5423-518 Eaton Mixer Truck Hydraulic Pump 89cc 420bar

Product Overview

The 5423-518 is an Eaton ACA Series heavy-duty variable axial piston pump designed specifically for closed-circuit hydrostatic transmission systems in concrete mixer trucks. It features a maximum displacement of 89.1 cm³/rev, rated working pressure of 420 bar (6,000 psi), and peak pressure of 480 bar (7,000 psi). The pump utilizes a swashplate variable design with hydraulic servo control, enabling stepless displacement adjustment from zero to maximum to precisely control drum rotation speed and ensure uniform concrete mixing during transport.

The Eaton ACA series pump is designed to operate with HHD series fixed displacement motors (5433-138, 6433-042, etc.) to form a complete mixer truck hydraulic drive system. The 5423-518 pump paired with the 5433-138 motor is widely used in 8-12 m³ mixer trucks and is the standard hydraulic configuration for mainstream mixer truck chassis worldwide. The high-strength cast iron housing provides superior noise damping and wall strength to withstand the demanding duty cycles of frequent starts and long-haul transport.

Manufactured to exact Eaton OEM specifications, every unit features mounting dimensions, flange interfaces, and port layouts fully consistent with the original pump for true drop-in interchangeability. Each pump undergoes 100% simulated operating condition testing before shipment, covering rated pressure loading, displacement response, and housing sealing integrity.

Technical Specifications 

• Model: 5423-518

• Series: Eaton ACA Series (Heavy-Duty Variable Pump)

• Pump Type: Axial piston variable pump, swashplate design, closed circuit

• Maximum Displacement (at 18° swashplate angle): 89.1 cm³/rev (5.44 in³/rev)

• Displacement Range: 0 – 89.1 cm³/rev (stepless variable)

• Rated Working Pressure: 420 bar (6,000 psi / 42 MPa)

• Peak Pressure: 480 bar (7,000 psi / 48 MPa)

• Maximum Shaft Speed (at 18°): 3,720 rpm

• Maximum Shaft Speed (at 10°): Approx. 4,810 rpm

• Control Type: Hydraulic servo control

• Mounting Flange: SAE-C 4-bolt flange

• Housing Material: High-strength cast iron

• Matched Motor: Eaton 5433-138 (89.1 cm³/rev) or 6433-042 (105.5 cm³/rev)

• Compatible Mixer Drum Capacity: 8-12 m³

• Recommended Hydraulic Fluid: ISO VG 46 anti-wear hydraulic oil

• Fluid Temperature Range: -20 °C to +90 °C

Key Technical Advantages

1. Purpose-Built for Closed-Circuit Hydrostatic Transmissions: The Eaton ACA series pump is specifically developed for closed-circuit hydrostatic transmission systems in mixer trucks. Pump output flow is precisely regulated via hydraulic servo control to drive HHD series fixed displacement motors for drum rotation. Whether the truck is traveling down a highway or idling at a traffic light, the drum maintains a consistent rotation speed, ensuring uniform concrete quality.

2. High Displacement and Pressure Output: The 5423-518 delivers 420 bar rated pressure at 89.1 cm³/rev displacement, providing high pressure and large flow output to meet mixer truck drive requirements under all operating conditions. High-strength swashplate design resists deflection under high loads, ensuring precise control of the variable mechanism.

3. Hydraulic Servo Control with Low Operating Effort: The pump is equipped with a hydraulic servo control system featuring large servo pistons that hold the swashplate position and provide damping, enabling low operating effort at low control pressures with responsive control. Operators can easily and precisely adjust drum rotation speed.

4. High-Strength Cast Iron Housing with Noise Damping: The high-strength cast iron housing provides greater wall strength to withstand high pressures while delivering superior noise damping characteristics. Large case drain ports minimize case back pressure, reducing shaft seal leakage risk.

5. System Compatibility and Drop-In Interchangeability: The 5423-518 pump forms a complete mixer truck hydraulic system ecosystem with Eaton 5433-138 motor, 6423-279 pump, and 6433-042 motor. Mounting flanges and port layouts meet Eaton OEM standards, allowing direct replacement of same-specification original pumps without piping or coupling modification. Widely compatible with IVECO, Shacman, Howo, and other mainstream mixer truck chassis.

Application Areas

• 8-12 m³ Concrete Mixer Trucks: IVECO 9cbm mixer trucks, Shacman 8/9CBM mixer trucks, Howo mixer trucks

• All Brands of Concrete Mixer Trucks: OEM and aftermarket for mixer trucks equipped with Eaton ACA/HHD hydraulic systems

• Road Construction Machinery: Mobile machinery requiring closed-circuit hydrostatic transmissions

• Industrial Hydraulic Systems: Industrial equipment requiring high-pressure variable pump drives

Expert Maintenance Tips

1. Hydraulic System Initial Flushing and Filling: Thoroughly flush hydraulic lines and replace all system filter elements before pump installation. Pre-fill the pump housing with clean ISO VG46 anti-wear hydraulic oil through the case drain port. For closed-circuit systems, also verify proper operation of the charge pump circuit.

2. Servo Control System Inspection: The 5423-518 uses hydraulic servo control. During initial startup, verify that servo control pressure is normal. The servo piston should hold the swashplate position stably. If drum speed fluctuation is observed, inspect the servo control circuit for leakage or blockage.

3. Case Drain Line Configuration: The large case drain port is a design feature of this pump. The case drain line must return directly to the reservoir with backpressure not exceeding 2 bar. The drain line inner diameter must be sufficient to ensure unobstructed drainage during cold-start high-viscosity conditions, preventing shaft seal damage from excessive backpressure.

4. Fluid Cleanliness Management: Use ISO VG46 anti-wear hydraulic oil with system filtration of β10 ≥ 75. Closed-circuit systems require high fluid cleanliness. Replace filter elements after the first 500 operating hours, then every 1,000 hours or annually thereafter.

5. Drum Speed Verification: After pump installation, verify that drum rotation speed under rated conditions is within specification (typically 1-2 rpm for mixing, 12-14 rpm for discharging). If speed is abnormal, check the pump displacement control setting and motor operating condition.