Maintenance
Check mounting bolt torque every 1,000 operating hours
Regularly monitor system operating pressure—not to exceed 25 MPa rated pressure
DU composite bearings provide excellent self-lubrication—nevertheless, regularly inspect shaft seals to prevent leakage
If flow output decreases, noise levels increase abnormally, or system temperature rises excessively, inspect and replace worn components promptly
