R900568431 Bosch Rexroth Pilot-Operated Pressure Reducing Valve / Proportional Pressure Reducing Valve (Model: FTDRE4K12). Widely used in excavators, construction machinery, and industrial hydraulic systems.

I. Key Specifications

Order Number: R900568431

Brand: Rexroth

Type: Pilot-Operated Pressure Reducing Valve / Proportional Pressure Reducing Valve (FTDRE4K12)

Nominal Size: 4mm (Cartridge Type)

Pressure Range: 0–315 bar

Control Method: Proportional Solenoid Control (24VDC)

Function: Receives electrical signals to output a stable secondary pressure; used for precise pressure regulation in hydraulic pilot controls, braking systems, travel motors, swing motors, etc.

II. Compatible Models (Mainstream)

Excavators: Mainstream models from Sany, XCMG, Liugong, SDLG, Caterpillar, Komatsu, Kobelco, etc.

Construction Machinery: Wheel loaders, road rollers, asphalt pavers, concrete pump trucks.

Industrial Hydraulics: Injection molding machines, die-casting machines, machine tools, metallurgical equipment.

IV. Common Faults and Diagnostics

Fault Symptoms: Unstable pressure, low secondary pressure, weak actuator movement, abnormal system noise, oil leakage.

Diagnostic Methods:

Measure coil resistance (normally approx. 15–30Ω).

Check for oxidation on connector pins, or damage/short circuits in the wiring harness.

Use a pressure gauge to test the secondary pressure and compare the actual value against the setpoint.