The 289D and Its Role in Compact Track Loading
The Caterpillar 289D compact track loader was introduced as part of CAT’s D-series lineup, offering enhanced hydraulic performance, improved cab comfort, and Tier 4 Final emissions compliance. With an operating weight of around 10,000 lbs and a rated operating capacity of 3,800 lbs, the 289D is widely used in grading, demolition, landscaping, and utility work. Its electronically controlled diesel engine and high-flow hydraulic system make it a versatile tool across job types.
However, when a 289D begins to require starting fluid to fire up—especially in warm weather—it signals a deeper issue in the fuel delivery or combustion system. While the machine may run well once started, the hard start condition can lead to long-term damage if left unresolved.
Terminology Notes

• Starting Fluid: A volatile ether-based spray used to aid cold starts by igniting more easily than diesel.
  
• Fuel Rail Pressure: The pressure at which fuel is delivered to the injectors, critical for proper atomization.
  
• Glow Plug: A heating element used to warm the combustion chamber in diesel engines.
  
• Cranking RPM: The rotational speed of the engine during startup, affecting compression and fuel delivery.
  
• ECM (Engine Control Module): The onboard computer that manages fuel injection, timing, and diagnostics.
  

• The engine cranks but fails to fire without external aid
  
• Once running, it performs adequately or “great-ish”
  
• No active fault codes may be present
  
• Fuel filters may have been recently changed
  
• Glow plug system may appear functional
  

• Use a diagnostic scanner to monitor fuel rail pressure during cranking
  
• Check for minimum required pressure (typically 4,000–5,000 PSI)
  
• Inspect fuel lines for air intrusion or leaks
  
• Test lift pump output and verify priming function
  
• Check injector return flow for excessive leakage
  
• Monitor glow plug voltage and current draw
  

• CAT ET or compatible diagnostic software
  
• Fuel pressure gauge with adapter for common rail
  
• Multimeter for glow plug circuit testing
  
• Clear fuel line for visual air detection
  

• Weak Fuel Pump
  • Symptoms: Low rail pressure during cranking
    
  • Solution: Replace high-pressure pump, inspect drive gear
    
• Injector Leakage
  • Symptoms: Fuel returns too quickly, pressure drops
    
  • Solution: Replace faulty injectors, test with return flow kit
    
• Air in Fuel System
  • Symptoms: Bubbles in line, delayed start
    
  • Solution: Bleed system, replace cracked lines or fittings
    
• Glow Plug Failure
  • Symptoms: Poor cold start, white smoke
    
  • Solution: Replace glow plugs, test relay and timer
    
• ECM Fault or Sensor Error
  

• Symptoms: Incorrect timing or fuel delivery
  
• Solution: Reflash ECM, replace cam/crank sensors if out of sync
  

• Replace fuel filters every 500 hours
  
• Use winter-grade diesel or additives in cold climates
  
• Inspect fuel lines quarterly for wear and leaks
  
• Monitor battery voltage and cranking RPM
  
• Keep diagnostic logs for startup behavior
  

Buckets, an essential part of many heavy machinery tools, experience significant wear during operations. Whether you're using a loader, excavator, or any other earthmoving equipment, the wear bars are subjected to intense forces, causing damage over time. The wear bar repair process is crucial for maintaining the performance and longevity of the bucket, ensuring optimal productivity and reducing downtime.
This article explores the importance of wear bars, common issues that lead to their wear, and best practices for repairing them, all while diving into the key aspects of maintaining your equipment in excellent working condition.
Understanding the Role of Wear Bars in Buckets
Wear bars are designed to protect the bucket's most vulnerable components, typically the cutting edge and sides, from excessive abrasion and damage. They are usually made of highly durable materials like steel or tungsten carbide and are welded onto the bucket. As the machine operates, the wear bars absorb the brunt of the abrasive materials, such as dirt, gravel, and rock, keeping the main bucket structure intact.
By adding wear bars, the bucket's lifespan is significantly extended, reducing the frequency and cost of replacements. However, just like any other part of a machine, wear bars themselves will eventually wear out and require maintenance or replacement.
Common Causes of Wear Bar Damage
Several factors contribute to wear bar degradation, including:
1. Excessive Abrasive Use
Buckets frequently encounter abrasive materials, such as gravel, sand, and crushed rock. These materials create significant friction against the wear bars, leading to gradual wear. The more abrasive the material, the faster the wear bars will deteriorate.
2. Overloading
Overloading the bucket puts excessive strain on the wear bars. The added weight and force cause the wear bars to experience more pressure than they are designed for, accelerating their wear rate and leading to cracks or breakage.
3. Impact with Hard Objects
Impact damage from hard objects like large rocks, concrete debris, or other unyielding materials can cause the wear bars to chip, crack, or even break off entirely. This kind of damage can often lead to the need for immediate repair or replacement.
4. Improper Operation
Inexperienced operators or poor machine operation, such as using the bucket at the wrong angle or digging into materials too aggressively, can cause excessive stress on the wear bars. Improper operation can lead to uneven wear or sudden damage, forcing early repairs.
5. Corrosion
Environmental factors, like exposure to moisture and chemicals, can cause corrosion. If wear bars aren't maintained properly, rust can set in, weakening the metal and reducing their ability to withstand pressure.
Repairing the Wear Bars
When wear bars begin to show signs of damage, timely repair or replacement is necessary to prevent further damage to the bucket and improve operational efficiency. Here's how to repair bucket wear bars:
1. Inspection and Evaluation
Before attempting any repairs, a thorough inspection should be conducted to assess the damage. Look for the following:

• Cracks or Breaks: Any significant cracks or broken sections of the wear bar should be addressed immediately. If the wear bar is severely cracked or missing, it's best to replace it entirely.
  
• Worn Down Surfaces: If the wear bars have worn thin but are not cracked, they may still have some life left and can be welded with additional material to restore their function.
  

• Use of Tools: A cutting torch or grinder is used to carefully remove the damaged wear bar. Ensure that you remove all of the old material without damaging the bucket's main structure.
  
• Preparation for New Wear Bars: Once the old wear bars are removed, clean the area thoroughly. Remove any rust, dirt, or debris, ensuring that the new wear bar will adhere securely.
  

• High-abrasion environments (such as gravel pits) may require tungsten carbide wear bars for maximum durability.
  
• General work environments can use standard hardened steel wear bars.
  

• Preheat the Surface: Preheating the bucket’s surface helps avoid warping when welding.
  
• Even Weld: Use a consistent welding bead around the entire perimeter of the wear bar to ensure that it will stay in place.
  
• Check for Gaps: Ensure there are no gaps between the wear bar and the bucket to avoid potential wear and tear.
  

The Dual Demands of Salvage Yards and Gravel Pits
Running both a salvage yard and a gravel pit requires equipment that can handle a wide range of tasks—from lifting crushed vehicles and scrap metal to loading aggregate into trucks. A wheel loader becomes the backbone of such operations, offering mobility, lifting power, and versatility across uneven terrain and cluttered work zones. Selecting the right model means balancing breakout force, bucket capacity, maneuverability, and long-term serviceability.
In Arkansas, where terrain can range from clay-rich soil to rocky deposits, and salvage yards often deal with tight quarters and unpredictable loads, the loader must be both nimble and rugged. It’s not just about horsepower—it’s about how the machine handles daily abuse and adapts to shifting priorities.
Terminology Notes

• Breakout Force: The force required to lift or pry material from the ground, critical for gravel and compacted loads.
  
• Articulated Steering: A central pivot design that allows the loader to turn sharply, ideal for tight salvage yard layouts.
  
• ROPS/FOPS: Roll-over and falling object protection structures that shield the operator in hazardous environments.
  
• Hydrostatic Transmission: A fluid-driven system offering smooth speed control, often preferred in stop-and-go salvage work.
  
• Quick Coupler: A mechanism allowing fast attachment changes without manual pin removal.
  

• Operating weight: 12,000–20,000 lbs for stability and lift capacity
  
• Bucket size: 2.0–3.5 cubic yards for gravel, with fork or grapple options for salvage
  
• Engine power: 120–180 hp for consistent performance under load
  
• Tire type: L2 or L3 bias or radial tires for mixed terrain durability
  
• Visibility: Elevated cab with wide glass for spotting hazards and aligning loads
  

• Caterpillar: Known for parts availability and dealer support
  
• Volvo: Offers excellent operator comfort and fuel efficiency
  
• Komatsu: Durable with strong resale value
  
• Case: Affordable and easy to maintain
  
• Hyundai and Doosan: Competitive pricing with solid performance
  

• Check articulation joints for play or cracking
  
• Inspect hydraulic cylinders for leaks or scoring
  
• Test transmission response under load
  
• Review service records and hours (under 8,000 is ideal)
  
• Verify bucket pins and bushings for excessive wear
  

• Add a hydraulic grapple for lifting car bodies and scrap bundles
  
• Use pallet forks for engine blocks and transmissions
  
• Install a high-dump bucket for loading tall-sided trucks
  
• Consider a scale-integrated bucket for weighing gravel loads
  
• Add rear-view camera and LED work lights for safety
  

• Grease pivot points daily during active use
  
• Change hydraulic fluid every 1,000 hours
  
• Inspect tires weekly for cuts and wear
  
• Replace air filters monthly in dusty gravel environments
  
• Monitor transmission fluid and cooling system seasonally
  

The Komatsu PC78MR-6 is a highly regarded compact midi excavator, known for its durability, reliability, and efficiency. It is often used in tight spaces and offers exceptional maneuverability, making it a popular choice in urban construction and landscaping projects. One of the crucial components that keep the PC78MR-6 in optimal working condition is the track tensioner, a system that ensures the tracks remain tight, preventing excessive wear and providing stability to the machine.
In this article, we will explore the role of the track tensioner in the Komatsu PC78MR-6, the common issues operators might face, and provide maintenance tips to ensure the machine’s tracks function efficiently throughout its lifecycle.
Role of the Track Tensioner in Excavators
The track tensioner on the PC78MR-6 is responsible for maintaining the correct tension on the tracks of the machine. Proper track tension is critical for several reasons:

• Preventing Track Wear: Too tight a tension can cause excessive wear on the track components, including the rollers, sprockets, and links. On the other hand, loose tracks can cause skipping or slipping, which may lead to further damage and reduced efficiency.
  
• Improving Stability and Performance: Proper track tension ensures that the tracks maintain constant contact with the ground, which improves the machine's overall stability, traction, and performance. This is especially important in challenging terrain or when carrying heavy loads.
  
• Maintaining Hydraulic System Efficiency: The track tensioner is part of the machine’s undercarriage system, which includes hydraulic cylinders and pumps. Properly adjusted tracks reduce strain on the hydraulic components, ensuring efficient operation.
  

• Hydraulic Leaks: The hydraulic cylinder in the track tensioning system can develop leaks, causing a loss of pressure and, consequently, improper tensioning of the tracks.
  
• Worn or Damaged Springs: In mechanical track tensioners, the spring mechanism can wear out, losing its ability to maintain the proper tension on the tracks.
  
• Environmental Factors: Extreme operating conditions, such as high temperatures or muddy terrain, can affect the tensioning system. Dirt and debris can accumulate in the tracks, interfering with the track tensioner’s functionality.
  

• Checking Track Tension: To check track tension, lift the machine slightly off the ground and use a tension gauge to measure the amount of deflection on the tracks. Follow the guidelines in the operator’s manual to adjust accordingly.
  

John Deere’s Entry into the Telehandler Market
John Deere, a name long associated with agricultural and construction equipment, entered the telehandler market in the early 2000s through a partnership with European manufacturers. Their branded telehandlers—often built by Matbro or Kramer and rebadged for North American distribution—were designed to serve contractors, farmers, and industrial users needing reach, lift, and maneuverability in tight spaces. These machines featured telescopic booms, four-wheel drive, and load capacities ranging from 5,000 to 10,000 lbs.
Despite Deere’s strong dealer network and brand loyalty, their telehandlers never gained the same traction as their tractors, loaders, or excavators. By the mid-2000s, John Deere quietly exited the telehandler segment, leaving a gap in their product lineup and sparking questions about strategic priorities.
Terminology Notes

• Telehandler: A telescopic handler used for lifting and placing materials at height or distance.
  
• Boom Reach: The horizontal extension capability of the telescopic boom.
  
• Load Chart: A diagram showing safe lifting capacities at various boom angles and extensions.
  
• Frame-Leveling: A feature allowing the chassis to tilt for stability on uneven terrain.
  
• Auxiliary Hydraulics: Additional hydraulic circuits used to power attachments like buckets or grapples.
  

• Limited Market Share
  • Competing against established brands like JLG, Genie, Manitou, and SkyTrak proved difficult
    
  • Deere’s telehandlers were often perceived as rebranded imports rather than purpose-built machines
    
• Dealer Support Complexity
  • Parts sourcing and service training for European-built units created friction in North American dealerships
    
  • Mechanics accustomed to Deere’s core product lines struggled with unfamiliar hydraulic and electrical systems
    
• Strategic Refocus
  

• Deere chose to concentrate on core segments: tractors, skid steers, wheel loaders, and excavators
  
• Telehandlers lacked the volume and margin to justify continued investment
  

• Difficulty sourcing OEM parts, especially for boom assemblies and hydraulic valves
  
• Limited technical documentation and service bulletins
  
• Reduced resale value due to perceived orphan status
  
• Need to retrofit or cross-reference parts from original European manufacturers
  

• Identifying original build sources (e.g., Matbro, Kramer) and sourcing parts directly
  
• Joining telehandler owner forums and vintage equipment groups for support
  
• Fabricating custom components when OEM parts were unavailable
  
• Upgrading hydraulic fittings and electrical connectors to standard North American specs
  

• Dedicated engineering for lift stability and boom control
  
• Broad attachment compatibility and quick coupler systems
  
• Strong dealer support with trained technicians and stocked parts
  
• Clear load charts and safety systems for jobsite compliance
  

Aveling-Barford, a name synonymous with heavy equipment, has a rich history in manufacturing construction machinery, particularly graders. Founded in the late 19th century, the company quickly established itself as a key player in the road-building industry. The Aveling-Barford graders, once popular across the world, were highly regarded for their durability, performance, and ability to handle tough construction tasks. In this article, we will take an in-depth look at the legacy of the Aveling-Barford graders, their design features, and why they remain relevant even in today’s evolving machinery market.
Aveling-Barford: A Brief History
The history of Aveling-Barford dates back to the late 19th century, when it was established in 1865 as Aveling & Porter. The company initially focused on steam-powered engines and road rollers, but over the years, it expanded into a full range of construction machinery. In the 20th century, the company merged with Barford & Perkins, leading to the creation of Aveling-Barford as it is known today.
Aveling-Barford became renowned for its road construction machinery, particularly its graders and rollers. The company’s graders were designed to efficiently shape the landscape, ensuring smooth, level surfaces for roads, highways, and runways. Aveling-Barford graders were built to last, with many models still in use today, despite their age.
In the 1980s and 1990s, however, the company faced financial struggles and was eventually acquired by Volvo in 1991. Despite this acquisition, Aveling-Barford's legacy continues to be felt in the construction machinery industry, and vintage Aveling-Barford graders remain popular among collectors, contractors, and vintage machinery enthusiasts.
Design Features of Aveling-Barford Graders
Aveling-Barford graders were designed for heavy-duty use and built to withstand the rigors of road construction. The key features that made these machines stand out included:

• Solid Steel Construction: Aveling-Barford graders were known for their robust and durable steel frames. This heavy-duty construction ensured that the machine could handle tough work environments and carry large loads.
  
• Engine Performance: The graders were typically equipped with reliable diesel engines that provided substantial power for grading and moving earth. These engines were designed to be long-lasting and efficient, often lasting for many years with proper maintenance.
  
• High Ground Clearance: A high ground clearance was a key feature in the design of Aveling-Barford graders, enabling them to work effectively on uneven terrain without causing damage to the machine.
  
• Manual Control Systems: Many older models of Aveling-Barford graders were equipped with manual controls for adjustments, giving operators more direct control over grading tasks. This feature was valued by operators who preferred a hands-on approach to fine-tuning the machine’s performance.
  
• Versatility in Blade Adjustments: The grading blade on these machines could be adjusted to perform a variety of tasks, from leveling surfaces to creating precise slopes for drainage. These adjustments were typically controlled through a combination of manual and hydraulic systems.
  
• Large Tires and Balanced Design: The graders were equipped with large, durable tires that provided excellent traction and stability, especially on rough and uneven surfaces. This balanced design ensured that the grader could operate efficiently under a variety of load conditions.
  

• Engine Wear and Tear: Over time, the engines of older Aveling-Barford graders can experience wear and tear, leading to issues such as reduced power, difficulty starting, or overheating. Regular maintenance, including oil changes, cooling system checks, and air filter replacement, can help extend the engine’s life.
  
• Hydraulic System Failures: The hydraulic systems on older graders can sometimes develop leaks or lose pressure, affecting the blade's responsiveness and performance. Regular inspection of hydraulic lines, seals, and pumps is essential to identify and address potential issues before they become major problems.
  
• Worn Out Blades and Teeth: The grading blades and teeth can become worn out over time, especially when used in tough conditions. Regular inspections and replacing blades or teeth when they show signs of excessive wear are crucial for maintaining the grader's efficiency.
  
• Electrical Issues: As with many older machines, electrical components such as wiring, switches, and relays may deteriorate over time. Inspecting the electrical system regularly and replacing any faulty components can prevent more serious electrical issues from developing.
  
• Tire Wear: The large tires on Aveling-Barford graders can wear down over time, especially if the machine is used on rough terrain. Replacing tires when they show signs of excessive wear will help maintain the machine's stability and traction.
  

The Birth of the TD-6 and International Harvester’s Engineering Vision
The International TD-6 crawler tractor was introduced in the late 1930s by International Harvester, a company that had already made its mark in agricultural machinery and industrial equipment. By 1941, the TD-6 had become a staple in small-scale earthmoving, logging, and wartime infrastructure projects. With a rated drawbar horsepower of around 25 and an operating weight of roughly 8,000 lbs, the TD-6 was compact but capable, designed to serve contractors, farmers, and military engineers alike.
What set the TD-6 apart was its dual-engine starting system—a gasoline pony motor used to start the main diesel engine. This approach was common in pre-war diesel equipment, where electric starters lacked the torque and reliability needed to crank cold diesel engines. The TD-6’s design reflected a transitional era in heavy machinery, where mechanical ingenuity bridged the gap between simplicity and power.
Terminology Notes

• Pony Motor: A small gasoline engine used to start a larger diesel engine by spinning it up to cranking speed.
  
• Diesel Conversion: The process of switching from gasoline start to direct electric start or full diesel ignition.
  
• Magneto Ignition: A self-contained ignition system used in early gasoline engines, generating spark without a battery.
  
• Dry Clutch: A friction clutch not immersed in oil, used to engage the transmission.
  
• Crawler Tractor: A tracked machine designed for pushing, pulling, and grading tasks.
  

• Open the decompression valves on the diesel engine
  
• Start the pony motor using a hand crank or electric starter
  
• Allow the pony motor to warm up and engage the diesel flywheel
  
• Once spinning, close the decompression valves and switch fuel delivery to diesel
  
• Monitor exhaust and engine tone for successful ignition
  

• Pony motor magneto failure due to moisture or age
  
• Carburetor clogging from varnished fuel
  
• Diesel injector leakage or poor atomization
  
• Decompression valve sticking or misalignment
  
• Clutch plate glazing from long-term inactivity
  

• Rebuild magneto with new coil and condenser
  
• Ultrasonic clean carburetor and replace float needle
  
• Bench-test injectors and replace with matched spray pattern units
  
• Lap decompression valves and verify seating
  
• Resurface clutch plates and adjust linkage tension
  

• Flush hydraulic fluid and replace with ISO 32 or equivalent
  
• Inspect hoses for dry rot and replace with modern braided lines
  
• Rebuild lift cylinder with new seals and wipers
  
• Clean control valve and verify spool movement
  
• Add inline filter to prevent contamination
  

• Check track tension and adjust using recoil spring bolts
  
• Inspect rollers for flat spots or seized bearings
  
• Measure sprocket tooth wear and replace if hooked
  
• Clean clutch compartments and verify engagement
  
• Use SAE 90 gear oil in transmission and final drives
  

• Store indoors or under tarp to prevent rust
  
• Drain fuel and oil during long-term storage
  
• Keep battery disconnected to preserve wiring
  
• Document serial numbers and casting codes for historical records
  
• Join vintage tractor clubs for parts sourcing and community support
  

The TCM FB20H2 is a 48-volt electric forklift that is widely used in various industrial and warehouse settings. Known for its reliability and efficient performance, this forklift is designed to handle heavy loads with ease while providing low operating costs and minimal environmental impact. In this article, we will dive into the features, common issues, maintenance tips, and troubleshooting procedures for the TCM FB20H2, along with the key specifications that make it a preferred choice for many businesses.
TCM: A Brief History and Background
TCM Corporation, established in 1949 in Japan, is a leading manufacturer of forklifts and other material handling equipment. The company has a long-standing reputation for producing durable, high-performance equipment that caters to a wide range of industries, including warehousing, logistics, and construction. TCM forklifts are known for their innovative technology, reliability, and user-friendly features, making them a popular choice worldwide.
The TCM FB20H2 electric forklift is part of TCM’s commitment to providing environmentally friendly and efficient solutions. As an electric-powered forklift, the FB20H2 offers the advantages of reduced emissions, lower operating costs, and quieter operation compared to its internal combustion counterparts.
Key Features of the TCM FB20H2
The TCM FB20H2 48V forklift is designed to handle a variety of lifting and material handling tasks in confined spaces, making it ideal for warehouse applications. Some of its standout features include:

• 48-Volt Electric Power: The forklift is powered by a 48V battery, which provides adequate power for standard lifting tasks while reducing maintenance needs. This battery-powered system is quieter, more eco-friendly, and more energy-efficient than internal combustion engines.
  
• Load Capacity: The TCM FB20H2 is capable of lifting loads up to 2,000 kg (4,400 lbs), making it suitable for light to medium-duty lifting tasks in warehouse and distribution center environments.
  
• Compact Design: The forklift’s compact size and tight turning radius allow it to navigate narrow aisles and confined spaces with ease, maximizing operational efficiency in areas with limited space.
  
• Regenerative Braking: One of the key benefits of the TCM FB20H2 is its regenerative braking system, which helps to extend the life of the battery and improve energy efficiency by converting braking energy back into electrical power.
  
• Ergonomic Controls: The forklift features user-friendly controls and an ergonomic operator seat that ensures comfort during long shifts. Adjustable steering and pedals allow operators of various sizes to work comfortably.
  

• Faulty Charger: Check the charger for any visible damage or malfunction. Sometimes, the issue may lie with the charger itself. Ensure that the charger is providing the correct voltage and current.
  
• Battery Issues: Over time, batteries can degrade and lose their ability to hold a charge. Check the battery terminals for corrosion and ensure the battery is securely connected.
  
• Loose Connections: Inspect the wiring and connections to ensure that there are no loose or disconnected wires that could be preventing proper charging.
  

• Hydraulic Fluid Levels: Check the hydraulic fluid levels to ensure they are within the recommended range. Low fluid levels can cause the lift function to be sluggish or unresponsive.
  
• Hydraulic Leaks: Inspect the hydraulic lines and cylinders for any signs of leaks. A leak can reduce the efficiency of the lift system and cause performance issues.
  
• Motor Overheating: The motor may be overheating due to overuse or insufficient cooling. Ensure that the motor is clean and not obstructed by dust or debris.
  

• Low Steering Fluid: Check the fluid levels in the steering system. Low fluid can lead to stiff or unresponsive steering.
  
• Damaged Steering Components: Inspect the steering linkage for any damage or wear. Worn components, such as the steering shaft or power steering pump, can affect the forklift’s maneuverability.
  
• Electrical Faults: If the steering is powered by an electric system, check for electrical faults or issues with the power steering motor or connections.
  

• Loose or Corroded Connections: Loose or corroded electrical connections can cause intermittent faults, which may trigger error codes. Ensure all electrical components are securely connected.
  
• Faulty Sensors: If the forklift is displaying error codes related to sensors, check for damaged or malfunctioning sensors that may need to be replaced.
  

• Battery Maintenance: Regularly check the battery’s water level and ensure the terminals are clean and corrosion-free. Battery terminals should be tightly connected, and the battery should be fully charged when not in use.
  
• Hydraulic System Inspection: Inspect the hydraulic system for leaks, and check fluid levels regularly. Replace the hydraulic fluid as recommended by the manufacturer.
  
• Tire and Wheel Maintenance: Check the tires for wear and replace them when necessary. Make sure the wheels are properly aligned to ensure smooth operation.
  
• Brake System: Inspect the braking system regularly, including the regenerative braking system. Ensure that the brakes are functioning properly and are free from wear.
  
• Routine Cleaning: Keep the forklift clean and free of debris. Dust and dirt can affect the performance of the forklift, especially in the motor and electrical systems.
  

Clark’s Industrial Legacy and the 4-Ton Workhorse
Clark Material Handling Company, founded in 1917, is credited with inventing the first industrial truck. Over the decades, Clark forklifts became synonymous with durability and simplicity, especially in warehouse and yard operations. The 4-ton model, widely used in the 1970s and 1980s, was built for mid-range lifting tasks—steel, lumber, machinery—without the complexity of modern electronics. Its mechanical systems, including a gear-driven transmission and open-center hydraulics, made it a favorite among operators who valued serviceability over sophistication.
Many of these machines still exist today, often parked for years before being revived by determined owners. One such case involved a Clark 4-ton unit that had sat idle for three years. After coaxing the engine back to life, the operator faced a new challenge: a hydraulic mast system that refused to lift anything beyond its own weight and dropped rapidly when raised.
Terminology Notes

• Hydraulic Mast System: The vertical lifting assembly powered by hydraulic cylinders.
  
• Main Cylinder: The primary actuator responsible for raising the forks and carriage.
  
• Control Valve: A directional valve that regulates fluid flow to the cylinders.
  
• Relief Valve: A pressure-limiting valve that protects the system from overload.
  
• One-Way Cylinder: A hydraulic cylinder that extends under pressure and retracts by gravity or load.
  

• Inspect hydraulic fluid level and condition (should be clean, amber, and free of foam)
  
• Check for air in the system by cycling the mast and observing for jerky movement
  
• Remove and inspect the control valve for debris, scoring, or stuck spools
  
• Test relief valve pressure setting (typically ~2,000 PSI for mid-size forklifts)
  
• Examine cylinder seals for internal bypass using a deadhead test
  

• Pressure gauge with quick-connect fittings
  
• Valve body schematic or service manual
  
• Clean workbench for valve disassembly
  
• Seal kit matched to cylinder bore and rod diameter
  

• Remove cylinder from mast and drain fluid
  
• Disassemble gland nut and extract piston
  
• Inspect seals for nicks, hardening, or deformation
  
• Measure rod straightness and piston clearance
  
• Replace with OEM or aftermarket seal kit
  

• Stuck spools due to varnish or corrosion
  
• Weak relief spring causing premature pressure bleed
  
• Worn seats or O-rings allowing internal leakage
  
• Contaminated fluid clogging pilot passages
  

• Disassemble valve and clean all components with solvent
  
• Replace O-rings and seals using Viton for heat resistance
  
• Polish spool surfaces with emery cloth
  
• Reassemble with torque specs and test under load
  
• Adjust relief valve using shims or screw setting
  

• Change fluid every 500 hours or annually
  
• Replace filter and clean suction screen
  
• Use ISO 46 hydraulic oil with anti-wear additives
  
• Inspect hoses quarterly for abrasion and leaks
  
• Keep reservoir sealed to prevent moisture ingress
  

John Deere and Komatsu are two of the most prominent manufacturers of heavy equipment worldwide. While both brands are well-established and respected, they have distinct characteristics and strengths that appeal to different types of industries and applications. Understanding these differences can help businesses and operators choose the right equipment for their needs. This article explores the key distinctions between John Deere and Komatsu, focusing on their equipment offerings, performance, durability, customer support, and global reach.
Brand History and Reputation
John Deere:
John Deere, founded in 1837 by John Deere himself, is one of the oldest and most recognizable brands in the agricultural and construction equipment sectors. Initially, John Deere made its name with plows and farming tools, but by the 20th century, the company expanded into producing construction equipment. Today, John Deere is a global leader in manufacturing construction, forestry, and agricultural machinery.
The brand is synonymous with reliability and innovation, with a focus on producing user-friendly, durable machines designed for heavy-duty tasks. John Deere’s iconic green and yellow color scheme has become a symbol of the brand, and its equipment is widely used across the world.
Komatsu:
Komatsu, established in 1921, is a Japanese multinational corporation specializing in the production of construction, mining, and military equipment. Over the years, Komatsu has earned a reputation for high-tech innovations and cutting-edge designs in heavy machinery. While it initially focused on developing mining equipment, Komatsu has expanded into numerous other sectors, including construction and forestry.
Known for its high-performance, durable machines, Komatsu emphasizes advanced technology, such as automation, fuel efficiency, and enhanced safety features. The brand is often regarded for its attention to detail in engineering and innovation, offering some of the most technologically advanced machines in the market.
Product Offerings and Innovation
John Deere’s Equipment Range:
John Deere’s range of construction equipment spans across excavators, dozers, backhoe loaders, skid steers, and motor graders. The brand is known for producing versatile, robust machines with a strong focus on operator comfort and ease of use. Key product lines include:

• Excavators: John Deere’s excavators are known for their durability, fuel efficiency, and easy maintenance. The 350G LC, for instance, is designed for heavy digging applications, offering a balance between power and fuel economy.
  
• Dozers: John Deere’s crawler dozers, like the 850K, are known for their high pushing power and excellent stability on rough terrains. They are equipped with advanced hydrostatic transmissions and provide smoother, more efficient performance.
  
• Skid Steers: John Deere’s skid steer loaders are widely praised for their versatility, ease of operation, and quick attachment change systems.
  
• Motor Graders: John Deere also produces motor graders such as the 670G, designed for fine grading applications in construction and road building.
  

• Excavators: Komatsu’s hydraulic excavators, such as the PC360LC-11, are renowned for their fuel efficiency, strong lifting capacities, and long-lasting performance. The company emphasizes innovation with features like KOMTRAX, their machine monitoring system, which provides real-time performance data.
  
• Dozers: Komatsu’s D61EX-24 and D65EX-18 dozers are designed to provide maximum power and efficiency for heavy grading and earth-moving tasks. The company’s dozers are equipped with powerful engines and advanced hydraulic systems that make them ideal for tough conditions.
  
• Wheel Loaders: Komatsu’s wheel loaders, such as the WA470-8, are known for their powerful lifting capabilities and exceptional stability. Their hydraulics are designed to improve productivity while maintaining fuel efficiency.
  
• Dump Trucks and Haulers: Komatsu is a leading name in mining and haulage, offering massive haul trucks like the HD785-7, known for their incredible payload capacities and fuel-efficient engines.