Piston Pump Series

Browse our complete range of hydraulic piston pumps engineered for heavy equipment applications. Hydraulic piston pumps are the core power source in excavators, loaders, and other construction machinery — responsible for driving boom, arm, bucket, swing, and travel hydraulic circuits with consistent pressure and flow.

HE PUMP stocks piston pumps for Caterpillar (CAT), Komatsu, Volvo, Hitachi, JCB, Liebherr, Kawasaki, Sany, XCMG, and more. Every pump is manufactured as a direct OEM-compatible replacement — designed to match or exceed original equipment specifications for displacement, pressure rating, and torque output.

How Does a Piston Pump Work?

An axial piston pump uses a rotating swash plate to drive pistons back and forth in a cylinder block. As the swash plate tilts, each piston strokes in and out, drawing in and pushing out hydraulic fluid. This design delivers high pressure, high efficiency, and variable displacement — making piston pumps the first choice for main hydraulic circuits in excavators and loaders.

Types of Piston Pumps We Supply

  • Variable displacement axial piston pumps: The most common type on modern excavators. Displacement adjusts automatically based on load demand, improving fuel efficiency
  • Fixed displacement piston pumps: Simpler design with constant displacement. Used where consistent flow is required regardless of load
  • Open-circuit piston pumps: Fluid flows from tank → pump → valve → tank. Most common on mobile equipment
  • Closed-circuit piston pumps: Fluid flows directly between pump and motor. Used on travel and swing drives where bidirectional control is needed

Common Applications

  • Main hydraulic pumps: The primary pump that powers boom, arm, bucket, and swing functions on excavators
  • Travel motors: Piston pumps (or piston motors) that drive track movement
  • Swing drives: Piston motors for upperstructure rotation
  • Loader hydraulics: Main pumps for wheel loader lift and tilt circuits
  • Dozer hydraulics: Blade lift, tilt, and ripper circuits

Equipment We Cover

  • Caterpillar Excavators: 320, 325, 330, 345, 349, 374 series
  • Caterpillar Wheel Loaders: 950, 966, 980, 988, 990 series
  • Caterpillar Motor Graders: 12M, 14M, 16M, 18M series
  • Caterpillar Bulldozers: D6, D8, D10, D11 series
  • Komatsu PC Series: PC200, PC300, PC400 series excavators
  • Volvo EC Series: EC220, EC300, EC380, EC480 series excavators
  • Other Brands: Hitachi, JCB, Liebherr, Sany, XCMG, and more

Why Choose HE PUMP Piston Pumps?

  • Direct Fit: No modifications required — bolt-on replacement for original pumps
  • OEM Quality Standards: Precision-machined components meeting or exceeding factory specifications
  • Broad Compatibility: Pumps available for hydraulic excavators, wheel loaders, motor graders, bulldozers, and more
  • 12-Month Warranty: Full coverage against manufacturing defects
  • Global Shipping: Fast worldwide delivery with competitive freight rates
  • Technical Support: We verify part numbers before shipping — contact us with your machine model and serial number

Signs of Piston Pump Failure

  • Sluggish or weak hydraulic movement (boom, arm, bucket response slows down)
  • Excessive noise — whining, growling, or knocking from the pump area
  • Overheating hydraulic fluid (internal leakage generates excess heat)
  • Metal particles in the hydraulic filter or suction screen
  • Visible external leaks at pump seals or housing
  • System pressure below specifications (test with a pressure gauge)

Preventing Piston Pump Failure

  • Replace hydraulic filters on schedule: Contaminated fluid is the #1 cause of piston pump failure
  • Use the correct hydraulic fluid: Wrong viscosity causes excessive wear and overheating
  • Avoid cavitation: Ensure the pump has adequate inlet pressure — restricted suction lines cause cavitation damage
  • Warm up the machine: Allow hydraulic fluid to reach operating temperature before full-load operation
  • Monitor case drain pressure: Excessive case pressure indicates internal wear and shortens pump life

Whether you need a complete piston pump assembly or internal replacement parts (piston shoes, valve plates, swash plates, cylinder blocks), we have you covered. Contact us today for part number verification, pricing, and availability.

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