Excavator KOMATSU PC30 PC35 PC40 PC45 Hydraulic Pump 708-1S-01111 708-1T-00142

Product Specification

Excavator KOMATSU PC30 PC35 PC40 PC45 Hydraulic Pump 708-1S-01111 708-1T-00142 708-1T-00512 708-1T-00141 Hydraulic Pump  Main  Hydraulic Pump

Here is the English translation for the Komatsu PC30 PC35 PC40 PC45 35MR hydraulic pump performance overview:
 Performance Overview of Komatsu 35MR Hydraulic Pump
The Komatsu PC35MR is a classic 3.5-ton mini excavator (spanning several generations, such as the -1, -2, -3, to -5). The **main hydraulic pump** equipped in this model is the core of the entire machine's power output and precise operation.
Below is the detailed technical breakdown and performance characteristics of the Komatsu 35MR hydraulic pump:
 1. Core Technology: CLSS (Closed-center Load Sensing System)
The biggest highlight of the Komatsu 35MR hydraulic system is its proprietary CLSS
 Perfect Multi-Function Synchronization:** In traditional fixed-displacement pump systems, simultaneous movements (e.g., digging, swinging, and traveling) often conflict, causing jerky actions or flow-stealing. The CLSS ensures that the main pump's flow is precisely distributed based on the actual demand of each control valve. Movements stay balanced and smooth, regardless of load variations.
 Flow-on-Demand & Fine Control:** The pump output depends entirely on how far the operator moves the joystick (offering excellent micro-control). It is independent of the load size, making it ideal for precision work in tight spaces like landscaping and municipal projects.
2. Key Performance Specifications
To ensure the mini excavator delivers fast cycle times while maintaining strong digging force, the main pump typically utilizes a triple-pump configuration consisting of a **variable double piston pump + a single gear pump**:
| Item | Performance Specs | Technical Description |

| Main Pump Type | Variable displacement axial piston pump times 2 + Gear pump times 1 | The piston pumps provide primary working power, while the gear pump typically handles pilot control or auxiliary circuits. |
| Maximum Total Flow | Approx. 36.1 times 2 + 19.8 text{ L/min} (Total flow ~ 92text{ L/min}) | Leading flow rates in its class, ensuring rapid machine response and quick cycle times. |
| Relief Valve Pressure** | Approx. 26.0 - 26.5 text{ MPa} (~ 3,770 text{ psi}) | High operating pressure translates directly to superior bucket/arm digging force and strong travel drawbar pull. |
3. Major Advantages
 High Fuel Efficiency:
   When the joysticks are in the neutral position (machine idling), the pump's swashplate automatically de-strokes to minimize flow. This "standby low power" design drastically reduces unnecessary hydraulic overflow energy losses, significantly cutting down fuel consumption.
 Excellent Durability & Leak Prevention:
   Komatsu's OEM pump internal components (pistons, valve plates, etc.) feature ultra-high manufacturing precision. The hydraulic lines heavily feature O-Ring Face Seals (ORFS)**. Compared to traditional tapered seals, ORFS provides superior vibration resistance and leak prevention, minimizing oil leaks in harsh working conditions.
 Instantaneous Response:
   Because the main pump responds to pilot control signals within milliseconds, the operator experiences seamless "hand-to-machine" synchronization with virtually zero lag.
 4. Maintenance & Parts Advisory
If you are looking for replacements or troubleshooting:
 Common OEM Part Numbers:708-3S-00514, 708-3S-00961, 708-3S-00461, etc. (These vary slightly by machine generation/series, so always verify using your machine's serial number).
 Maintenance Tip: This variable piston pump is highly sensitive to oil contamination. Ensure that the hydraulic return filter and pilot filter are replaced regularly. Any fine metal debris or contaminants will wear down the pistons, leading to internal leakage, speed loss, or engine stalling under load.