Piston Pump Parts Series

Hydraulic piston pump rebuild kits and replacement parts let you restore pump performance at a fraction of the cost of a new pump. Instead of replacing the entire pump assembly, replace only the worn internal components — getting your machine back to full power quickly and affordably.

HE PUMP supplies piston pump parts for Caterpillar, Komatsu, Volvo, Hitachi, Kawasaki, Rexroth, and other major hydraulic pump brands. Every part is manufactured to OEM dimensional and material specifications.

What's in a Piston Pump Rebuild Kit?

A complete piston pump rebuild kit typically includes:

  • Piston Shoes (Piston Slippers): The wear surfaces that ride against the swash plate. Worn shoes cause reduced flow and overheating
  • Cylinder Block (Barrel): The rotating block containing the pistons. Worn cylinder blocks cause internal leakage and pressure loss
  • Valve Plate (Port Plate): The stationary plate with intake and discharge ports. Scored or worn valve plates cause excessive bypass
  • Swash Plate: The angled plate that converts rotary motion into piston stroke. Worn swash plates cause reduced displacement
  • Retainer Plate (Ball Guide): Holds the piston shoes against the swash plate. A damaged retainer plate causes piston misalignment
  • Center Pin (Pivot Pin): Supports the cylinder block and swash plate. Worn pins cause excessive wobble and noise
  • Seal Kit: O-rings, gaskets, and shaft seals for a complete rebuild

When to Rebuild Your Piston Pump

Consider a rebuild when you notice:

  • Sluggish hydraulic movement (boom, arm, bucket response slows down)
  • Excessive noise — whining, growling, or knocking from the pump area
  • Overheating hydraulic fluid
  • Metal particles in the hydraulic filter or suction screen
  • System pressure below specifications

A timely rebuild costs a fraction of pump replacement — and prevents catastrophic failure that could damage other hydraulic components.

Compatible Brands & Pump Models

Our piston pump parts fit pumps from:

  • Caterpillar: CAT 320, 325, 330, 345, 349, 374 series excavators
  • Komatsu: PC200, PC300, PC400 series excavators
  • Volvo: EC220, EC300, EC380, EC480 series excavators
  • Hitachi: ZX series excavators
  • Kawasaki: K3V, K5V, M5X, M7X series pumps and motors
  • Rexroth: A4VG, A6VM, A2FM series pumps and motors
  • Liebherr: Various swash plate and bent-axis piston pumps

Rebuild vs. Replace — Which is Right?

Rebuild (replace internal parts):

  • ✅ Lower cost — pay only for wearing parts
  • ✅ Faster turnaround — no need to wait for a complete pump
  • ✅ Reuse the pump housing and hard parts
  • ⚠️ Requires clean workshop and proper tools
  • ⚠️ Not recommended if the pump housing is scored or damaged

Replace (complete pump assembly):

  • ✅ Guaranteed like-new performance
  • ✅ No risk of missed wear items
  • ✅ Simpler installation — bolt-on replacement
  • ❌ Higher cost
  • ❌ Longer lead time if the pump is not in stock

Not sure which option is best? Contact us — our technical team will help you decide.

Why Choose HE PUMP Piston Pump Parts?

  • OEM-Compatible Quality: Precision-machined to original specifications
  • Complete Kits Available: Full rebuild kits or individual components — order exactly what you need
  • 12-Month Warranty: Full coverage against manufacturing defects
  • Expert Support: We help you identify the correct parts for your pump model
  • Global Shipping: Fast delivery worldwide

Browse our piston pump parts by pump model, or contact us with your pump nameplate photo for fast, accurate parts identification.

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