KMX15 4281788 Main Control Valve Assembly for Hitachi EX120-2 Excavator

Are you experiencing severe boom drop under neutral loads, sluggish arm-in coordination, or high hydraulic oil heat during digging on your Hitachi EX100-2 / EX120-2? The KMX15 4281788 Main Control Valve Assembly by Tatan is custom-engineered to eradicate internal pressure bypass across aging Dash-2 hydraulic circuits. Featuring micro-lapped alloy spools and factory-preset 31.4 MPa relief valves, this unit drops straight into your original frame without plumbing alterations.

Need Port Alignment & Direct Factory Pricing for EX120-2 Valve?

Contact Senior Specialist Gavin for free machine nameplate double-check & freight quote:

What Fleet Owners & Workshops Get from Tatan:

  • Stops Neutral Drift & Sinking: Hardened check-valve poppets hold bucket loads securely without hydraulic creep when joysticks are neutral.
  • 1:1 Original Port Configuration: Engineered precisely to match Hitachi EX120-2 pilot line angles and main pump high-pressure hard pipes.
  • Pre-Calibrated Relief Settings: Main safety relief calibrated to 31.4 MPa and port overloads to 34.3 MPa on automated test benches.
  • Sub-Micron Bore Honing: Spool clearances under 0.003 mm prevent high-pressure oil bypass, eliminating unnecessary hydraulic oil heating.
  • Complete Turnkey Assembly: Delivered ready to install with main relief cartridges, load checks, and pilot caps intact; backed by a 12-month warranty.

Description

KMX15 4281788 Main Control Valve Assembly Overview

The KMX15 4281788 Main Control Valve assembly (OEM Part Numbers: 4281788, 4192631, 4216839, KMX15) manufactured by Tatan is a heavy-duty hydraulic distribution manifold engineered specifically for the Hitachi EX120-2, EX120-3, and EX120-5 12-to-13 ton excavators. On legacy machines where internal bore wear triggers multi-circuit oil cross-leaks and boom drop, installing a brand-new KMX15 4281788 Main Control Valve unit restores precise 31.4 MPa hydraulic pressure and smooth multi-actuator responsiveness instantly.

Forged from high-density alloy iron and precision-machined with micro-lapped internal spool channels, this valve interfaces cleanly with the Isuzu 4BD1 engine output and original pilot control lines without modification.

⚠️ Technical Verification for EX120-2 Owners: Hitachi EX120-2 and EX120-3 series can experience minor differences in auxiliary hydraulic circuit plumbing or return line sizes. Please send a nameplate photo or port layout to Gavin for free verification prior to dispatch.

Key Attributes & Parameters for KMX15 4281788 Main Control Valve

Product CategoryMain Control Valve AssemblyWarranty1 Year / 12 Months
Specific Valve ModelKayaba KMX15 Multi-Spool ValveBrand NameTatan
Compatible EquipmentHitachi EX120-2 | EX120-3 ExcavatorOEM Part Number4281788 / KMX15
Matched Engine SeriesIsuzu 4BD1 / 4BD1T Diesel EnginePlace of OriginGuangdong, China
Main Relief Setting31.4 MPa (314 bar / 4550 PSI)Overload Port Relief34.3 MPa (343 bar / 4970 PSI)
Spool Bore ToleranceSub-Micron Lapped < 0.003 mmHydraulic Port SpecJIS 30° Metric Flare Standard
Machinery Test ReportProvided (100% Bench Tested)Video Outgoing-InspectionProvided Before Shipping
Quality Status100% Brand New Complete UnitPackagingExport Wooden Box Packaging

Supported Machinery Brands & Control Valve Coverage

In addition to Hitachi, Tatan manufactures replacement main control valves and hydraulic distribution manifolds for leading excavator brands:

Tatan Compatible Excavator Machinery Brands Display Hitachi Komatsu Caterpillar Kobelco Volvo Doosan

Application Scenarios & Buyer Value

When rebuilding or replacing aging hydraulic systems with our KMX15 4281788 Main Control Valve, workshops and equipment owners eliminate repetitive downtime:

Application ScenarioValue Delivered to Buyer
EX120-2 Hydraulic RestorationStops boom/arm drift and restores crisp, multi-function simultaneous digging performance.
Excavator Overhaul WorkshopsAvoids the high cost and unreliability of re-honing worn out 25-year-old valve bodies.
General Earthmoving ContractorsProvides stable flow routing for heavy trenching and backfilling without fluid overheating.
Export Parts StockistsReadily available replacement valve assembly ready for immediate dispatch to international clients.

KMX15 4281788 Main Control Valve OEM Diagnostic Guide

Use this technical diagnostic guide to identify hydraulic faults originating in the main control valve on your Hitachi EX120-2:

Hydraulic SymptomTechnical Cause AnalysisTatan Factory-Grade Solution
1. Boom drops rapidly when joystick is neutralErosion on the boom load holding check valve poppet seat, or excessive internal clearance.Install Tatan complete KMX15 4281788 Main Control Valve unit; flush system and replace pilot filter.
2. Weak bucket and arm breakout forceMain safety relief valve setting pressure drop (<31.4 MPa) or internal spool land bypass.Verify pump pressure; if sound, replace with Tatan pre-calibrated control valve assembly.
3. Hydraulic fluid temperature spikes rapidlyHigh-pressure oil continuously short-circuiting across worn spool lands into tank return gallery.Replace complete monoblock assembly to restore tight <0.003 mm tolerances and eliminate heat.
4. External fluid pooling around pilot end capsHardened, brittle NBR pilot end-cap O-rings failing under pressure spikes.Tatan valve comes pre-fitted with high-temp fluororubber (FKM) seals rated for heavy cycling.

Transport Packaging & Fast Global Shipping

To ensure 100% damage-free international transport, every Tatan KMX15 4281788 main control valve is preserved with anti-corrosion oil, sealed in heavy poly film, and strapped inside an export-grade wooden crate.

Global shipping supported by multiple logistics companies DHL FedEx UPS Sea Air Freight

✈️ Express Air Courier

Partnered with DHL, FedEx, UPS, and TNT for 3-7 day express door-to-door delivery worldwide.

🚢 Sea Cargo Freight

LCL and FCL ocean container shipping for heavy control valve assemblies and bulk orders.

📦 Export Wooden Cases

Fumigated solid wooden boxes with custom high-density foam inserts to prevent shipping shock.

Quality Control & International Certificates

Tatan hydraulic components are manufactured under ISO 9001 certified quality control systems and strictly comply with CE safety standards.

Tatan Quality Assurance ISO9001 CE Qualification Certificates

KMX15 4281788 Main Control Valve FAQ & Related Categories

Q1: Is this KMX15 4281788 Main Control Valve assembly a direct replacement for Hitachi EX120-2 excavators?
A: Yes. This assembly matches original Hitachi specifications for EX120-2 and EX120-3 slewing and linkage mountings.
Q2: Are the relief valves pre-calibrated or do they need adjustment in the field?
A: All main safety relief and port overload relief valves are pre-set and calibrated to factory specifications (31.4 MPa main / 34.3 MPa overload) on our hydraulic test bench before dispatch.
Q3: What are the primary OEM part numbers associated with this Hitachi EX120-2 control valve?
A: Common OEM reference numbers include 4281788, 4192631, 4216839, and KMX15.

Get Wholesale Factory Quote for KMX15 4281788 Main Control Valve

Looking for direct factory pricing, stock availability, or technical verification for KMX15 4281788 main control valves? Contact senior specialist Gavin now!

💡 Fast Quote: Send your machine serial number or old control valve photos for a 100% accurate match within 10 minutes!

* Note: Wholesale Reference Price Starts From $300.00. Please contact Gavin for a final customized quote.

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