723-20-61502 Hydraulic Relief Valve for Komatsu PC75UU-3, PC75US, PC78US

   The 723-20-61502 relief valve is a critical "fail-safe" for the hydraulic circuit. In the Komatsu PC75 and PC78 series, which are often used for utility work near buildings or traffic, consistent hydraulic response is vital. This valve prevents the system pressure from exceeding safe thresholds, which would otherwise lead to blown hoses or internal damage to the expensive piston pumps.

The SPARKLING MACHINERY NEW 723-20-61502 Relief valve Photo:

Why Choose the SPARKLING 723-20-61502 Relief valve?

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • •   - Precision Pressure Setting: Factory-calibrated to match the specific flow requirements of Komatsu's intermediate-class excavators.

                                                          •   - Shock Suppression: Designed to handle rapid pressure spikes when the arm or bucket hits an immovable object (like a buried concrete slab).

                                                          •   - High-Grade Steel Construction: Features a hardened poppet and seat to resist "wire-drawing" and erosion caused by high-velocity hydraulic oil.

                                                          •   - Corrosion Resistant: Treated surface to prevent rusting and seizing within the control valve block, ensuring easy removal for future maintenance.

                                                •  

Q&A Section

Q1: How do I know if the 723-20-61502 valve needs to be replaced?

A: If your machine loses power across all hydraulic functions (boom, arm, and travel are all weak) or if you hear a constant "hissing" sound from the control valve when under load, the relief valve may be stuck open or its internal spring may be broken.

Q2: Can this valve be adjusted to increase the machine's lifting capacity?

A: While there is an adjustment nut, it should only be turned while monitoring a hydraulic pressure gauge. Increasing pressure beyond Komatsu's specifications can cause structural cracks in the boom or catastrophic failure of the main pump.

Q3: Is the 723-20-61502 the same as a "Suction" valve?

A: No. A suction valve (or make-up valve) prevents cavitation by allowing oil into a cylinder, whereas the 723-20-61502 relief valve is designed to let oil out of the system when pressure is too high.

About SPARKLING MACHINERY:
   - Founded in 2013, SPARKLING focuses on high-quality excavator parts across hydraulics, undercarriage, engines and electrical systems. We prioritize stability, precision and continuous service, offering worldwide distribution, tailored solutions and strict QC to help customers reduce cost and increase uptime.

   Get In Touch:
   - Replace your failing ECU confidently. Contact SPARKLING for pricing, lead time, and technical support — restore optimal machine control quickly and reliably.