121-1490 Caterpillar Hydraulic Pump Rotary Solenoid Valve (also known as the Hydraulic Pump Proportional Solenoid Valve) is used to control the flow and pressure of the main pump; it serves as a core hydraulic control component for Caterpillar excavators.

I. Core Parameters

Model: 121-1490 (1211490)

Type: Rotary Proportional Solenoid Valve (Rotary Solenoid)

Voltage: 24V DC

Compatible Models: KWE5K-31/G24YA30, SKY5G24-D

Interface: 2-pin connector, standard hydraulic mounting

Material: Alloy Steel / Stainless Steel

II. Function and Application

Function: Receives electrical signals from the ECU; regulates hydraulic fluid flow via a rotating spool valve; controls the swashplate angle of the main pump; and facilitates the control of excavator movement speed, compound movements, and power matching.

Applicable Models (Primarily Excavators):

311B, 312B/C/D, 315C, 320B/C/D, 322C, 325B/C/D, 330B/C/D, 345B

Engines: 3066, 3126, 3176C, C7, C9, C13, etc.

III. Alternatives and Procurement

Replacement Models: CTP H1211490, CA1211490, 121-1491