Ground Force Equipment GX70D PRO

Operator & Maintenance Manual

Keep this manual with the machine. Read and understand it before operation or service.

Preface

This manual provides instructions for the correct operation and maintenance of the machine. Keep it with the machine at all times. If it is damaged or lost, obtain a replacement from Ground Force Equipment or an authorized dealer.

Warning

Do not operate, inspect, maintain, or repair this machine until you have carefully read and fully understood this manual. Correct operating and maintenance procedures are essential to the machine's safety, reliability, and performance.

Read every CAUTION, WARNING, and DANGER notice. Failure to follow these instructions can cause unsafe conditions, machine damage, serious injury, or death.

This manual covers machines supplied to multiple markets. Optional equipment described here may not be installed on your machine. Ground Force Equipment may revise product specifications, design, operating instructions, and maintenance information without prior notice.

Safety Rules

Operate, inspect, and maintain the machine in accordance with all applicable laws, regulations, and jobsite requirements. The safety information in this manual supplements those requirements; it does not replace them.

Only trained and qualified personnel may operate the excavator. Keep every warning label clean, legible, and securely attached. Understand the machine's controls, operating limits, working radius, and installed control pattern before use.

Contents

1. Introduction

• Overview
• Information and Warning Labels
• Repair and Maintenance
• Instruments and Controls
• Safety-Lock System
• Operator's Seat and Seat Belt

1. Operating Instructions

• Safety and Responsibility
• Transportation and Lifting
• Bucket Replacement
• Starting, Operating, and Parking
• Bucket Work and Mud Recovery
• Optional Components

1. Maintenance

• Preventive Measures
• Battery and Electrical System
• Engine, Fuel, Air, and Cooling Systems
• Hydraulic System and Swing Drive
• Greasing, Track Tension, and Lubrication

1. Introduction

Intended Use

The uses described in this manual assume normal operating conditions. If the machine will be used for another purpose or in a hazardous environment - including areas containing flammable or explosive material or asbestos dust - follow all special regulations and equip the machine for that use. Contact Ground Force Equipment or an authorized dealer for guidance.

Machine and Engine Identification

Specifications can vary by serial number, market, attachment, and machine configuration. Verify the machine and engine identification plates before ordering parts, selecting fluids, or applying model-specific service data.

Electrical and Hydraulic Systems

The electrical system includes engine starting and charging, machine monitoring, engine and pump controls, and air-conditioning circuits where equipped. The automatic-idle system reduces engine speed after the controls remain inactive for approximately five seconds and returns the engine to the selected speed when an operating command is detected.

The hydraulic-pump assembly consists of two fixed-displacement gear pumps driven by the engine. The main control valve directs flow to the boom, arm, bucket, swing, travel, blade, and auxiliary circuits. Travel and swing motors are designed to provide high torque and withstand the radial loads created during machine operation.

Warning Labels

• **Swing area:** Keep all personnel outside the upper structure's swing radius.
• **Hot coolant:** Allow the cooling system to cool before opening the radiator cap.
• **Slip hazard:** Use designated steps and handholds only.
• **Travel direction:** Confirm the blade and drive-sprocket positions before moving the travel controls.
• **Working area:** Keep personnel clear of the boom, arm, bucket, attachment, blade, tracks, and counterweight.
• **Fuel:** Stop the engine and keep flames, sparks, and smoking materials away while refueling.

Before leaving the operator's seat, lower the work equipment, engage the safety lock, stop the engine, and remove the key. Never allow anyone beneath unsupported equipment. When adjusting track tension, loosen the grease-relief valve slowly and no more than one turn.

After a hydraulic cylinder has been removed and reinstalled, purge trapped air at low idle. Slowly extend and retract the cylinder four or five times while stopping approximately 100 mm before each end of stroke, then move it slowly through its full stroke three or four times.

Repair and Maintenance

Correct preventive maintenance reduces cost, improves reliability, and extends machine life. Published intervals assume normal conditions; severe service requires shorter intervals. Operator maintenance may be performed only by trained personnel. Repairs outside the operator's training must be completed by Ground Force Equipment, an authorized dealer, or a qualified service facility.

Keep complete inspection and service records. Inspect fuel hoses for aging, cracking, blistering, abrasion, loose clamps, and leakage. Inspect the fuel tank for water, sediment, damage, insecure mounting, and leaks.

Use clean diesel fuel that meets the installed engine's requirements. The source specification identifies ASTM D975 No. 1-D or No. 2-D, a cetane number of at least 42, and sulfur content no greater than 0.5% by weight. Follow any stricter requirement on the engine emissions label or required by law.

Instruments and Monitor

Do not operate the machine until you understand every gauge, indicator, switch, and control. Depending on configuration, the monitor displays operating hours, engine speed, system voltage, coolant temperature, fuel level, hydraulic-oil temperature, engine-oil pressure status, and engine fault codes.

• **Coolant temperature:** The source monitor specification identifies approximately 40-102 C (104-216 F) as the normal displayed range. Above 102 C, stop work, reduce speed to low idle, and inspect the cooling system.
• **Hydraulic-oil temperature:** If oil temperature exceeds 85 C (185 F), stop work, idle the engine, and inspect the hydraulic system and oil level.
• **Low oil pressure:** Stop the machine and shut down the engine immediately.
• **Low fuel:** Refuel in a safe location using the correct fuel.

When the start switch is turned to ON, the monitor should complete an approximately five-second self-test. Allow the self-test to finish before starting. A function marked optional may not be installed on every machine.

Operator Controls

The left joystick controls arm movement and upper-structure swing. The right joystick controls the boom and bucket. A top joystick button may control boom offset where equipped. Always follow the control-pattern label installed on the machine.

Do not rest a foot on a travel pedal. Before traveling, identify the drive sprocket and blade positions. Travel response reverses when the drive sprockets are toward the front. Move both controls together for straight travel, one farther than the other for steering, and opposite directions for counter-rotation only when conditions allow.

Use the auxiliary pedal only with an approved attachment and after confirming correct hydraulic flow, pressure, and hose connection.

Safety-Lock System

Place the safety-lock lever in the locked position before starting, entering or leaving the station, or whenever controls must be disabled.

• **Position A - Locked:** Work equipment, swing, travel, and auxiliary controls are disabled. The engine can be started only in this position.
• **Position B - Unlocked:** Controls are enabled for operation and the engine-start circuit is disabled.

Do not operate the machine if any control remains active while the lever is locked.

Operator's Seat and Seat Belt

The operator's station is designed for one person. Do not adjust the seat during excavation or travel. Lock the fore-and-aft adjustment securely before operation.

Inspect the belt and mounting hardware before each work period. Replace it if cut, frayed, stretched, damaged, deformed, or loaded during an accident. Clean with mild soap and water, allow it to dry fully extended, and never modify the belt or mounting hardware. Replace the complete assembly at least every two years.

2. Operating Instructions

Break-In Period

Operate cautiously during the first 50 hours. Avoid overloads, abrupt control movement, and continuous maximum-power operation. Check hydraulic-oil pressure and temperature regularly. Replace the engine oil and oil filter after the first 50 hours unless the installed engine's instructions require an earlier service.

Engine Cooling and Lubrication

The cooling system uses a radiator, water pump, fan, thermostat, coolant passages, and temperature sensor. Keep the radiator clean, maintain airflow, inspect mounts and hoses, and prevent hot discharge air from recirculating into the radiator intake.

Never remove the radiator cap while hot. Allow the system to cool, cover the cap with a heavy cloth, and open it slowly.

Engine oil reduces friction, carries heat, supports sealing, controls deposits, and protects internal surfaces. Use the API category and SAE viscosity specified for the installed engine. If the low-oil-pressure warning appears, stop and shut down immediately.

Use the maintenance schedule for the Yanmar 3TNV74F engine identified on the machine. If this manual and the installed engine manual differ, follow the stricter safety requirement and obtain qualified service guidance.

Hydraulic Service Intervals

• Replace return, suction, and pilot hydraulic filters after the first 250 hours.
• Thereafter, replace return and suction filters every 500 hours.
• Replace the pilot filter every 1,000 hours.
• Replace swing- and travel-reduction oil after the first 500 hours.
• Thereafter, replace swing-reduction oil every 1,000 hours and travel-reduction oil every 2,000 hours.

Shorten intervals for breaker work, dust, contamination, or extreme temperatures.

Safety and Responsibility

The operator must inspect the machine, understand work-area hazards, report damage affecting safety, and prevent personnel from entering the operating area. No one may approach from behind, enter a blind area, or stand within the swing or travel path without the operator's acknowledgment.

Travel Precautions

For level travel, retract the work equipment and keep it approximately 40-50 cm (16-20 in.) above the ground. Avoid obstacles. If one must be crossed, raise the blade, reduce speed, and cross near the center of the tracks. Avoid lateral tilt greater than 10 degrees.

On slopes of 15 degrees or more, use the illustrated machine position, keep the attachment low enough to lower quickly, travel slowly, and avoid sudden movement. Do not turn across a slope.

Maintain at least the following source-manual electrical clearances unless regulations or the utility require more:

Prohibited Operating Practices

• Do not strike rocks or curbs with the blade.
• Prevent the bucket and boom cylinder from contacting the blade.
• Do not support the machine only on the outer ends of the blade.
• Do not use swing force to compact soil or force bucket teeth through the ground.
• Do not use travel force to dig with the bucket embedded.
• Do not hold a hydraulic cylinder against the end of its stroke.

Transportation

Comply with all legal limits for transport weight, width, height, and length. Choose a firm, level loading area away from shoulders and curbs. Remove mud, oil, ice, and debris from the trailer, ramps, and tracks.

1. Apply the transport vehicle's parking brake and chock its wheels.
2. Secure ramps of adequate width and capacity to the trailer.
3. Keep the ramp angle at 15 degrees or less and make both ramps level with each other.
4. Select low travel speed and disable automatic idle.
5. Align the machine with the ramps and travel slowly. Do not turn on a ramp.
6. Prevent the bucket-cylinder rod and attachment from striking the trailer.
7. Once loaded, lower the attachment, engage the safety lock, stop the engine, remove the key, turn off the battery disconnect, and secure all doors and covers.
8. Block both ends of the tracks and use rated chains or tie-downs at the designated points.

If hydraulic lines must be disconnected, allow the machine to cool and release stored pressure first. Lower the attachment securely, stop the engine, leave the key switch ON without starting, move all controls through every direction several times, turn the key OFF, release tank pressure slowly, and contain all fluid. Protect hoses and fittings from contamination.

Lifting the Machine

Never lift the machine with anyone in the cab or on the machine. Use only designated lifting points and approved lifting equipment rated for the machine's complete operating weight. Keep all personnel away from the suspended load.

Bucket Replacement

Removal

Wear eye protection, a hard hat, and gloves. Support the bucket so it cannot roll or fall. Lower it to firm ground, remove retaining hardware, and drive out the connection pins using the approved procedure. Flying metal fragments can cause serious injury.

Installation

Never place fingers inside a pin bore to check alignment. Align the arm and linkage with the bucket, apply the specified grease, install the pins, and secure the retaining bolts and double nuts. Grease all joints and confirm free movement before use.

Before Operation

• Correct every safety-related defect before starting.
• Provide adequate ventilation indoors; exhaust gas can kill.
• Start only while seated with the belt fastened.
• Keep the cab door secured during operation.
• Do not operate while impaired by alcohol, drugs, medication, illness, or fatigue.
• Face the machine and maintain three points of contact when entering or leaving. Never jump.
• Keep hands away from door, cover, window, and linkage pinch points.
• Wear suitable clothing, footwear, eye protection, and a hard hat.
• Never overload the machine.

Before starting, inspect the machine, complete routine maintenance, adjust and lock the seat, check all controls and instruments, test lights and wipers, inspect for leakage and loose parts, confirm the fuel level, and secure the engine hood. Bleed the fuel system if it ran dry or air entered the lines. Sound the horn and make sure the area is clear.

Start Switch and Starting

The start switch has OFF, PREHEAT, and START positions. Follow the installed engine's preheat indicator and starting instructions. The source manual specifies up to one minute of preheating and limits each starter engagement to 20 seconds, followed by a two-minute cooling period before another attempt.

Do not touch controls while starting. If abnormal noise, vibration, smoke, or another unsafe condition occurs, turn the key OFF immediately. Below -15 C (5 F), allow the engine and hydraulic system to warm at low idle for approximately 10-15 minutes before heavy work.

Machine Operation

Move all controls slowly until machine response is confirmed. The left joystick controls arm movement and swing; the right joystick controls boom and bucket movement. Follow the installed control-pattern label rather than relying only on a generic diagram.

Before traveling, identify the drive-sprocket position. When the sprockets are at the rear, push both travel controls forward for forward travel and pull them rearward for reverse. When the sprockets are at the front, control response is reversed. Use unequal control movement for gradual steering and opposite directions for counter-rotation. Do not reverse direction abruptly.

Shutdown and Parking

Park on firm, level ground whenever possible. Return travel controls to neutral, reduce the engine to low idle, lower the bucket flat to the ground, engage the safety lock, and allow the engine to idle for several minutes before turning the key OFF. Remove the key and disconnect battery power when required.

If slope parking is unavoidable, orient the machine safely, lower the attachment and blade, and block both tracks. Close and lock the cab, windows, covers, and compartments.

For extended storage, clean the machine, inspect for leakage or damage, lubricate all points, protect exposed metal from corrosion, service fluids as specified, and follow the engine and battery storage procedures.

Bucket Work

Use smooth strokes and avoid cylinder end stops. Digging force and efficiency are generally greatest when linkage angles are near 90 degrees. For trenching, align the tracks with the trench and excavate the sides before the center when cutting a wide trench.

Position trucks where the operator has clear visibility. Load over the rear or designated side only when ground conditions, clearance, and machine stability allow it.

Never use swing force to rake, demolish, or force bucket teeth into the ground. Do not use travel force for excavation or drop the boom and bucket as a breaker or pile driver. Use an approved hydraulic breaker for impact work. Do not use the excavator as a crane unless it is specifically equipped, rated, and operated under an approved lifting procedure.

Recovery from Mud

Use extreme caution on soft ground. If one track is stuck, use the flat bottom of the bucket to raise it only enough to place suitable blocking beneath the track. If both tracks are stuck, place suitable mats or boards, use a digging motion to assist travel, and avoid sudden movement.

Keep the angle between boom and arm approximately 90-100 degrees while supporting the machine. Never support the machine on bucket teeth. After water or mud operation, grease the work-equipment pins and inspect undercarriage and reduction-gear lubricants for contamination.

Hydraulic Breaker

Use only an approved breaker matched to the machine's hydraulic flow, pressure, and weight limits. Keep the tool perpendicular to the work and firmly seated. Do not raise the machine more than necessary to maintain tool contact.

• Keep at least 5 cm (2 in.) of cylinder travel from the end of stroke.
• Do not swing the breaker into material.
• Do not move or twist the tool during impact.
• Do not strike horizontally or upward.
• Do not use the breaker as a pry bar.
• Stop if hoses vibrate abnormally, leakage appears, or the attachment behaves unexpectedly.

3. Maintenance

Before maintenance, park on firm, level ground, lower the attachment, stop the engine, remove the key, engage the safety lock, release stored pressure, allow the machine to cool, and attach a clearly visible DO NOT OPERATE tag. Hot fluids, pressurized systems, and hot components can cause severe injury.

Battery

Batteries produce explosive gas and contain corrosive sulfuric acid. Keep flames and sparks away, provide ventilation, and wear eye and skin protection. Disconnect the negative cable first and reconnect it last. Never place tools or metal objects across battery terminals.

If electrolyte contacts skin, flush immediately with clean water. If it enters the eyes, flush continuously for at least 15 minutes and obtain immediate medical treatment. Charge only with an approved charger set for the battery type and voltage. Dispose of batteries according to environmental regulations.

Air Conditioning

The installed air-conditioning system uses R134a refrigerant where identified by its service label. Refrigerant is pressurized and can cause frostbite or eye injury. Do not loosen fittings or intentionally release refrigerant. Service must be performed by qualified personnel using approved recovery and charging equipment.

Keep the condenser and cab-air filter clean. Inspect hoses, belts, electrical connections, and compressor mounting. Do not operate the system if refrigerant leakage, damaged hoses, unusual noise, or compressor seizure is suspected.

Engine and Fuel System

Check engine-oil and coolant levels before operation. Inspect belts, hoses, clamps, wiring, mounts, and leakage. Use the fuel, oil, coolant, and filters specified for the installed Yanmar engine.

Stop the engine before fuel-system service. Clean the area around fittings and prevent dirt from entering. Drain water and sediment from the separator and tank as specified. Bleed air after the system has run dry or a line or filter has been opened. Never use a hand to locate a high-pressure leak.

Air Filter

Inspect the air-cleaner restriction indicator and element more frequently in dusty conditions. Clean or replace the primary element according to the approved procedure. Never operate without the element. Do not strike it against a hard surface or use a damaged element. Replace the safety element rather than cleaning it unless the engine manufacturer's procedure specifically permits otherwise.

Clean the housing and sealing surfaces before installation. Make sure clamps, hoses, and dust valves are secure and free of cracks.

Cooling System

Check coolant only after the system has cooled. Maintain the specified coolant mixture and do not mix incompatible types. Inspect the radiator, cap, hoses, clamps, fan, belt, water pump, overflow container, and engine for leaks or damage.

Keep the radiator core clear without bending the fins. If coolant is drained, refill slowly and purge trapped air. Run the engine, allow it to cool, and recheck the level. Never use untreated water where freeze, boil, corrosion, or cavitation protection is required.

Electrical System

Turn the battery disconnect OFF before electrical repair, except when an approved powered diagnostic test requires otherwise. Protect wiring from heat, abrasion, moisture, oil, and sharp edges. Replace damaged insulation and secure loose connectors and clips.

Use the correct fuse rating. Never bypass a fuse or install a larger fuse to stop repeated opening. Find and repair the circuit fault. Disconnect the battery and protect electronic controllers before welding.

Hydraulic System

Hydraulic fluid may remain hot and pressurized after shutdown. Lower the attachment, stop the engine, operate the controls to release stored pressure, and loosen the tank cap slowly.

Use cardboard or wood to check for leaks. Fluid injected through the skin is a medical emergency and requires immediate treatment. Replace damaged hoses, tubes, seals, guards, and clamps. Cap open lines and ports immediately to prevent contamination.

Check oil level with the machine in the specified service position. Use only clean hydraulic oil of the approved grade. After component replacement, purge air using slow, low-idle movements and inspect for leakage.

Swing Drive and Reduction Gear

Check reduction-gear oil at the specified interval with the machine level. Clean around plugs before removal. Use the specified oil and tighten plugs correctly. Inspect drained oil for water, metal, or abnormal contamination. Do not operate with low oil or a leaking seal.

Greasing

Clean each fitting before applying grease. Grease boom, arm, bucket, cylinder, blade, boom-offset, and attachment pins at the intervals shown on the lubrication chart. Apply grease until clean grease appears at the joint when the procedure calls for it, then remove excess grease.

Grease work-equipment pins after water, mud, pressure-washing, or other conditions that remove lubricant. Use only the specified grease.

Track Tension

Park on firm, level ground and support the machine securely before checking track sag. The tensioner contains grease at very high pressure. Never remove the grease fitting or place any part of the body in front of the relief valve.

Add grease slowly to increase tension. To decrease tension, loosen the relief valve gradually and no more than one turn. If grease does not flow, stop and obtain qualified service. Do not disassemble a pressurized tensioner.

Adjust both tracks to the specification shown for the installed track type. Over-tight tracks accelerate bearing, roller, and track wear; loose tracks can derail.

Bucket-Clearance Adjustment

Lower and support the bucket before adjustment. Stop the engine, remove the key, engage the safety lock, and prevent all attachment movement. Use the specified shims and fastener torque. Maintain adequate side clearance without excessive looseness. Never place fingers between the arm, bucket, linkage, or shims while aligning components.

Lubrication and Inspection Schedule

Lubrication reduces friction, excludes contaminants, and extends pin and bearing life. Use the maintenance chart as the controlling schedule and shorten intervals for dust, water, mud, breaker use, high temperatures, or continuous heavy load.

At a minimum, complete daily or 10-hour checks of engine oil, coolant, fuel, hydraulic oil, leakage, air-cleaner condition, safety devices, controls, track condition, and required grease points. Complete initial 50-hour, 250-hour, 500-hour, 1,000-hour, and 2,000-hour services described in this manual and the installed engine manual.

Record the date, operating hours, work performed, fluid specifications, and replacement parts for every service.