If your concrete pump truck or excavator starts showing signs of internal leakage, low pressure, weak pumping, or abnormal system heating, the root cause is likely worn or aging internal components of the hydraulic pump. For KAWASAKI pump models like K5V200, K3V112, long-term high-pressure use without timely part replacement can significantly reduce system performance.

So, what should you do when a hydraulic pump starts leaking or losing pressure? Here’s a breakdown of the causes and recommended replacement solutions:

Common Causes:

1. Worn valve plate sealing surfaces → causes internal backflow and loss of pressure

2. Loose or damaged piston assemblies → seal failure and insufficient flow buildup

3. Scored cylinder block or fatigue cracks → results in internal leakage and pressure loss

4. Loose drive shaft or damaged bearings → causes misalignment and unstable operation

5. Broken springs or ball guides → affects shift timing and system responsiveness

Recommended Parts to Replace:

• Valve plate (LH/RH) + cylinder block set

• Full piston & shoe assembly

• Drive shaft (left/right)

• Swash plate, support block, spring, ball guide, and other key motion components

Replacing a complete internal motion kit ensures balanced operation and eliminates mismatch issues between new and old parts.

Benefits After Replacement:

• Restored hydraulic pressure and output flow

• Reduced oil temperature and energy consumption

• Minimized cavitation noise and pressure spikes

• Extended service life and improved equipment efficiency

Pro Tip:

Always choose CNC-machined, heat-treated precision components from trusted suppliers. Low-quality parts can cause secondary damage. It’s also recommended to replace the hydraulic oil and filter during service to optimize overall system performance.