325D and 329D Excavators Hydraulic System Check Valve (Return Makeup) - Slow Return Check Valve Caterpillar


Check Valve (Return Makeup) - Slow Return Check Valve
`



Illustration 1g00821055

Main control valve compartment (return circuit)

(5) Makeup line (makeup oil to swing motor)

(10) Main control valve

(17) Slow return check valve

(29) Inlet line to oil cooler (18)




Illustration 2g03258392

Slow return check valve and bypass check valve

(5) Makeup line (makeup oil to swing motor)

(16) Return port (from main control valve)

(17) Slow return check valve

(18) Hydraulic oil cooler

(24) Bypass check valve

(28) Check valve

(29) Inlet line to hydraulic oil cooler

(30) Return line to bypass check valve

(33) Return line (return flow to return filter)

Slow return check valve (17) is contained in check valve (28) . Slow return check valve (17) is located between the main control valve and the hydraulic tank in the return circuit. The slow return check valve restricts the return oil flow. This restriction causes a pressure increase in return port (16) and makeup line (5) .

If cavitation occurs in the swing motor, oil from return port (16) flows into makeup line (5) . This makeup oil is supplied to the inlet port of the swing motor in order to prevent cavitation in the swing motor.

Note: For more information on the makeup operation, refer to System Operation, "Oil Makeup (Swing System)".

The return oil flow through slow return check valve (17) is divided into two flow paths. A portion of the oil flows through inlet line (29) to the hydraulic oil cooler. The cooled oil from the hydraulic oil cooler flows through return line (30) and the return filter to the hydraulic tank. The remainder of the oil flow from slow return check valve (17 ) flows through bypass check valve (24) and the return filter to the hydraulic tank. Bypass check valve (24) is contained in check valve (28) .

Information System:

37-MT, 41-MT, and 42-MT Series Starting Motors Starting Motor Solenoid - Test
325C Excavator Hydraulic System Return Hydraulic System
322C Excavator Hydraulic System Swing Hydraulic System
325C Excavator Hydraulic System Travel Counterbalance Valve
3046 Engine For Caterpillar Built Machines Fuel Shutoff Solenoid - Remove and Install
M313C and M315C Excavators Axle Oil (Rear) - Change
Quick Coupler Wedge Lock(Wheel Loader) Model View Illustrations
W345B Series II Material Handler Hydraulic System Pilot Valve (Joystick)
2001/10/15 Correction to Disassembly and Assembly , "Swing Frame" and Disassembly and Assembly , "Swing Cylinder" {6506}
312C Excavator Machine Systems Blade Cylinder - Install
M316C, M318C and M322C Excavators and M318C and M322C Material Handlers Shipping the Machine
2001/12/24 The New Steering Control Valve Groups Improve Service Life {5051}
325D and 329D Excavators Hydraulic System Bypass Valve (Return) - Bypass Check Valve
312C Excavator Machine Systems Blade - Remove and Install
3126B Engine for Caterpillar Built Machines Throttle Lock Switch Circuit - Test
3046 Engine for Caterpillar Built Machines Water Pump - Test
345B, 345B Series II and W345B Series II Excavators Engine and Pump Control Solenoid Valves
345B, 345B Series II and W345B Series II Excavators Engine and Pump Control Related Components
345B, 345B Series II and W345B Series II Excavators Engine and Pump Control General Information
345B, 345B Series II and W345B Series II Excavators Engine and Pump Control Using Service Mode
345B, 345B Series II and W345B Series II Excavators Engine and Pump Control Parameter Status Checks
345B, 345B Series II and W345B Series II Excavators Engine and Pump Control Using Caterpillar Electronic Technician
345B, 345B Series II and W345B Series II Excavators Engine and Pump Control Troubleshooting Diagnostic Codes
345B, 345B Series II and W345B Series II Excavators Engine and Pump Control General Information (Electrical System)