SERV1855 (345D) _TXT

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TECHNICAL PRESENTATION

345D HYDRAULIC EXCAVATOR

INTRODUCTION

Service Training Meeting Guide

(STMG)

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INTRODUCTION

AUDIENCE

Service personnel who understand the principles of machine systems operation, diagnostic equipment, and testing and adjusting procedures.

CONTENT

This presentation discusses the component locations and systems operation of the 345D

Hydraulic Excavator. Basic engine and machine component locations will be discussed. Also, the implement hydraulics will be covered.

OBJECTIVES

After learning the information in this presentation, the serviceman will be able to: 1. locate and identify the major components in the engine and implement systems; 2. explain the operation of each component in the engine and implement systems; and 3. trace the flow of oil through the implement systems.

REFERENCES

345C Hydraulic Excavator Specalog AEHQ5687

345C Hydraulic Excavator Parts Book SEBP4205

345C Hydraulic Excavator Operation and Maintenance Manual SEBU7861 345C Hydraulic Excavator System Operation (Hydraulic) RENR7324

345C Hydraulic Excavator Testing and Adjusting RENR7325

345C Hydraulic Excavator Specifications Manual RENR7283

345C Hydraulic Excavator System Operation (C11 and C13) RENR9888

345D Hydraulic Excavator Specalog AEHQ5940

345D L Excavator - Parts Manual SEBP5184

345D Excavator - Operation and Maintenance Manual SEBU8300

PREREQUISITES

Interactive Video Course "Fundamentals of Mobile Hydraulics" TEMV9001 Interactive Video Course "Fundamentals of Machine Electronics" TEMV9002

Estimated Time: 10 Hours Visuals: 122 Illustrations Handouts: 54 Pages Form: SERV1855 Date: 04/08

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The 345D is equipped with a C13 ACERT™ engine. The C13 ACERT™ engine utilizes the following technologies: Advanced Diesel Engine Management - Electronic Control Module (ADEM A4), Air-to-Air-Aftercooling (ATAAC), direct injection turbocharged (DI-T), and a Mechanically Actuated Unit Fuel Injector (MEUI) system, which complies with Tier 3 Emissions regulations and European Union Sound IIIA requirements. The engine is rated at 283 kW (380 hp) at 1800 rpm.

The 345D Hydraulic Excavator utilizes a Negative Flow Control (NFC) system for the main implement, hydraulic system. The NFC hydraulic system is a pressure control system that provides proportional control of the main implement pumps in order to provide maximum hydraulic horsepower, controllability, and fuel economy under a wide range of operating conditions.

345D HYDRAULIC EXCAVATOR

INTRODUCTION

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The 345D Hydraulic Excavator incorporates a new monitor panel similar to the 365C Hydraulic Excavator which provides additional operating information to the operator. The machine is designed for improved operator comfort, serviceability, and ease of use.

This presentation discusses the component locations and systems operation of the 345D Hydraulic Excavator.

The 345D Hydraulic Excavator integrates styling and an operator's station similar to the other medium size 300 "D" Series Hydraulic Excavators.

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MACHINE WALKAROUND

From the left side of the machine the following machine components are visible.

- Boom (1)

- Access door behind cab (2)

- Engine access cover (3)

- Stick (4)

- Bucket (5)

- Operator station (6)

- Access door to radiator compartment (7)

- Counterweight (8)

The 345D has an entirely new stick profile. The geometry has been optimized to provide a more cost efficient stick. In other words, the new stick has been designed to have the same reliability and durability of the 345C but is capable of lifting a larger capacity with faster cycle times. 2 1 2 ₃ 4 5 6 7 8

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The compartment behind the operator station includes the following components:

- Machine ECM (1)

- Window washer reservoir (2)

- Master disconnect switch and circuit breakers (3)

- Batteries (4)

- Vandalism guards (5)

- Engine coolant expansion tank (6)

- Secondary fuel filter (7)

- Primary fuel filter and water separator (8)

- Dual element, radial seal air filter (9)

NOTE: Additional attachment ECMs may also be mounted in this compartment.

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The 345D is available with a two-way control pattern change valve (1). The pattern change valve permits changing the operator controls between SAE Excavator and SAE Backhoe

Loader patterns. When changed, this valve redirects pilot oil to the corresponding control spool in the main control valve group.

The pattern change valve is located in the compartment behind the operator's station.

In order to change the pattern, the technician removes the thumbscrew (3) and turns the shift lever (2) to the right 90 degrees to select the alternate position. After the lever is turned, the thumbscrew (3) can be installed into a threaded hole in the new position. The screw prevents unwanted movement of the lever.

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A decal film (arrow) is included to identify the lever position in relation to the operator control pattern.

The decal is located in the same compartment as the pattern change valve.

NOTE: To eliminate operator confusion, if the pattern change valve position is

changed, a plastic card in the operator's compartment must be turned to match the chosen pattern.

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The radiator access compartment is located in front of the counterweight on the left side of the machine. Although the door is hinged, bolts must be removed on the left side to access the components.

This door provides access to assist in cleaning the following components.

- Air to air aftercooler (1)

- Hydraulic oil cooler (2)

- Engine radiator (3)

- Fuel cooler (4)

If the machine is equipped with the optional ether start system (5), it is also located in this compartment. 6 1 2 5 3 4

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The 345D is available with the optional counterweight removal system.

NOTE: The counterweight removal control valve is located in the pump compartment.

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This illustration shows access to the top of the machine from the right side.

The pump compartment access door (1) permits easy access to the hydraulic pumps.

The engine access cover (2) allows access to the engine from the top of the machine.

The machine hydraulic oil reservoir (3) is located between the pump compartment and the diesel fuel tank on the right side of the machine and is accessed from the top of the machine.

The diesel fuel filler cap (4) is accessed from the top of the machine.

The storage compartment (5) is located in the right front of the machine.

The ladder (6) on the front of the machine can be used for access to the top of the machine. 8 1 6 4 5 3 2

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The illustration shows the pump compartment on the right side of the machine. Some of the visible components are:

- Engine oil filter (1)

- Engine oil S•O•S port (2)

- Fan pump (3)

- Main pumps (4)

- Counterweight removal valve (5)

- Auxiliary tool solenoids (6)

- Pilot filter (7)

- Two case drain filters (8). One case drain filter is for the pumps and the other filter is for the motors. 9 1 2 3 7 ₈ 4 5 ₆

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The illustration shows the following main pump components:

- Right pump (1)

- Power shift solenoid and proportional reducing valve (PSPRV) (2)

- Left pump (3) - Suction line (4) - Pilot pump (5) 10 1 2 3 4 5

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The undercarriage of the 345D has undergone improvements and is now offering a couple of attachments. The main change includes the optimization of the track link geometry. By optimizing the geometry, the stress on the track link has been reduced resulting in longer link life and reduced track cracking. There are two undercarriage attachments available on the 345D. A cast idler eliminates the welding design the fabricated one had and reduces tread deformation and early wear. The Positive Pin Retention 2 (PPR2), prevents loosening of the track pin from the track link. Both attachments are ideal for extreme applications or those requiring large amounts of travel.

The 345D has three undercarriage (1) options to meet regional transportation requirements and application needs: the long fixed gauge (L), the long variable gauge (LVG), and the long wide variable gauge (LWVG) undercarriages. The final drives (2) and travel motors are mounted directly to the roller frames in order to drive the tracks. The drive sprockets are bolted to the final drive case. This design keeps the drive sprocket in alignment with the track roller frames and tracks

NOTE: Throughout this training manual, machine travel forward and reverse

directions are determined with the final drives and sprockets behind the operator's compartment.

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OPERATOR'S STATION

The 345D operator's station maintains the improved visibility and operator comfort that the 345C introduced. For operator comfort the cab offers a fully adjustable air suspended seat, with side-to-side shock absorption. Conveniently placed switches, gauges, information display, and controls improve operator comfort, awareness, and efficiency.

The operator's compartment can also be equipped with Falling Object Guard Structure (FOGS) bolted to the top of the compartment.

The monitor continuously monitors all important engine, implement hydraulic, and travel hydraulic functions. The system permits fast troubleshooting, resulting in increased excavator availability and reduced downtime for repairs. The monitor is flashable using Caterpillar Electronic Technician (Cat ET).

The cab improvements include: - new monitoring system - redesigned cab sealing

- redesigned air ventilation system

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The operator's station provides a fully adjustable air suspended seat (1) with new arm rests, which provides maximum operator comfort.

The pattern change card (2) must be switched to display the correct hydraulic control pattern to match the pattern change valve in the compartment behind the cab.

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The left travel control (1) consists of a foot pedal and a hand lever that controls the left travel circuit. When pushed forward, the left track will rotate in the forward direction. When pulled to the rear, the left track will rotate in the reverse direction.

The right travel control (2) consists of a foot pedal and a hand lever that controls the right travel circuit. When pushed forward, the right track will rotate in the forward direction. When pulled to the rear, the right track will rotate in the reverse direction.

When the straight travel pedal (3) is pressed, a common pilot signal is sent to both the left and the right travel spools to shift them equally. This allows the right pump to supply oil to the right travel circuit and the left pump to supply oil to the left travel circuit. Pushing the straight travel pedal does not put the machine into the straight travel mode.

The straight travel mode is controlled hydraulically in the main control valve. Operation of the straight travel mode is explained later in this presentation.

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The 345D Hydraulic Excavator features pilot operated joysticks. The joysticks direct pilot oil to the main control valve in order to actuate various implement functions on the machine.

The left joystick (1) controls the swing and stick functions of the machine.

The right joystick (2) controls the boom and bucket functions of the machine.

NOTE: The 345D is equipped with controls based upon the SAE excavator pattern

from the factory. The pattern change valve (if equipped) can be used to change this pattern to BHL controls if desired.

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Additional components and functions controlled by the switches on each joystick are:

- Blank (1) - Horn (2)

- Medium pressure work tools 2 and 4 (3) - Two-way pump flow work tools 2, 4, and 5 (4) - One-way pump flow work tools 1 and 3 (5) - One touch low idle (6)

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The 345D Hydraulic Excavator incorporates a monitor panel (1), like the small and medium 300D and large 300C excavators, which provides additional operating information to the operator.

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The monitor is a full color Liquid Crystal Display (LCD) graphic display that displays the various parameters of the machine.

- Alert Indicator (1) - illuminates continuously for level 2 warnings.

If one of the following level III critical conditions is logged, the alert indicator blinks ON and OFF.

- Engine oil pressure low - Coolant temperature high - Hydraulic oil temperature high - Clock (2)

- Engine speed dial position indicator (3) - Fuel gauge (4)

- Hydraulic oil temperature gauge (5) - Engine coolant temperature gauge (6) - Machine operating hours (7)

- Work tools (8) 19 1 2 3 4 5 6 7 8

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Under the normal default condition, the monitor screen is divided into the following four areas:

- The clock, engine speed dial position display, and gas station icon are displayed with a green color.

- Three analog type gauges display the fuel level, the hydraulic oil temperature, and the coolant temperature.

- Machine event information is displayed along with the appropriate icon and language. - Multi-information area displays information for operator convenience. The "CAT" logo

mark is displayed when no information is available to display.

The operator or service technician can navigate through the different screens and information about the machine by pushing various buttons on the monitor panel. The buttons are located below the display area of the monitor.

The monitoring system display will display various warnings and information about the condition of the machine. The monitoring system display has three gauges and a number of alert indicators. Each gauge is dedicated to a parameter within a machine system. The monitoring system will allow the user to do the following:

- View system status information - View parameters

- View service intervals - Perform calibrations

- Troubleshoot machine systems

Some of the possible parameters of the machine systems include: the fuel level, the engine coolant temperature, and the hydraulic oil temperature. The gauges receive information from sensors or senders that are connected to the controller. The controller uses the information from each sensor input to calculate the value that is shown on the gauges.

The alert indicators notify the operator of an abnormal condition in a machine system. The controller uses information from pressure switches, sensors, and other inputs in order to determine when an abnormal condition is present. The controller sends a message to the monitoring system display. Then, the monitoring system will display a pop-up alert indicator for the machine system with the abnormal condition.

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The monitor has eight buttons that are used to navigate through the different parameters on the screen. The four directional buttons are: up (1), right (2), down (3), and left (4). The four navigational buttons are: home (8), menu (7), back (5), and OK (6).

The directional buttons navigate the cursor through the various screens.

Pushing the home button changes the monitor screen to the default display. Pushing the menu button changes the default display to the main menu display. Pushing the back button changes the display to show the previous screen that was displayed. Pushing the OK button enters the displayed setting into memory.

NOTE: For more information on the 345D monitor, see monitor package "300D Series

Hydraulic Excavator, 345D Hydraulic Excavator, and 365C and 385C Large Hydraulic Excavator Monitoring System", Form Number SERV7032.

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The hydraulic activation lever (1) has been redesigned for the 345D, however, its purpose is still the same. With the lever in the DOWN position (shown), the hydraulic activation solenoid is in the de-activated position. The lever must be in this position in order to start the machine.

With the hydraulic activation lever in the UP position, the hydraulic activation solenoid is in the activated position. The lever must be in this position before any of the implement controls are able to function.

The ground level, emergency engine shutoff switch (2) is located on the bottom of the seat base.

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Below the operator's seat in the cab is the ground level, emergency engine shutoff switch (arrow).

This switch will shut off the machine without having to climb into the cab. The key start switch must be cycled for the machine to operate again after the emergency shutoff switch is returned to the RUN position.

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The operator functions incorporated into the right side of the operator station are:

- Engine speed dial switch (1)

- Key start switch (2)

- Cigar lighter (3)

- Soft switch panel (4)

- Rocker switches (5)

- HVAC controls (6)

- Radio (7)

NOTE: See the 345D Operation and Maintenance Manual for complete details on all

switches and buttons.

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The soft switch panel is a panel of switches located on the right hand side of the operator's compartment that either turns a function ON/OFF or allows the operator to toggle through different modes of the selected function.

The soft switches provide the operator with the following functions:

Two-speed travel (1): When the button is pushed the travel speed is toggled between the tortoise and rabbit speeds.

- The rabbit indicator indicates automatic speed change. In this setting the travel motors will upstroke and destroke as travel pressure changes in order to allow high speed travel of the machine.

- The tortoise indicator indicates low speed. In this setting, the travel speed will be limited by keeping the travel motors upstroked in order to maximize travel torque.

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Automatic Engine Speed Control (AESC) Switch (2): The AESC function automatically reduces engine speed while there is no hydraulic demand, which reduces noise and fuel consumption.

- The AESC switch disables and enables the AESC function.

- When disabled, the AESC reduces the engine speed by 100 rpm after there has been no hydraulic demand for approximately three seconds. This function occurs at all times, regardless of the switch setting.

- When enabled, the AESC reduces the engine rpm to approximately 1300 rpm after there has been no hydraulic demand for three seconds. When enabled, the LED above the AESC switch is illuminated. In order to deactivate this function, press the switch until the LED is no longer illuminated.

- The second stage AESC delay times and rpms can be changed by using the monitor or Caterpillar Electronic Technician (ET).

Travel alarm cancel (3): The travel alarm cancel switch is a momentary switch. - The travel alarm sounds when travel is detected.

- The travel alarm stops immediately if the travel alarm cancel switch is depressed. - The travel alarm switch is reset every time the travel pressure switch opens.

Work tool switch (4): The work tool switch displays the selected work tool on the monitor display. Press the switch repeatedly in order to change the selected work tool.

Work lights (5): The work lights switch toggles between the different work light combinations. - Pattern 1 - Chassis work lights and cab work lights.

- Pattern 2 - Chassis work lights, cab work lights, and boom work lights.

Upper window wipers (6): The wiper switch toggles between the different modes of the wipers.

- Six second delay. - Three second delay. - Continuous operation. - Off.

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Upper window washer (7): The windshield washer fluid switch is a momentary switch.

- When the switch is pressed, washer fluid will spray from the nozzle. The window wiper will also operate while the switch is depressed. Approximately three seconds after the switch is released, the window wiper will stop.

Heavy lift (8): The heavy lift mode can be selected to boost lifting capability and provide improved controllability of heavy loads.

- When heavy lift is turned ON, the main relief valve increases from 35,000 kPa (5070 psi) to 38,000 kPa (5500 psi), making it possible to operate at the high pressure.

- In heavy lift mode, the maximum engine speed is limited to engine speed dial position 6 (1600 rpm).

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The rocker switches are two-position switches used to turn the functions ON or OFF. The rocker switches provides the operator with the following functions:

Fine swing control (1)

- The top position activates fine swing control. Fine swing control improves the swing control during swing deceleration.

- The bottom position deactivates fine swing control.

Lower window wipers (2)

- The top position activates the wipers. - The bottom position deactivates the wipers.

Lower window washer (3)

- The top position activates the windshield washer fluid. - The bottom position deactivates the windshield washer fluid.

Quick Coupler switch (4)

Seat heater switch (5)

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The back-up switches are located behind the right armrest. The back-up switch (3) toggles between back-up and auto. The back-up switch (2) controls the engine rpm.

In the BACK-UP position, the back-up switch (3) sends a fixed power shift pressure to the pumps. The fixed power shift pressure limits maximum pump output and allows the machine to continue operating in a Derate Mode. Machine productivity will be limited while the machine is in Back-up Mode.

The back-up switch (2) is used to control the engine speed while the Back-up Mode is active. The back-up switch (2) toggles to increase and decrease engine speed. Holding the speed switch in the DOWN position will cause the engine to go to 0 rpm.

The diagnostic connector (1) is located inside of the operators station. It is located behind the right armrest, beside the back-up switches.

The diagnostic connector is used to connect Cat ET to the machine. 26

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ENGINE

The 345D is equipped with a C13 ACERT™ Engine with a rating of 283 kW (380 hp) at 1800 rpm. This represents approximately a 10% increase over the 345C. The C13 ACERT™ incorporates the following state-of-the-art technologies to meet US EPA Tier III regulated emission levels:

- Advanced Diesel Engine Management (ADEM A4) - Air to Air Aftercooler (ATAAC)

- Electronically Actuated Unit Fuel Injection (EUI) System 27

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The fuel system priming switch is located in the compartment behind the cab and above the primary fuel filter. The switch controls the fuel priming pump on the primary fuel filter base.

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The fuel priming pump (1) is located in the primary fuel filter base (3). The secondary fuel filter base (2) contains the fuel system sensors.

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Located on the top of the secondary fuel filter base are the fuel pressure differential switch (1), and the fuel temperature sensor (2).

The fuel filter pressure differential switch (1) monitors the difference between the outlet fuel pressure and the inlet fuel pressure. A fuel pressure difference exceeding 750 kPa (110 psi) will initiate a Level 1 Warning. If repairs are not made after 4 hours, the engine ECM initiates a Level 2 Warning and engine performance is decreased.

The status of the sensors and the filter pressure differential switch may be viewed while using Cat ET.

The Engine ECM uses readings from the fuel temperature sensor (2) to make corrections to the fuel rate and maintain power regardless of fuel temperature (within certain parameters). This feature is called "Fuel Temperature Compensation."

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This illustration shows components on the left side of engine with the counterweight removed.

- The Fuel Transfer Pump (1) is a gear-type pump that pulls fuel from the fuel tank through the primary fuel filter. The fuel then flows through the secondary fuel filter to the

cylinder head.

- The Engine Electronic Control Module (ECM) (2). The engine ECM utilizes the Advanced Diesel Engine Management (ADEM A4) to control the fuel injector solenoid and to monitor fuel injection. The engine ECM is fuel cooled.

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Right Side of Engine

- The Camshaft Speed Timing Sensor (1) determines the No. 1 compression timing prior to the engine starting.

- The Atmospheric Pressure Sensor (2) is an input to the Engine ECM and is used as a reference for air filter restriction. Also, the sensor is used to supply information to the Engine ECM during operation at high altitudes.

- The Intake Manifold Air Pressure Sensor (3) is an input to the Engine ECM to supply information about the air pressure into the intake manifold.

- The Intake Manifold Air Temperature Sensor (4) supplies air temperature data at the air intake manifold to the Engine ECM.

- The Engine Oil pressure Sensor (5) is an input to the Engine ECM to supply an

information warning for low oil pressure. The engine derates for low oil pressure and a logged event code is recorded. The event code can be read by using Cat ET or the monitor. 1 2 3 4 5

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Left Side of Engine

- The Engine Oil Level Sensor (1) is an input to the Engine ECM to supply an information warning for low oil level at start-up.

- The Crankshaft speed timing sensor (2) sends a voltage signal to the Machine ECM in order to determine the engine speed, direction, and timing.

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Front of Engine

- The Engine Coolant Flow Switch (arrow) is mounted in the coolant passage near the engine coolant pump. When the coolant is flowing past the switch the paddle moves and closes the switch contacts. The Engine ECM alerts the operator when there is no coolant flow while the engine is running. An event code is logged when this occurs.

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- The Crankshaft speed timing sensor (arrow) sends a voltage level, signal to the Engine ECM in order to determine the engine speed, direction, and timing.

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HYDRAULIC SYSTEMS

The hydraulic system on the 345D Hydraulic Excavator is operated and controlled by the following five primary systems:

- The main hydraulic system controls the implements, the attachments, the travel circuits, and the swing circuit.

- The pilot hydraulic system supplies oil to the pilot manifold, pilot control valves, swing park brake solenoid valve, two-speed travel solenoid valve, and the power shift pressure reducing valve (PSPRV). The pilot system serves primarily as a hydraulic control system. - The separate hydraulically driven cooling system supplies oil to the fan motor in order to

cool the hydraulic oil, the engine radiator, the air to air after cooler, and a fuel cooler. - The return system directs the return oil from the hydraulic system through the slow

return check valve and the hydraulic oil cooler before it returns to the tank. The case drain oil from the pumps and motors goes through the case drain filters without going through the slow return check valve and the oil cooler before returning to the tank.

Stick

Cylinder _Bucket

Cylinder CylindersBoom

Swing Motor Travel Motors

Pilot Control Valves Priority Valves Main Hydraulic Pumps M Fan Motor _Tank Pilot Manifold

Main Control Valve Group

MAIN HYDRAULIC SYSTEM BLOCK DIAGRAM

Pilot Pump Fan Pump

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This illustration shows the complete hydraulic schematic for the 345D. Both joysticks and travel levers are in the STANDBY position with the engine running and the hydraulic actuation lever in the energized position.

The hydraulic system for the 345D has the following major sub-systems: - fan system

- main hydraulic system

Each system will be discussed in detail later in this presentation.

NOTE: The system will be broken down into sub-systems in the following illustrations

for easier understanding.

P M P PR PL AR3 BR3 BR2AR2 bL3 BL3 AL3 BL4 AL4 bL4 PR aL3 aL1 PL aR1 BL3AL3 BL4 AL4 AR2 BR2 BR3 AR3 bR1 aR1 aL1 bL1 aR2 bR3 bR2 aR3 aL3 bL4 bL3 aR4 bR3 aR4 UP DOWN CLOSE OPEN L R OUT IN

Stick Swing Bucket Boom Travel (L) Travel (R) Boom (2) Stick (1) Swing Travel (L) bR2 Travel (R)

Attch Bucket Boom (1) Stick

(2) Bucket Cylinder CylindersBoom Travel Motor (Right)

Travel Motor (Left)

Swivel Group Swing Motor Swing Motor Stick Cylinder 345D HYDRAULIC SYSTEM BL1 AL1 AL1 BL1 bL1 AL1 BL1 bR1 AR1 BR1 aR3 aR4 aR2 STANDBY

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Power Shift Pressure System

During machine operation, the machine electronic control module (ECM) receives input signals from the following components:

- Engine speed dial

- Engine speed sensor located on the flywheel housing - Right and left pumps pressure sensors

- Engine ECM

The engine and pump controller (ECM) continually monitors all of the input signals. The input signals are processed by the ECM and an output signal is sent to the Power Shift Proportional Reducing Valve (PSPRV). The PSPRV uses the electrical signal from the ECM and pilot pressure to generate the power shift pressure. Equal power shift pressure is directed to each pump control to assist in controlling the output flows from the pumps. Power shift pressure helps regulate pump flow to the maximum allowable hydraulic pump output in relation to engine speed. Engine Speed Sensor Engine ECM Engine and Pump Control Pilot Pump Left Pump Right Pump Proportional Reducing Valve

POWER SHIFT PRESSURE SYSTEM

Monitor

Engine Speed Dial 12:00 10

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Main Hydraulic Pumps

The 345D main hydraulic pump group has two variable displacement piston pumps inside a common housing, in a side-by-side configuration. The pumps are rated at 360 L/min (95 gpm) each. The pumps will be referred to as the right (drive) pump and the left (idler) pump throughout this presentation. The right pump is driven by the engine via an improved flexible coupling. The left pump is driven by the right pump through a gear train. The number of teeth on the gear of the right pump is one tooth less than the gear of the left pump in order to reduce harmonics in the hydraulic system. The difference in rotational speed due to the gearing has no significant impact on the machine performance or flow output. There is an internally mounted centrifugal charge pump.

The pilot pump (1) is mounted on the main hydraulic pump case. The pilot pump draws oil from the pump case and sends it to the pilot filter, then to the pilot system.

The power shift proportional reducing solenoid valve (PSPRV) (2) is mounted on the top and front of the pump case. The PSPRV uses pilot oil as a control signal to the pumps. Power shift pressure can be checked at tap (3).

The pump regulators are mounted on top of the pump case. Each rotating group has its own regulator. The regulators are used to regulate the output flow of the pumps based upon flow demands.

The left pumps each have their own output pressure taps. Pressure sensors for each pump are located directly behind the output pressure taps.

Two case drain filters are located behind the pilot filter. 39

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The output signal from the machine electronic control module to the PSPRV will change when the machine electronic control module detects a change in engine speed. The power shift pressure will change in order to regulate the maximum allowable hydraulic pump output. When the hydraulic pump output is controlled, the desired engine speed is maintained.

When the engine speed increases above the full load setting, due to decreased hydraulic horsepower demand, the power shift pressure will decrease in order to allow more pump flow. A decrease in power shift pressure causes the swashplate to increase its angle, or as it is more commonly known, to upstroke. If both pumps are in operation at the same time, this condition occurs simultaneously in both pumps, and the maximum allowable hydraulic flow output is increased.

If the engine speed decreases below the full load setting due to hydraulic horsepower exceeding engine horsepower, the power shift pressure will increase in order to regulate output to a level that maximizes flow output. As the power shift pressure decreases, the angle of the swashplate in the front pump and rear pump will decrease, or as it is commonly known, will destroke the pump. The maximum allowable hydraulic flow output is optimized to the engine speed.

If flow from only one pump is demanded, the power shift pressure is greatly reduced so the one pump can use full engine horsepower. If flow from both pumps is demanded, the power shift pressure increases so both pumps can be loaded equally.

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Each pump receives four different signals to control the output flow of the pumps:

- Power shift pressure

- System pressure from that pump

- Cross-sensing pressure (from the other pump) - Negative flow control pressure

Power Shift Pressure

The PSPRV receives a control signal from the ECM. The ECM sends an electrical signal to the PSPRV to regulate power shift pressure in relation to the engine speed.

The power shift signal to the pump regulators enable the machine to maintain the target engine speed for maximum productivity.

P

From Pilot Pump From Right NFC Control Orifice

M

To Main Control Valve (Right Side) Right Pump Output Pressure Sensor Power Shift PRV Right Pump Regulator Actuator Left Pump

Left Pump Cross Sensing Signal Right Pump Cross

Sensing Signal

345D PUMP INPUTS

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If the engine and pump control senses that the engine is below the target speed due to a high hydraulic load from the main pumps, the controller will increase the power shift pressure. (The target speed is the speed the ECM reads through the engine speed sensor. The reading is taken 2.5 seconds after the implement/swing and the travel pressure switches open when the joysticks and the travel control pilot controls are returned to NEUTRAL). As power shift pressure increases, the regulators destroke the main pumps accordingly. This reduces the load on the engine, and consequently enables the engine to maintain the target engine speed.

If the engine speed is above the target speed, the ECM will decrease power shift pressure, causing the pumps to upstroke and produce more flow.

Cross-sensing Control

Each pump regulator gets a cross-sensing control from the other pump system pressure.

Negative Flow Control (NFC)

NFC is the primary controlling signal for the main pump output. The NFC signal to the main pump regulator is generated in the main control valve group. The NFC signal is delivered to the left and right pump regulators from the left and right halves of the main control valve group, respectively.

When the joysticks or travel levers are in the NEUTRAL position, the oil flows from the main pumps through the open center bypass passages of the control valves. The oil flows to the valves and returns to the tank by way of the NFC control orifices. The restriction of the NFC orifices causes a pressure signal to be sent to the right and left pump regulators, respectively, as an NFC signal.

When the main pump regulators receive a high NFC signal from the main control valves, the pumps remain at a standby output flow at or near minimum pump displacement.

When a joystick or travel lever is moved from a NEUTRAL position, the open-center passage of the corresponding implement/travel function is closed in proportion to spool movement. This reduces the NFC signal to the main pump regulator and the pump output flow is increased proportionally. When the control valve is fully shifted, then NFC pressure is reduced to slow return check valve pressure.

The use of an NFC hydraulic system maximizes efficiency of the machine by only producing flow from the pumps when the flow is needed.

NOTE: A high NFC signal will always overcomes the horsepower control and decrease

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41

This illustration shows the pumps in STANDBY condition. Each pump regulator senses the Negative Flow Control (NFC) signal, the power shift pressure, the cross sensing pressure, and the system pressure for that pump. The regulator will upstroke or destroke the pumps to maintain the pump flow depending on the conditions the regulator senses.

The regulator controls oil pressure to the right side of the actuator. This controls the angle of the pump swashplate.

The left pump supplies oil to the following valves:

- straight travel valve - left travel control valve - swing control valve - stick I control valve - boom II control valve

- right pump negative flow control valve

P

From Pilot Pump

To Pilot System From Tank

From Left NFC Control Orifice From Right NFC Control Orifice

To Main Control Valve (Right Side)

To Main Control Valve (Left Side) Left Pump Output

Pressure Sensor Right Pump Output Pressure Sensor Power Shift PRV Right Pump Left Pump Pilot Pump Regulator Actuator Actuator Regulator

345D HYDRAULIC PUMPS

STANDBY Destroke M

(51)

The right pump supplies oil to the following valves:

- straight travel valve - right travel control valve

- standard attachment control valve - bucket control valve

- boom I control valve - stick II control valve

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42

Pump Controls

This illustration shows the three separate control sections of the pump control group.

Individual parts are also shown. The three control sections are connected with a series of pins and linkages. The separate control sections work together to regulate pump flow according to demand and hydraulic horsepower requirements. The separate control sections direct system pressure to and from the minimum angle end (large actuator piston) of the servo piston. The servo piston moves the swashplate for increased or decreased pump flow. The lower end of the feedback lever is connected to the servo piston. The feedback lever works as a follow-up linkage to move the horsepower control spool when the servo piston moves.

The negative flow control (NFC) section works in conjunction with the horsepower control section to destroke the swashplate when all hydraulic controls are in NEUTRAL or during implement or travel MODULATION. The torque control section works in conjunction with the horsepower control section to regulate pump flow while the hydraulic circuits are actuated.

Full pump system pressure is directed to the maximum angle (small) servo piston to upstroke the pump. A regulated pressure signal is directed to the minimum angle (large) servo piston to destroke the pump.

Servo Pistons Horsepower Control Sleeve Horsepower Control Spool Torque Control

Piston Feedback Lever

Negative Flow Control Spool Torque

Control Lever

PUMP CONTROL GROUPS

Negative Flow Control

Lever

Torque Control Rod Torque Control Section Horsepower Control Section Maximum Minimum

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43

This illustration shows an end sectional view of the pump controls. The NFC spool is

connected to the lower end of the NFC lever with a pin. The upper end of the NFC lever pivots on a fixed pin in the housing. The torque control rod is connected to the lower end of the torque control lever with a pin. The upper end of the torque control lever pivots on a fixed pin in the housing. The upper end of the feedback lever is connected to the horsepower control spool with a pin. The lower end of the feedback lever is connected to the servo piston.

The feedback lever pin fits tightly into the feedback lever. The feedback lever pin extends into large holes in the torque control lever and the NFC lever. The large holes permit individual control from the torque control lever and the NFC lever. Movement of the servo piston causes the feedback lever to pivot on the feedback lever pin and move the horsepower control spool.

Torque Control Rod Horsepower Control Spool NFC Spool Feedback Lever Servo Piston Swashplate Torque Control Lever Feedback Lever Pin NFC Lever

PUMP CONTROLS

END VIEW

(54)

This illustration shows the components of a pump control group. The NFC spool (1) is

connected to the horsepower control spool (2) by the NFC lever (3), the feedback lever pin and the feedback lever (4). The lower end of the feedback lever is connected to the servo

piston (5). Movement of the servo piston moves the lower end of the feedback lever. The servo piston is also connected to the pump swashplate.

The torque control piston (6) is connected to the feedback lever with the torque control rod (7), the torque control lever (8), and a pin. The NFC lever and the torque control lever operate independently. 44 1 3 2 4 5 6 7 8

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45

This illustration shows the NFC portion of the pump controls. When all hydraulic control valves are in NEUTRAL, a high NFC pressure is directed to the left end of the NFC spool. The NFC pressure pushes the NFC spool to the right against the spring force. The NFC adjusting screw changes the effect of the NFC pressure on the NFC spool. Turning the screw in (clockwise) causes the NFC pressure to increase higher before the NFC spool moves. This condition causes the pump to upstroke sooner (less modulation) when the hydraulic control valve is ACTIVATED.

Turning the screw out (counterclockwise) causes the NFC spool to move at a lower NFC pressure. This condition causes the pump to upstroke later (more modulation) when the hydraulic control valve is ACTIVATED.

In the STANDBY condition, the horsepower control spool directs a signal pressure, which is part of system pressure, to the minimum angle end of the servo piston. The increase in pressure moves the servo piston to the right against the minimum angle stop screw. The pump flow will remain constant until the NFC pressure from the control valve decreases.

PUMP CONTROLS

STANDBY NFC Spool Servo Piston Horsepower Control Spool From NFC Orifice NFC Adjustment Screw Minimum Angle Stop NFC PressureNFC Pressure

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46

This illustration shows the pump controls at the beginning of an upstroke that was caused by a decrease in NFC pressure. When a hydraulic control valve in the main control valve is shifted, the NFC pressure is decreased. Due to reduced NFC pressure, spring force moves the NFC piston to the left. The NFC piston moves the lower end of the NFC lever to the left with the pin on the upper end of the NFC lever as the pivot point.

As the lower end of the NFC lever moves to the left, the large hole through the lever also moves to the left. As the large hole moves to the left, spring force pulls the horsepower control spool and the upper end of the feedback lever to the left because the feedback lever pin is allowed to move to the left.

The minimum angle servo piston is opened to case drain through the right orifice in the

horsepower control sleeve and the right end of the horsepower control spool. System pressure pushes the maximum angle servo piston to the left to upstroke the pump.

NFC Piston

Maximum Angle End of Servo Piston Minimum Angle End

of Servo Piston

Horsepower Control Spool Horsepower

Control Sleeve Feedback Lever Pin

NFC Lever Feedback Lever Maximum Angle Stop

PUMP CONTROLS

FLOW INCREASE NFC Pressure From NFC Orifice

(57)

As the servo piston moves, the lower end of the feedback lever moves to the left. The feedback lever rotates clockwise with the feedback lever pin as the pivot point. The upper end of the feedback lever pulls the horsepower control spool to the right until the right land on the horsepower control spool reaches a balance point between the orifices through the horsepower control sleeve. Flow to and from the minimum angle piston is metered by the horsepower control spool and the horsepower control sleeve. The swashplate angle remains constant until the NFC pressure is again changed.

The amount of reduction in NFC signal pressure determines the amount of pump upstroke. If NFC pressure is reduced to minimum, the pump will upstroke until the servo piston contacts the maximum angle stop screw.

A decrease in power shift pressure will cause an increase in flow from the pump in the same manner as described for a decrease in system pressure, since both power shift pressure and system pressures act on the torque control piston.

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47

Pump Flow Decrease - Due To Increased Pump Load

This illustration shows the torque control piston and horsepower control spool with the pump in the upstroked position at the beginning of DESTROKE. For the purpose of this presentation, it is assumed that power shift pressure remains constant.

- Power shift pressure from the PRV enters the pump controls and pushes on the plug at the left end of the torque control piston.

- System pressure from this pump enters the pump controls and goes to the right shoulder area on the torque control piston.

- The cross-sensing signal pressure from the other pump goes to the left shoulder area on the torque control piston.

- The combination of power shift pressure and the two system pressures push the torque control piston to the right against the force of the horsepower control adjustment spring. - The horsepower control spool directs the signal pressure to the minimum angle end of the

servo piston to destroke the hydraulic pump.

PUMP CONTROLS

FLOW DECREASE - BEGINNING OF DESTROKE

Horsepower Control Spool Power Shift Pressure Torque Control Piston

Minimum Angle End of Servo Piston

Maximum Angle End of Servo Piston

Horsepower Adjustment

Screws Feedback Lever Pin Torque Control Lever

Torque Control Rod Horsepower Control Spring

Cross-sensing Signal From Other Pump

From Power Shift Solenoid

(59)

The large horsepower adjustment screw regulates the pressure or point that the pump starts to destroke (large spring adjustment). The small adjustment screw regulates the rate that the pump destrokes (small spring adjustment).

The following occurs when the system pressures and power shift pressure push the torque control piston to the right:

- The torque control rod moves to the right to compress the horsepower control springs. - The torque control rod moves the lower end of the torque control lever to the right with

the fixed pin on the upper end of the torque control lever as the pivot point.

- The torque control lever pulls the feedback lever pin and the upper end of the feed back lever to the right.

- The feedback lever pulls the horsepower control spool to the right against the spring force.

- System pressure is directed around the horsepower control spool through the center orifice of the horsepower control sleeve and to the minimum angle end of the servo piston.

- The increase in pressure in the minimum angle piston moves the servo piston to destroke the pump.

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48

This illustration shows the pump controls at the end of DESTROKE. When the servo piston moves toward minimum angle, the lower end of the feedback lever moves to the right turning the lever counterclockwise with the feedback lever pin as the pivot point. The lever movement shifts the horsepower control spool to the left so system pressure is metered through the two orifices to and from the minimum angle end of the servo piston. Pump flow is held constant until one of the signal pressures changes.

An increase in power shift pressure will cause a decrease in flow from the pump in the same manner as described for an increase in system pressure since both the power shift pressure and system pressure act on the torque control piston.

PUMP CONTROLS

FLOW DECREASE END OF DESTROKE

Orifices Horsepower

Control Spool

Maximum Angle End of Servo Piston Feedback

Lever Pin

Feedback Lever

Minimum Angle End of Servo Piston

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49

Pilot Hydraulic System

The pilot hydraulic system receives oil from the pilot pump. Oil from the pilot pump is sent to the pilot manifold and then to the pilot control valves, which are actuated by the joysticks in the operator's compartment, for machine operation (implement operation, swing operation, and travel operation). The pilot control valves control the pilot oil pressure to the individual spools in the main control valve. When the main control valve spools shift, supply oil from the main pump is sent to the corresponding cylinders and motors.

Stick

Cylinder _Bucket

Cylinder CylindersBoom

Swing Motor Travel Motors

Pilot Control Valves Priority Valves Main Hydraulic Pumps M Fan Motor _Tank Pilot Manifold

Main Control Valve Group

PILOT SYSTEM BLOCK DIAGRAM

Pilot Pump Fan Pump

(62)

The pilot pump (1) is a gear-type pump that supplies oil flow to the pilot system. The pilot pump is mechanically connected to the left main pump.

50

(63)

The pilot hydraulic oil filter (4) is located in the pump compartment on the right rear side of the machine. The oil filter is a spin-on type filter.

Oil flows from the pilot pump, through the filter, to the pilot manifold, the power shift pressure reducing valve, and the pilot accumulator. The filter element removes the contaminants from the pilot oil.

Contaminated oil or cold oil may cause the oil flow through the filter element to become restricted. If the oil flow through the filter element does become restricted, the oil bypasses the filter element through the bypass valve.

Pilot system pressure can be checked at pressure tap (3). Pilot system pressure can be adjusted at pilot relief valve (1).

The blue dust cap (2) is where the hydraulic system S•O•S can be sampled. 51

1

2 3

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52

The pilot relief valve limits the pilot pressure in the pilot system. When the pressure in the pilot system reaches the pressure setting of the pilot relief valve, part of the pilot oil flow is returned to the hydraulic tank. The pilot relief valve is adjustable.

To Tank

From Pilot Pump

(65)

The hydraulic pilot oil manifold is accessible by removing the cover plate located under the machine, behind the swing bearing. The hydraulic pilot oil manifold consists of the following components:

- Hydraulic oil pilot manifold (1)

- Hydraulic activation solenoid valve (2)

- Swing parking brake solenoid (3)

- Two-speed travel solenoid (4)

The hydraulic activation valve is not visible but is located between the hydraulic activation solenoid valve and the swing brake solenoid. The hydraulic pilot oil accumulator is located on the top of the mounting bracket for the pilot oil manifold.

53

2

3

4 1

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54

Hydraulic Activation Control Lever

The hydraulic activation control lever is located on the left side of the operator's seat. Mounted to a bracket with the hydraulic activation control lever is the limit switch and plunger. The limit switch is activated by the hydraulic activation control lever. The limit switch activates the neutral start relay and allows the machine to be started when in the locked position. Without the hydraulic activation control lever in the locked position the machine cannot be started.

After the machine has been started the hydraulic activation control lever must be put into the unlock position in order to supply pilot oil to the pilot control valves.

HYDRAULIC

ACTIVATION LEVER

Limit Switch Plunger

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55

When the hydraulic activation control lever is shifted to the LOCKED position, the hydraulic activation solenoid valve located in the pilot manifold is DE-ENERGIZED. Spring force pushes the hydraulic solenoid up, blocking pilot oil and causing the top side of the hydraulic activation valve to be open to drain. Spring force pushes the hydraulic activation valve up, causing the pilot joystick to be open to drain. Because there is no pilot pressure available at the pilot control valves, the spools cannot be shifted in the main control valve.

Pilot Manifold To Travel Motors To Tank From Hydraulic Activation Valve From Pilot Pump To Pressure Reducing Valve From Pilot Pump To Heavy

Lift Circuit Control ValveFrom Main To Pilot

Control Valves

Hydraulic Activation Solenoid Valve HYDRAULIC ACTIVATION SOLENOID VALVE

LOCKED

Hydraulic Activation

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56

When the hydraulic activation control lever is shifted to the UNLOCKED position, the

hydraulic activation solenoid valve located in the pilot manifold is ENERGIZED. Because the solenoid valve is now open, pilot oil flows to the hydraulic activation valve. The hydraulic valve pushes downward against the spring opening a passage which enables pilot oil to flow through the hydraulic valve and to the pilot control valves.

Hydraulic Activation Valve Pilot Manifold To Travel Motors To Tank To Hydraulic Activation Valve From Pilot Pump To Pressure Reducing Valve From Pilot Pump To Heavy

Lift Circuit Control ValveFrom Main To Pilot

Control Valves

Hydraulic Activation Solenoid Valve HYDRAULIC ACTIVATION SOLENOID VALVE

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57

Pilot oil flows from the pilot manifold to the swing parking brake solenoid valve. When the implement controls and/or swing control levers are operated, the increase in pilot oil pressure causes the swing/implement pressure switch to close. The swing/implement pressure switch is an input to the ECM. The ECM then signals the swing brake solenoid to actuate. Pilot oil then flows through the solenoid valve to the swing parking brake located in each swing motor. This oil releases the swing parking brakes.

To Travel Motors To Pressure Reducing Valve From Pilot

Pump Lift CircuitTo Heavy Control ValveFrom Main To

Pilot Control Valves

SWING BRAKE ACTIVATION SOLENOID

UNLOCKED To Swing Parking Brake Pilot Manifold Swing Brake Activation Solenoid

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58

Two-Speed Travel Solenoid

When the switch for two-speed travel speed is set in the AUTO position, the ECM

energizes the two-speed travel speed solenoid valve. With the travel speed solenoid valve energized, a path opens for pilot oil to flow to the displacement change valve in the right travel motor and left travel motor. As the displacement change valve operates, the travel speed is maintained at the HIGH SPEED position. In this position, the pressure sensor for main pump delivery pressure controls the travel speed in accordance with the travel load. For example, low speed during a high load, high pump output pressure condition, and high speed during a low load and low pump output pressure condition.

To Travel Motors To Pressure Reducing Valve From Pilot

Pump Lift CircuitTo Heavy Control ValveFrom Main To

Pilot Control

Valves _ManifoldPilot

Two-Speed Travel Solenoid

TWO-SPEED TRAVEL SOLENOID

(71)

The hydraulic pilot oil accumulator (arrow) stores pilot pressure for use at the main control valve. During multiple implement, swing, and travel operations, the pilot system needs more oil to operate smoothly. The pilot oil accumulator provides additional pilot oil to the pilot system when the pilot pump flow is inadequate.

In the accumulator, an internal bladder is filled with nitrogen gas. When pilot oil enters the accumulator, it acts against the nitrogen gas filled bladder compressing it. There is a check valve located inside the hydraulic pilot oil manifold that prevents a backflow of the stored oil in the accumulator.

The stored hydraulic pressure in the accumulator can also be used to lower the boom and/or stick if the engine is stopped. See the Operation and Maintenance Manual for the correct procedures to lower the boom with a stopped engine.

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60

Pilot Logic Network

The pilot logic network consists of two individual flow paths. An orifice in each flow path allows a small amount of pilot oil flow to enter the paths. Down stream of one orifice, the flow goes through both travel control valves, only, before returning to the tank. Down stream of the other orifice, the flow goes through each implement and swing control valve before returning to the tank. The orifices maintain pilot pressure upstream and limit the amount of flow through them.

When one or more travel controls are activated, the open-center oil path to tank is blocked. With no open flow path to tank, pressure increases in that part of the pilot logic network. The increase in pressure closes the travel pressure switch to signal the ECM to activate the AESC to increase engine speed.

When one or more implement or swing control valves are activated, the open-center oil path through the other orifice to tanks is blocked. With no open flow path to tank, pressure increases in that part of the pilot logic network. The increase in pressure closes the swing/implement pressure switch to signal the ECM to activate the AESC to increase engine speed. The ECM also activates the swing park brake solenoid to release the swing park brake. The swing park brake is not released when only the travel circuits are activated.

Boom (1) Stick (1) Swing Travel (L) Travel (R) Attch Bucket From Pilot Manifold From Left Pump From Right Pump To Boom (2) To Stick (2) Implement Swing Pressure Switch Travel Pressure Switch

345D PILOT HYDRAULIC SYSTEM

PILOT LOGIC NETWORK

Main Control valve Pilot

Logic Network

(73)

Boom (1) Stick (1) Swing Travel (L) Travel (R) Attch Bucket From Pilot Manifold From Left Pump From Right Pump To Boom (2) To Stick (2) Implement Swing Pressure Switch Travel Pressure Switch

345D PILOT HYDRAULIC SYSTEM

STRAIGHT TRAVEL MODE

Main Control valve

Pilot Logic Network

61

Straight Travel Mode

When both travel circuits and at least one implement or swing control valve are activated at the same time, the machine goes into the straight travel mode. Pilot pressure in the pilot logic network, downstream of the implement/swing orifice, goes through the left travel control valve and the right travel control valve and is directed to the top of the straight travel valve. The pilot pressure pushes the straight travel valve down. The machine goes into the straight travel mode.

In the straight travel mode, the right pump flow is directed to the right travel control valve. The right pump flow also goes through the upper portion of the straight travel valve to the left travel control valve. The left pump flow goes through the left side parallel feeder path to the swing and stick control valve. The left pump flow also goes through the straight travel control valve and into the right side parallel feeder path to the attachment, bucket, and boom control valves.

A check valve and orifice inside the straight travel valve will let some of the left pump flow into the travel circuits if the right pump system pressure is higher than the travel pressure. The check valve prevents any right pump flow from going to the implement/swing circuits.

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62

Pilot Control Valve

The individual pilot control valves in the main pilot control valves are pressure reducing valves. When the joystick is moved, the metering spring pushes the spool down. Pilot oil from the pilot supply port flows around the spool to port (B). The same pressure flows through the center of the spool to the lower end of the spool. As pressure increases, the spool moves up to compress the metering spring. The pilot pressure and flow are metered by the spool until the joystick is moved farther.

When either joystick is operated, the pilot control valve sends pilot pump oil through the pilot lines to the pilot ports at the main control valve in order to shift the spools of the main control valve. This enables the implement operations or swing operation. Return pilot oil from the main control valve returns through the return port of the pilot control valve and is allowed to flow back to the hydraulic tank.

Joystick Rod Return Spring Seat Return Chamber A A Section A-A Plate Supply Pilot Oil Port A Port B Metering Spring Return to Pilot Manifold Supply Pilot Oil

From Pilot Manifold

Port A Port B

Spool

(75)

The amount of pilot oil pressure that flows from the pilot control valve to the main control valve directly corresponds with the position of the joystick. When the joystick is moved slightly from the NEUTRAL position, low pilot oil pressure is sent to the spool of the main control valve. The main control valve shifts a slight amount. The volume of oil delivery to the cylinders and/or motors is small. The speed of the cylinders and/or motors is slow. As the joystick is moved farther from the NEUTRAL position, the pilot oil pressure that is sent to the main control valve increases. The spool in the main control valve shifts farther and the speed of the cylinders and/or motors increases. Thus, cylinder speed and motor speed is controlled by the amount of movement and the position of the joystick.

SERV1855 (345D) _TXT

TECHNICAL PRESENTATION

345D HYDRAULIC EXCAVATOR

INTRODUCTION

Service Training Meeting Guide

(STMG)

INTRODUCTION

AUDIENCE

CONTENT

OBJECTIVES

REFERENCES

PREREQUISITES

TABLE OF CONTENTS

345D HYDRAULIC EXCAVATOR

INTRODUCTION

POWER SHIFT PRESSURE SYSTEM

345D PUMP INPUTS

345D HYDRAULIC PUMPS

PUMP CONTROLS

END VIEW

PUMP CONTROLS

PUMP CONTROLS

PUMP CONTROLS

HYDRAULIC

ACTIVATION LEVER

SWING BRAKE ACTIVATION SOLENOID

TWO-SPEED TRAVEL SOLENOID

345D PILOT HYDRAULIC SYSTEM

345D PILOT HYDRAULIC SYSTEM