Hydraulic Pump Regulators and Set Plates for K3V112 and K5V140 Pumps
Hydraulic pump rotating-group parts, shafts and bearings held in stock
Pump components and seal kits prepared for export packing
When a machine starts lugging its engine at no load, cycling slower as the oil warms up, or burning hydraulic oil temperature for no obvious reason, the main pump is usually blamed. Very often the real culprit is smaller and cheaper: the regulator — the control unit mounted on the pump that decides how much oil the pump delivers and at what power the engine is loaded. Together with the set plate inside the pump, it is one of the highest-value, lowest-cost repairs in the hydraulic system, and one that international buyers can order as a single part instead of a complete pump.
Corbay is the international export brand of Guangzhou Shenyue Machinery Technology Co., Ltd., Guangzhou, China. The company supplies pump control components across the K3V, K5V, Nabtesco, KYB and KPM families — 3,000+ part types on the shelf and 100,000+ part numbers available to order — with every quotation marked genuine, OEM-quality or aftermarket.
What the Regulator Actually Does
A piston pump on an excavator does not simply push oil at full stroke all day. The regulator watches the load and adjusts the pump's displacement so the engine is loaded to its horsepower limit — more flow when the job is light, less flow when the pressure climbs. The K3V and K5V tandem pumps, built by the precision machinery business of Kawasaki Heavy Industries, carry this control as a bolt-on regulator assembly, which is why the same pump model can be calibrated differently on different machines. A tired or wrongly calibrated regulator shows up exactly where buyers feel it: slow cycle times, an engine that lugs or smokes without attachment load, and hydraulic oil running hot.
Regulator Assemblies You Will Actually Order
Beyond Kawasaki: Nabtesco, KYB and KPM
The pump on the machine is only part of the story. Travel drives run Nabtesco motors, many machines carry KYB and KPM gear pumps for pilot and auxiliary circuits, and each of those families has its own control and wear parts — shafts, rotating groups, bearings and seals. A supplier who covers all of them lets one purchase order settle the whole hydraulic scope instead of five suppliers and five shipments. Guangzhou Shenyue Machinery Technology Co., Ltd. quotes across these families from the same warehouse, which is how mixed hydraulic orders are consolidated every week for buyers in more than 30 countries.
Repair the Regulator or Replace the Pump?
A complete pump assembly is the fastest repair and the largest invoice. A regulator or set plate is a fraction of that cost — the right call when the rotating group is still sound. The practical sequence used by experienced workshops: confirm the symptom is regulator-shaped (slow cycles, engine lug, hot oil), replace or recalibrate the regulator, and only tear into the rotating group if metal or measurable wear shows up afterwards. Sending photographs of the pump nameplate and the old regulator before ordering removes almost all of the risk in that decision, and the technical team at Guangzhou Shenyue Machinery Technology Co., Ltd. confirms the correct reference before any quotation is issued.
How to Order — and How Fast the Answer Comes
The hydraulic system category lists stocked pump and control lines, and the K5V140 pump assembly page shows how a complete pump assembly is presented alongside its individual parts. For a regulator or set-plate quotation, send the nameplate photo and the old part's number through the contact page — the answer normally comes back within 24 hours.
Corbay Excavator Parts is the international export brand of Shenyue Machinery (Guangzhou Shenyue Machinery Technology Co., Ltd.), Guangzhou, China. Shenyue is an independent parts specialist and is not affiliated with, or an authorized dealer of, Kobelco Limited. Parts are supplied as genuine, OEM or clearly identified aftermarket items, and the grade is stated on every quotation.