HOSE AS-GUARD 5464703 - Caterpillar

Illustration 6 g03400565
(L1) Port "A" - boom secondary (BOOM RAISE) (L2) Port "A" - stick secondary (STICK OUT) (L3) Port "A" - grapple cylinders (GRAPPLE CLOSE) (L4) Port "A" - stick master (STICK OUT) (L5) Port "A" - boom master (BOOM RAISE) (L6) Port "B" - grapple rotate (ROTATE RIGHT) (L7) Port "B" - cab riser cylinders (RISER AFT) (L8) Port "B" - cab riser cylinders (RISER DOWN ) (L9) Port "B" - auxiliary valve (GRAPPLE OPEN) (LSP) Load sense pressure (P1) Pressure port (supply oil from main pumps) (P2) Pressure port (supply oil from main pumps) (PS) Port - pilot pressure (R1) Port "B" - boom secondary (BOOM LOWER) (R2) Port "B" - stick secondary (STICK IN) (R3) Port "B" - grapple cylinders (GRAPPLE OPEN) (R4) Port "B" - stick master (STICK IN) (R5) Port "B" - boom master (BOOM LOWER) (R6) Port "A" - grapple rotate (ROTATE LEFT) (R7) Port "A" - cab riser cylinders (RISER FOR) (R8) Port "A" - cab riser cylinders (RISER UP ) (R9) Port "A" - auxiliary valve (GRAPPLE CLOSE) (T) Return port (plugged) (T1) Return port (to swivel) (T2) Port (plugged) (T4) Port - return oil from hydraulic cooling fan motor (TP) Return port Main Control Valve Components
Inlet Section
The following explanations are for the inlet section of the main control valve. The inlet section of the lower main control valve does not have a main relief valve.Refer to "Lower Main Control Valve Schematic" and "Upper Main Control Valve Schematic" for additional information regarding the inlet section of the main control valve.
Illustration 7 g03591519
Upper main control valve center section (typical example) (P1) Pressure port (supply oil from main pumps) (T1) Return port (to swivel) (49) Main relief valve (50) Load sense relief valve (51) Main control valveMain control valve (51) includes the following components:
Check valve and screen
Load sense relief valve
Main relief valve
Pilot pressure reducing valve
Pilot relief valve
Signal duplication valve (load sense)Pressure oil from the main pumps flows into the main control valve (51) through port (P1) to the inlet section of the main control valve and into the main control valve through port (P2) located on the end section. Refer to "Lower Main Control Valve Ports" and "Upper Main Control Valve Ports" for port locations.Pilot pressure is generated inside the inlet section of the control valve as oil flows to the pilot pressure reducing valve through an internal orifice. The pilot pressure is reduced from pump pressure. Refer to Testing and Adjusting , UENR3552, "Hydraulic System", "Specifications" for the pilot pressure of the machine.The pressure oil then flows to the signal duplication valve for load sense pressure. The load sense pressure is reduced from pump pressure.Pressure oil flows out the main control valve (51) through port (T1) to the hydraulic oil tank.Control Valve Sections
Refer to "Lower Main Control Valve Schematic" and "Upper Main Control Valve Schematic" for additional information regarding the control valve sections.The following explanations are for the control valve section of the main control valve. Some control valve sections may not