COMPONENT OPERATION / Signal Control Valve OUTLINE The signal control valve is provided in the pilot circuit between pilot valve and control valve, and controls various signal pressure used to regulate the pumps and valves. The major components of signal control valve are shuttle valve, shockless valve, flow combiner valve control spool, arm flow rate control valve control spool and swing parking brake release spool.
Section A-A Shockless Valve (For Boom Raise) Auxiliary Arm Flow Rate Control Valve Control Spool Auxiliary Auxiliary Swing Parking Brake Release Spool Flow Combiner Valve Control Spool A, B T178-03-06-002 Section B-B (Shuttle Valve) Pilot Valve Side T1J1-03-06-004 T178-03-06-009 1 - Left Travel 6 - Swing 11 - Arm / Boom Raise 16 - Boom / Arm / Bucket / Left Travel / Swing 2 - Right Travel 7 - Auxiliary 12 - Boom / Arm / Bucket / Swing / Auxiliary 17 - Left Travel / Right Travel 3 - Bucket 8 - Swing / Auxiliary 13 - Boom / Arm / Bucket 4 - Arm 9 - Boom / Arm 14 - Boom / Arm / Bucket / Left Travel 5 - Boom 10 - Arm / Boom Raise / Swing / Auxiliary 15 - Boom / Arm / Bucket / Right Travel T3-6-1 11 4 9 6 13 15 2 14 17 5 8 7 10 3 16 12 1 17