The Role of Sandblasting in Equipment Maintenance
Sandblasting is a surface preparation technique that uses compressed air to propel abrasive media against metal, concrete, or other substrates. In the context of heavy equipment, it is primarily used to remove rust, old paint, scale, and contaminants before repainting or repair. The process creates a clean, profiled surface that promotes adhesion of coatings and extends the life of machinery exposed to harsh environments.
Terminology Note: “Media” refers to the abrasive material used in blasting, such as silica sand, aluminum oxide, crushed glass, or steel grit. “CFM” (cubic feet per minute) measures the volume of air a compressor delivers, which directly affects blasting speed and efficiency.
In 2023, a restoration crew in Alberta used sandblasting to strip a 1970s grader down to bare metal. The job revealed hidden cracks in the moldboard and frame, allowing repairs before repainting. Without blasting, those flaws would have remained buried under layers of paint and corrosion.
Choosing the Right Compressor and Blast Pot
The effectiveness of sandblasting depends heavily on the air compressor and blast pot setup. For small jobs like truck frames, rims, or trailer touch-ups, a compressor delivering 24 CFM at 90 PSI may suffice—but productivity will be limited. Larger jobs require more air volume and media capacity.
Recommended configurations:

• Small-scale setup:
  • Compressor: 24–30 CFM at 90 PSI
    
  • Blast pot: 100–150 lb pressure pot
    
  • Media: Fine crushed glass or aluminum oxide
    
  • Use case: Touch-ups, small parts, spot blasting
    
• Mid-scale setup:
  • Compressor: 185 CFM tow-behind unit
    
  • Blast pot: 300–600 lb pressure pot
    
  • Media: Silica sand or steel grit
    
  • Use case: Truck frames, loader arms, buckets
    
• Large-scale setup:
  

• Compressor: 375–600 CFM
  
• Blast pot: 600+ lb with dual hose capability
  
• Media: Garnet or coal slag
  
• Use case: Full machine restoration, structural steel
  

• Pressure feed:
  • Media is pressurized in a sealed pot and forced through the hose
    
  • Offers consistent flow and higher productivity
    
  • Ideal for professional and industrial use
    
• Gravity feed:
  

• Media flows from a hopper above the nozzle using gravity
  
• Inexpensive but prone to clogging and inconsistent flow
  
• Suitable only for hobby use or very light tasks
  

• Avoid gravity feed units for equipment restoration
  
• Invest in a pressure pot with adjustable media valve
  
• Use moisture separators and air dryers to prevent clogging
  
• Choose brands like Clemco, Empire, or Sandstorm for reliability
  

• Use an air dryer or desiccant system on the compressor
  
• Store media in sealed containers away from humidity
  
• Avoid reusing media unless properly screened and dried
  
• Install a moisture trap near the blast nozzle
  

• Silica sand: Cheap but hazardous due to silica dust
  
• Crushed glass: Good for paint removal, low profile
  
• Aluminum oxide: Aggressive, reusable, ideal for rust
  
• Steel grit: Heavy-duty, fast cutting, reusable
  
• Garnet: Low dust, environmentally friendly, high efficiency
  

• Wet blasting: Combines water and media, reduces airborne particles
  
• Soda blasting: Uses sodium bicarbonate, gentle on soft metals
  
• Pressure washer attachments: Inject media into water stream, low cost
  

• Wet blasting requires corrosion inhibitors post-treatment
  
• Soda blasting may not profile steel adequately for paint
  
• Pressure washer setups lack the impact force for heavy rust
  

• Full-face respirator with air supply
  
• Leather gloves and blast suit
  
• Hearing protection
  
• Controlled work area with barriers or containment
  
• Compliance with local environmental regulations
  

• Use low-dust media like garnet or glass
  
• Collect spent media for disposal or reuse
  
• Avoid blasting near food production or residential areas
  
• Monitor air quality and report excessive emissions
  

The Volvo EC460BLC is a versatile and powerful machine used primarily in heavy-duty construction and excavation projects. However, like any piece of high-performance equipment, it’s not immune to mechanical issues. One of the most common issues faced by operators and fleet managers is engine trouble, which can vary from minor inconveniences to more severe mechanical failures. When a problem arises, understanding the symptoms and knowing how to approach repairs is key to minimizing downtime and maintaining the machine’s productivity.
The Volvo EC460BLC Engine Overview
The EC460BLC is part of Volvo's well-known EC series of excavators, designed to meet the demands of tough construction sites. It features a robust diesel engine, typically a Volvo D12C or similar engine model, with a displacement of 12 liters. The engine is designed to provide a balance of fuel efficiency and power, delivering up to 200 horsepower, making it suitable for a wide range of applications including heavy lifting, digging, and demolition.
The durability of the EC460BLC's engine is one of the key selling points of the excavator. It’s engineered to withstand high pressures and long operating hours, but as with any machine, its lifespan depends on proper maintenance, timely repairs, and appropriate use.
Common Engine Issues in the EC460BLC
As with any sophisticated machinery, the engine of the Volvo EC460BLC can experience a range of problems. Some of the most common engine-related issues include:

• Loss of Power: This can be caused by various factors including a clogged fuel filter, failing turbocharger, or an issue with the fuel injectors. A loss of power may also be due to low compression in the engine cylinders.
  
• Overheating: Engine overheating is a frequent issue that can lead to serious damage if left unaddressed. Common causes include radiator issues, coolant leaks, or problems with the engine's cooling system.
  
• Excessive Smoke: Blue, black, or white smoke from the exhaust is often an indicator of engine trouble. Blue smoke generally indicates oil burning, black smoke points to excessive fuel consumption, and white smoke could suggest a coolant leak or incomplete combustion.
  
• Poor Fuel Economy: This could be a sign of fuel system malfunctions such as a failing fuel pump or clogged fuel injectors. A decrease in fuel efficiency can also be due to the engine running inefficiently or needing a tune-up.
  
• Strange Noises: Unusual engine sounds like knocking or squealing can indicate issues with the engine's internal components, such as worn bearings or valve problems.
  

• Follow the Manufacturer’s Maintenance Schedule: Volvo provides detailed maintenance schedules for the EC460BLC, including recommendations for oil changes, filter replacements, and component inspections.
  
• Use Quality Fuel and Lubricants: Always use high-quality fuel and lubricants that meet Volvo’s specifications. This helps keep the engine clean and running smoothly.
  
• Regularly Inspect the Cooling System: Overheating is a common cause of engine damage, so it’s important to check the coolant levels and ensure that the radiator is free of obstructions.
  
• Monitor Engine Performance: Pay close attention to any changes in engine performance, such as reduced power, excessive smoke, or strange noises. Catching problems early can prevent further damage.
  

The Ford 550 and Its Place in Construction Equipment History
The Ford 550 backhoe loader was introduced in the late 1970s as part of Ford’s expansion into the compact construction equipment market. Built for versatility and durability, the 550 combined a front loader with a rear-mounted backhoe, making it ideal for trenching, grading, and utility work. Powered by a 3-cylinder diesel engine producing around 55 horsepower, the machine featured mechanical simplicity and rugged hydraulics that appealed to municipalities, contractors, and farmers alike.
Ford’s industrial equipment division, which later became part of New Holland through a series of mergers, produced thousands of 550 units during its production run. The loader’s popularity stemmed from its straightforward design, ease of service, and availability of parts through Ford tractor dealerships. Even decades later, many 550s remain in active use, especially in rural fleets and restoration projects.
Common Wear Items and Replacement Needs
As with any aging machine, the Ford 550 requires regular attention to components that wear over time. Common parts that need replacement include:

• Hydraulic hoses and fittings
  
• Loader and backhoe bucket teeth
  
• Pins and bushings in pivot joints
  
• Brake shoes and master cylinder seals
  
• Steering linkages and tie rods
  
• Engine gaskets and fuel filters
  
• Transmission seals and clutch components
  

• Cross-referencing part numbers with Ford tractor catalogs
  
• Using aftermarket suppliers specializing in vintage construction equipment
  
• Salvaging components from donor machines or scrapyards
  
• Fabricating bushings, pins, and brackets using original dimensions
  
• Consulting agricultural dealers who still stock Ford industrial parts
  

• Tractor salvage yards with industrial divisions
  
• Online marketplaces with verified sellers
  
• Hydraulic shops that rebuild cylinders and valves
  
• Machine shops for custom fabrication
  
• Enthusiast forums and restoration groups
  

• Replace all hydraulic hoses with modern two-wire rated lines
  
• Install LED work lights for better visibility
  
• Upgrade seat and controls for operator comfort
  
• Add quick coupler to loader bucket for faster attachment changes
  
• Use synthetic hydraulic fluid for better cold-weather performance
  

• Daily: Check fluid levels, inspect hoses, grease pivot points
  
• Weekly: Inspect tires, clean air filter, test brakes
  
• Monthly: Torque loader frame bolts, check battery terminals
  
• Annually: Replace hydraulic filters, flush coolant, inspect clutch
  

• Hydraulic leak at control valve: Replace O-rings and clean spool bore
  
• Weak lift: Check pump output and inspect suction line for air leaks
  
• Brake fade: Rebuild master cylinder and bleed system thoroughly
  
• Engine hard start: Replace glow plugs and inspect fuel delivery
  
• Transmission slip: Adjust clutch linkage and inspect pressure plate
  

• Keep spare hoses and fittings in the cab
  
• Use portable grease gun and torque wrench
  
• Label hydraulic lines during disassembly
  
• Carry seal kits and gasket material for emergency repairs
  
• Document all repairs and parts used for future reference
  

Welding a hydraulic thumb mount to an arm stick of a construction machine is a task that requires precision, skill, and an understanding of both welding techniques and the mechanical stresses the joint will experience during operation. The thumb mount is an essential component for machines like excavators and backhoes, as it enables the machine to grip and handle objects, enhancing its versatility. The quality of the weld between the thumb mount and the arm stick will directly affect the durability and performance of the attachment. In this article, we will go through important tips and techniques for successfully welding a hydraulic thumb mount to an arm stick.
Importance of Proper Welding on Hydraulic Thumb Mounts
The hydraulic thumb is a tool attachment that allows a machine to grab, hold, and move objects, making it a valuable addition to excavators, backhoes, and similar heavy equipment. These attachments are typically welded to the arm stick, or the boom, of the machine. Given that these components are subjected to high mechanical forces during operation, it is crucial to ensure that the weld is strong and secure.
The weld itself needs to handle the combined stresses of lifting, gripping, and manipulation of heavy materials. Poorly executed welds can lead to catastrophic failures, risking both the safety of operators and the structural integrity of the machine. Proper welding techniques are therefore essential to ensure that the hydraulic thumb operates reliably and safely.
Preparing for the Weld
Before beginning the welding process, proper preparation of both the hydraulic thumb mount and the arm stick is crucial for ensuring a high-quality and strong weld. Here are the essential steps for preparation:
1. Clean the Surfaces
Welding requires clean surfaces to ensure that the metal bonds properly. Both the hydraulic thumb mount and the arm stick should be thoroughly cleaned before welding. Remove any dirt, rust, oil, or other contaminants using a wire brush, grinder, or chemical cleaning agent. Dirt or grease on the surfaces can cause porosity, leading to weak spots in the weld.
2. Inspect the Components
Examine the thumb mount and the arm stick for any signs of damage or wear. Cracks, rust, or deformities can affect the welding process and lead to potential issues later. If any of the components are damaged, repair them before proceeding with the weld.
3. Ensure Proper Alignment
Correct alignment of the thumb mount to the arm stick is essential for proper function. The thumb mount must be positioned precisely to ensure it operates smoothly and handles forces as intended. Use clamps, jigs, or other alignment tools to secure the mount in place before beginning the welding process.
4. Choose the Right Welding Materials
Select the appropriate filler material and welding rod based on the materials being welded. For steel arm sticks and thumb mounts, mild steel or alloy steel rods are typically used. However, if the components are made from high-strength steel or have special requirements, consider using filler rods that match the material's strength and composition.
Welding Process and Techniques
Now that the components are prepped, it’s time to begin the welding process. Below are some key welding tips and techniques to ensure a strong, durable joint.
1. Use the Right Welding Method
For welding a hydraulic thumb mount to an arm stick, the most common methods are Shielded Metal Arc Welding (SMAW), Gas Metal Arc Welding (GMAW), and Flux-Cored Arc Welding (FCAW). The method chosen will depend on the machine's specifications, the skill level of the welder, and the equipment available. Here's a breakdown of each method:

• SMAW (Stick Welding): This method is ideal for welding thicker materials, making it suitable for welding a thumb mount to an arm stick. Stick welding provides deep penetration, ensuring a strong bond.
  
• GMAW (MIG Welding): MIG welding is a more automated process, suitable for precise welds with less post-welding cleanup. This method is faster but may not provide the same penetration as stick welding.
  
• FCAW (Flux-Cored Welding): This method is particularly good for outdoor use because it is less sensitive to wind. FCAW is also known for providing excellent penetration and is commonly used for heavy-duty applications like this one.
  

• Weave Pattern: For a smooth, even weld, use a weave pattern to fill the gap between the thumb mount and the arm stick. This technique helps ensure even penetration and fusion between the two components.
  
• Multiple Passes: When welding thicker materials, it’s often necessary to perform multiple passes. Start with a root pass, followed by several fill passes to build up the weld. Each pass should be allowed to cool before the next one is applied to prevent overheating.
  
• Tack Welds: Begin by applying tack welds to hold the thumb mount in place. These temporary welds will secure the components during the full weld and help prevent shifting or misalignment during the process.
  

The 450K and John Deere’s Crawler Dozer Legacy
The John Deere 450K crawler dozer is part of the K-Series lineup, which includes the 550K and 650K models. Introduced to replace the J-Series, the 450K was engineered for improved fuel efficiency, operator comfort, and electronic control integration. With an operating weight of approximately 17,510 pounds and a net power rating of 80 horsepower, the 450K is designed for grading, site prep, and light-to-medium dozing tasks.
John Deere, founded in 1837, has long been a leader in agricultural and construction equipment. The K-Series dozers reflect decades of refinement, incorporating hydrostatic transmission, Eco mode, and Total Machine Control (TMC) to meet modern jobsite demands. The 450K is especially popular among contractors who need a nimble yet powerful machine for residential and commercial earthmoving.
Core Specifications and Mechanical Highlights
Key performance parameters of the 450K include:

• Engine: John Deere PowerTech PWS 4.5L FT4 diesel
  
• Net power: 80 hp (60 kW)
  
• Transmission: Dual-path hydrostatic drive
  
• Blade options: 6-way PAT (Power-Angle-Tilt) or straight blade
  
• Travel speed: Up to 6.8 mph (11 km/h)
  
• Drawbar pull: ~21,000 pounds
  
• Undercarriage: Sealed and lubricated track chain (SALT) or extended life track (XLT)
  

• Sealed-switch module (SSM) for keyless start and function control
  
• Adjustable decelerator response and steering modulation
  
• Touchpad security system with passcode protection
  
• Quiet cab environment (~75 dBA)
  
• HVAC system with defrost and fresh air intake
  

• Low fatigue during long grading sessions
  
• Responsive joystick steering and blade control
  
• Easy transition between forward and reverse
  
• Clear visibility to blade edges and surroundings
  

• Up to 20% fuel savings in light-to-medium duty cycles
  
• Reduced engine wear and lower operating temperatures
  
• Quieter operation during fine grading
  
• Extended service intervals due to lower thermal stress
  

• Use Eco mode during finish grading or light dozing
  
• Disable Eco mode when pushing heavy material or climbing grades
  
• Monitor fuel burn with onboard diagnostics
  
• Combine with auto shutdown feature to reduce idle time
  

• Plug-and-play wiring harnesses
  
• Blade-mounted sensors and receivers
  
• Calibration interface via onboard display
  
• Compatibility with 2D and 3D systems
  

• Factory-installed Topcon 3D-MC2 system
  
• Dual GPS antenna for slope and elevation control
  
• Laser receiver for pad leveling
  
• Data logging for site documentation
  

• Ground-level access to filters and fluid ports
  
• Tilt-up hood and side panels for engine access
  
• Extended service intervals with synthetic fluids
  
• Onboard diagnostics for fault codes and usage tracking
  

• Engine oil: every 500 hours
  
• Hydraulic fluid: every 1,000 hours
  
• Track tension: check weekly
  
• Blade pins and bushings: grease daily
  
• Air filter: inspect monthly
  

• Install auto-lube system for high-cycle operations
  
• Use magnetic drain plugs to monitor wear
  
• Add hydraulic fluid sampling port for lab analysis
  
• Retrofit telematics for remote diagnostics and usage tracking
  

In the world of heavy equipment, maintaining the hydraulic system is essential to ensure smooth operation and prevent costly repairs. One critical component of the hydraulic system is the hydraulic tank strainer, which plays a vital role in keeping the hydraulic fluid clean and free from contaminants. The strainer filters out debris and particles from the hydraulic fluid before it circulates through the system. Over time, dirt, metal shavings, and other contaminants can accumulate in the strainer, causing it to become clogged or inefficient. In this article, we’ll explore the importance of hydraulic tank strainers, common issues related to them, and how to maintain them effectively.
Importance of Hydraulic Tank Strainers
Hydraulic systems are the backbone of many heavy machines, powering everything from lifting arms to attachments and even steering. The hydraulic fluid that circulates throughout the system must remain clean to avoid damaging sensitive components like pumps, valves, and motors. The hydraulic tank strainer, which is typically installed inside the hydraulic reservoir, helps to filter out any foreign particles that may have entered the system.
A clean hydraulic tank strainer ensures that the hydraulic fluid is free of contaminants, allowing the system to work efficiently. However, if the strainer becomes clogged, the fluid may not flow as smoothly, resulting in poor performance and potential damage to other components of the hydraulic system.
Signs of a Clogged or Faulty Strainer
If the hydraulic tank strainer is not functioning properly, it can lead to a variety of issues that can affect the performance of the heavy equipment. Some common signs of a clogged or faulty strainer include:
1. Decreased Hydraulic Power: If the hydraulic fluid is not flowing efficiently, the machine may exhibit slower or weaker performance. This can manifest as slow lifting or tilting of the bucket, or the inability to operate attachments effectively.
2. Overheating: When the hydraulic fluid is not circulating properly due to a clogged strainer, the pump can overheat. This is because the pump is working harder to move the fluid through a restricted system, which can lead to increased wear and tear on the pump.
3. Unusual Noises: A struggling hydraulic system can produce unusual noises, such as whining or grinding sounds, which often indicate that the fluid is not circulating as it should.
4. Increased Pressure: A clogged strainer can cause excessive pressure within the hydraulic system. The system will need to work harder to achieve the desired lifting force or movement, which can strain the pump and cause it to fail prematurely.
5. Fluid Contamination: If the strainer is no longer effective at filtering debris, contaminants may start to circulate through the system, potentially causing damage to other components like valves, cylinders, and hoses.
How to Maintain and Clean a Hydraulic Tank Strainer
Proper maintenance of the hydraulic tank strainer is essential to prolong the lifespan of the hydraulic system and ensure optimal performance. Regular checks and cleaning can prevent clogs and ensure that the system is running smoothly. Here are the steps to maintain and clean the hydraulic tank strainer:
1. Regular Inspections
Inspect the hydraulic fluid regularly to ensure it is clean and free from debris. This can be done by checking the fluid’s color and consistency. Hydraulic fluid should be clear and free from contaminants. If the fluid appears cloudy or has particles floating in it, it may be time to clean the strainer.
2. Cleaning the Strainer
To clean the hydraulic tank strainer, follow these steps:

• Drain the Hydraulic Fluid: Before accessing the strainer, it is necessary to drain the hydraulic fluid from the reservoir. This can be done by opening the drain valve or using a suction pump to remove the fluid. Always dispose of the fluid according to local regulations.
  
• Locate the Strainer: The hydraulic tank strainer is typically located inside the hydraulic reservoir. It may be attached to the tank’s internal baffle or placed directly in the fluid line.
  
• Remove the Strainer: Carefully remove the strainer from the tank. Depending on the design, it may be secured with bolts or clips. Take note of its placement for reinstallation.
  
• Clean the Strainer: Once the strainer is removed, clean it thoroughly with a soft brush and solvent to remove any dirt, debris, or buildup. Avoid using harsh chemicals that could damage the strainer or other components.
  
• Check for Damage: Inspect the strainer for any signs of damage, such as holes, cracks, or excessive wear. If the strainer is damaged, it should be replaced with a new one.
  

• Use High-Quality Fluid: Always use high-quality hydraulic fluid that is appropriate for the machine’s operating conditions. Low-quality fluid can contain impurities that clog the strainer more quickly.
  
• Change Fluid Regularly: Change the hydraulic fluid at regular intervals, as recommended by the manufacturer. Old, contaminated fluid can cause strain on the system and reduce the effectiveness of the strainer.
  
• Monitor Operating Conditions: Keep an eye on the machine’s operating conditions. Excessive heat, pressure, or heavy-duty use can cause the hydraulic fluid to break down faster, leading to increased wear on the strainer.
  
• Install a Secondary Filtration System: Some operators choose to install a secondary filtration system that helps remove smaller particles from the hydraulic fluid, extending the life of the tank strainer and other components.
  

The 412B and International Harvester’s Loader Legacy
The International 412B was part of a series of articulated wheel loaders produced during the 1980s, designed for municipal, construction, and aggregate operations. With an operating weight of approximately 28,000 pounds and powered by a turbocharged diesel engine producing around 160 horsepower, the 412B offered robust performance in material handling and site preparation. Its articulated frame and gooseneck-style loader arms allowed for tight maneuvering and high breakout force, making it a popular choice for gravel pits and road crews.
International Harvester, later reorganized as Navistar, had a long history of building durable off-road equipment. The 412B was engineered with mechanical simplicity and serviceability in mind, but like many machines of its era, it relied heavily on bronze and steel bushings to manage wear in pivot points—especially in the gooseneck assembly.
Understanding Gooseneck Geometry and Bushing Function
The gooseneck on the 412B refers to the curved loader arm section that connects the front frame to the lift arms and bucket linkage. It pivots at the base and at the bucket end, transferring hydraulic force into lifting and dumping motion. Bushings are installed at these pivot points to reduce friction, absorb shock, and maintain alignment between moving parts.
Typical bushing locations include:

• Lower gooseneck pivot at the front frame
  
• Upper gooseneck pivot at the lift arm connection
  
• Bucket linkage pivots and tilt cylinder mounts
  
• Articulation joint bushings (separate from gooseneck but often serviced together)
  

• Excessive movement or clunking during lift and dump
  
• Uneven bucket tilt or misaligned cutting edge
  
• Hydraulic cylinder side-loading and seal wear
  
• Grease leakage or dry pivot points
  
• Cracking or elongation of bushing housings
  

• Raise bucket and secure with safety prop
  
• Use pry bar to check for lateral movement at pivots
  
• Measure pin-to-bushing clearance with feeler gauges
  
• Inspect grease fittings and flow during lubrication
  
• Check for metal shavings or discoloration in grease
  

• Remove bucket and lift arms if necessary for access
  
• Support gooseneck with jack stands or crane
  
• Extract pivot pins using hydraulic press or puller
  
• Press out old bushings with bushing driver or custom mandrel
  
• Clean bore and inspect for scoring or distortion
  
• Install new bushings with press fit or adhesive as required
  
• Reinstall pins and torque to spec
  
• Lubricate thoroughly and test movement
  

• 20-ton hydraulic press or portable bushing press
  
• Bushing driver set with correct diameter
  
• Bore gauge for measuring housing wear
  
• Anti-seize compound for pin installation
  
• High-pressure grease gun with flexible hose
  

• Bronze: Traditional choice, good wear resistance and grease retention
  
• Nylon or UHMW: Lower friction, self-lubricating, but less load capacity
  
• Steel-backed composite: High load rating, long life, often used in OEM rebuilds
  
• Graphite-impregnated bronze: Ideal for dry or high-temperature environments
  

• Install grease grooves or spiral channels for better distribution
  
• Use split bushings for easier field replacement
  
• Add wear indicators or grease flow sensors
  
• Retrofit hardened pins with chrome plating for longer life
  

• Grease all pivot points weekly during active use
  
• Use high-quality lithium or moly-based grease
  
• Inspect for movement or noise monthly
  
• Replace bushings every 2,000 hours or as needed
  
• Keep pivot pins clean and free of rust
  

• Install remote grease lines for hard-to-reach pivots
  
• Add protective boots or shields around exposed bushings
  
• Use torque indicators on pivot bolts
  
• Document bushing wear during annual inspections
  

Skid steer loaders, such as the Gehl 5640, are integral pieces of equipment in construction, landscaping, agriculture, and a range of other industries. They are known for their compact size, versatility, and powerful performance in tight spaces. However, like all machinery, they can experience operational issues that affect productivity. Proper maintenance and troubleshooting are essential for keeping these machines running smoothly. One of the most common problems that owners and operators face is hydraulic issues or malfunctioning control systems. This article will explore how to troubleshoot common issues with a Gehl 5640 skid steer loader and offer practical solutions.
Common Problems with Gehl 5640 Skid Steer Loaders
The Gehl 5640, a popular model in the Gehl skid steer line, is designed to handle various tasks efficiently. However, users have reported a range of problems that can compromise performance. These issues often stem from hydraulic system failures, electrical glitches, or mechanical malfunctions.
1. Hydraulic System Failures
Hydraulic issues are among the most commonly reported problems in skid steer loaders, including the Gehl 5640. The loader’s hydraulic system powers many of its functions, including lifting, tilting, and turning. A malfunctioning hydraulic system can make the machine difficult to operate and lead to expensive repairs.
Symptoms of hydraulic issues:

• Slow or unresponsive lift arms
  
• Weak or no movement when engaging the loader bucket
  
• Overheating or noisy hydraulic pump
  
• Leaks in hydraulic lines or components
  

• Low fluid levels: Insufficient hydraulic fluid can cause the system to lose power and even damage the pump.
  
• Contaminated fluid: Dirt or debris in the hydraulic system can lead to clogs, inefficient fluid movement, and wear on the pump and valves.
  
• Faulty hydraulic pump or motor: Over time, the hydraulic pump or motor may wear out, causing a reduction in hydraulic pressure or complete failure.
  

• Always maintain the recommended hydraulic fluid levels and regularly inspect for leaks.
  
• Replace hydraulic fluid and filters every 500 hours or as recommended by the manufacturer.
  
• Clean or replace hydraulic hoses and fittings as needed to prevent blockages or leaks.
  
• If the hydraulic pump is faulty, it should be replaced or repaired by a qualified technician.
  

• Engine stalls or struggles to start
  
• Loss of power during operation
  
• Black smoke from the exhaust
  
• Unusual engine noise or vibration
  

• Clogged fuel filters: Over time, dirt and debris can clog the fuel filter, reducing the amount of fuel delivered to the engine.
  
• Fuel pump failure: The fuel pump may wear out or become damaged, leading to insufficient fuel flow to the engine.
  
• Faulty fuel injectors: A malfunctioning injector can lead to poor fuel atomization, causing rough engine operation and decreased efficiency.
  

• Check and replace the fuel filter regularly to prevent blockages.
  
• Inspect the fuel pump for signs of wear or damage, and replace it if necessary.
  
• Clean or replace fuel injectors that are clogged or malfunctioning.
  
• If the engine continues to struggle, consult a technician to diagnose deeper issues with the ignition or electrical system.
  

• Difficulty starting the engine
  
• Flashing warning lights or error codes on the display
  
• Non-functioning attachments
  
• Dead battery or intermittent power loss
  

• Battery problems: A dead or weak battery can prevent the machine from starting or cause intermittent power loss.
  
• Loose or corroded electrical connections: Over time, electrical connections can become loose or corroded, causing short circuits or power loss.
  
• Faulty alternator: If the alternator is not charging the battery properly, it can lead to electrical failures.
  

• Check the battery and terminals for corrosion, cleaning or replacing them if needed.
  
• Inspect and tighten all electrical connections, especially those near the alternator, battery, and starter motor.
  
• Test the alternator to ensure it is charging the battery properly. If it’s faulty, replace it.
  
• If the electrical issues persist, consult a technician for further diagnostics.
  

• Unresponsive or jerky bucket movements
  
• Inconsistent speed or direction of the skid steer
  
• Erratic arm or tilt function
  
• Control levers feeling loose or unresponsive
  

• Worn-out control cables or linkages: Over time, control cables and linkages may wear out, leading to poor response from the control levers.
  
• Faulty joystick or control valve: The joystick and valve system may become damaged or clogged, affecting responsiveness.
  
• Electrical issues: Sometimes, electrical faults in the control system can interfere with communication between the operator’s commands and the hydraulic system.
  

• Inspect control cables and linkages for wear and replace them if needed.
  
• Clean or replace the control valves and joysticks that are malfunctioning.
  
• Check for any electrical issues in the control system and repair any damaged wiring or connectors.
  

• Inspect and change filters regularly: Both air and fuel filters should be checked and replaced every 250 hours or according to the manufacturer’s recommendation.
  
• Check fluid levels: Maintain proper levels of hydraulic fluid, engine oil, and coolant to ensure the machine operates smoothly.
  
• Lubricate moving parts: Grease all moving components to reduce friction and prevent premature wear.
  
• Keep the machine clean: Regularly clean the undercarriage, hydraulic lines, and engine compartment to prevent dirt buildup, which can lead to overheating and wear.
  
• Pre-operation checks: Always perform a walk-around inspection before using the machine, checking for leaks, worn parts, and fluid levels.
  

The Lull 844B and Its Role in Material Handling
The Lull 844B is a rough-terrain telehandler designed for lifting and placing materials in construction, agriculture, and industrial settings. Manufactured under the Lull brand—later acquired by JLG—the 844B features a unique horizontal boom pivot system that allows precise load placement without repositioning the chassis. With a lift capacity of 8,000 pounds and a maximum reach of 44 feet, the machine became a staple on job sites requiring reach and stability.
Lull’s design philosophy emphasized operator control and mechanical simplicity. The 844B was powered by a diesel engine driving a hydraulic system that controlled boom extension, tilt, and auxiliary functions. At the heart of this system was a gear-type hydraulic pump, responsible for generating flow and pressure to actuate cylinders and motors.
Understanding Gear Pump Function and Seal Design
Gear pumps operate by trapping fluid between rotating gears and the pump housing, then forcing it through the outlet port under pressure. The Lull 844B typically uses a fixed-displacement gear pump mounted directly to the engine or transmission housing. These pumps are known for their durability and simplicity but rely heavily on internal and external seals to maintain pressure and prevent leakage.
Key sealing components include:

• Shaft seal: Prevents hydraulic fluid from leaking around the drive shaft
  
• Body-to-cover gasket: Seals the mating surfaces of the pump housing
  
• O-rings or lip seals around inlet and outlet ports
  
• Backup rings to prevent extrusion under high pressure
  
• Wear plates and bushings that maintain internal tolerances
  

• External fluid leaks at the pump flange or shaft
  
• Loss of hydraulic pressure or slow cylinder response
  
• Air intrusion causing foamy fluid or erratic movement
  
• Increased pump noise due to cavitation or wear
  
• Contaminated fluid from degraded seal material
  

• Clean pump exterior and monitor for fresh leaks
  
• Use pressure gauge to test output at control valve
  
• Inspect fluid for air bubbles or discoloration
  
• Remove pump and check shaft seal for cracks or hardening
  
• Measure housing flatness and gear wear for internal leakage
  

• Disconnect hydraulic lines and drain fluid
  
• Remove pump from engine or transmission mount
  
• Disassemble pump housing using proper tools
  
• Extract old seals with seal puller or pick
  
• Clean all surfaces with lint-free cloth and solvent
  
• Install new seals using seal driver or press
  
• Reassemble pump and torque bolts to spec
  
• Refill system and bleed air from lines
  

• Use OEM or high-quality aftermarket seal kits
  
• Match seal material to fluid type and temperature range
  
• Replace all seals during service, not just the failed one
  
• Inspect shaft for scoring and polish if needed
  
• Test pump on bench before reinstalling
  

• Change hydraulic fluid every 1,000 hours or annually
  
• Use filters with 10-micron rating or better
  
• Monitor fluid temperature and avoid overheating
  
• Inspect pump mounting bolts for vibration loosening
  
• Keep spare seal kits and gaskets in inventory
  

• Install fluid temperature sensor with cab alert
  
• Use magnetic drain plugs to detect wear particles
  
• Retrofit pump with external case drain to reduce seal pressure
  
• Add inline pressure gauge for real-time monitoring
  

When you purchase a new skid steer, you’re investing in a piece of machinery that will likely serve as the backbone of your operations for years. Whether you're using it in construction, landscaping, or agriculture, the skid steer is designed for tough tasks. However, like any heavy machinery, it needs to be properly broken in to ensure optimal performance, reliability, and longevity. Breaking in a new skid steer isn't just about easing it into work; it's about following the right steps to ensure the engine, hydraulic systems, and other components operate at their peak from day one.
Why is Break-In Important for New Skid Steers?
The break-in period for any new piece of equipment, including skid steers, is a crucial phase. This is when the moving parts, such as the engine, hydraulic system, and drive motors, begin to adjust to the pressures and friction of real-world operation. Failing to follow the proper break-in procedures can lead to excessive wear, reduced efficiency, and even premature failure of critical components.
During this period, the components are “seating” into their respective positions. The engine pistons are seating into the cylinder walls, the hydraulic seals are expanding to fit their grooves, and the tires or tracks are forming optimal contact with the ground. Without proper care during break-in, these components may experience uneven wear, affecting performance and longevity.
Key Aspects of a Proper Skid Steer Break-In
1. Follow Manufacturer Recommendations
Each skid steer model comes with specific guidelines from the manufacturer regarding break-in procedures. These guidelines include recommended hours of operation, speed limits, and load handling. Always refer to the owner’s manual for your specific model before starting the break-in process.
2. Initial Low-Load Operation
In the first 10 to 50 hours of operation, it’s important to use your skid steer at lower loads and speeds. Running the engine and hydraulics under full load or at high RPMs before the break-in period can cause excessive wear and tear. The primary goal is to allow the engine, transmission, and hydraulics to slowly adapt to the pressure they will face during heavy work.
For the first 10 hours, operate the skid steer under light to moderate loads. Avoid using heavy attachments or performing full-speed tasks like pushing large amounts of dirt or lifting heavy materials.
3. Vary the Operating Conditions
During the break-in period, it’s essential to vary the load, speed, and type of tasks your skid steer is performing. This allows all components to experience different conditions, helping them settle and adapt. Perform tasks such as light digging, lifting, and material handling to expose the machine to a variety of stresses. However, avoid prolonged periods of high-speed operation or running the machine at full throttle.
Varying the tasks during the break-in period helps ensure that all parts of the skid steer experience balanced wear, which is key to achieving long-term durability.
4. Monitor Engine Temperature and Fluids
During the break-in, closely monitor the engine temperature. Ensure the engine does not overheat, as this could indicate an issue with the cooling system or improper break-in procedures. Also, regularly check the oil levels, hydraulic fluid, and coolant. Low fluid levels can lead to overheating and increased wear, and old or dirty fluids can inhibit the break-in process.
Changing the oil after the first 50 hours of use is recommended. New engines often shed excess metal fragments during the first few hours of operation, and these can contaminate the oil. Changing the oil and filters ensures that contaminants are removed before they can damage critical components.
5. Gradually Increase Load
After the first 50 hours, begin to gradually increase the load and speed. This helps ensure that the machine is fully adapted to heavier workloads. At this stage, you can begin to use attachments such as buckets or forks, but you should still avoid operating the machine at full capacity for extended periods. Gradually working up to the full load allows the machine to continue adapting without overwhelming the components.
6. Frequent Checks and Servicing
During the break-in process, frequent checks and servicing are essential. Regularly inspect all components, including:

• Tires or Tracks: Check for proper inflation or tension, as they can wear unevenly during the break-in period.
  
• Engine Oil and Hydraulic Fluid: Monitor fluid levels, cleanliness, and any signs of leaks or excessive wear.
  
• Cooling System: Ensure the radiator and cooling systems are functioning properly, especially during the initial hours of operation when the engine is still adapting.
  

1. Overloading the Machine Too Soon: Pushing the skid steer too hard during the initial hours can cause premature wear, particularly in the engine and hydraulics.
   
2. Ignoring the Manufacturer’s Instructions: Every skid steer is unique, and ignoring specific break-in recommendations can lead to poor performance or damage. Always consult the manufacturer’s manual.
   
3. Skipping Fluid Changes: Not changing the oil and hydraulic fluid after the first 50 hours of operation can result in contamination that can cause long-term damage to the engine and hydraulic system.
   
4. Operating at High Speeds: Running a skid steer at full speed without allowing it to properly break in can result in excess strain on the engine, leading to overheating and decreased performance.
   

• Excessive Engine Wear: Without proper seating of the pistons and rings, the engine can wear prematurely, leading to reduced performance and potential engine failure.
  
• Hydraulic Failures: Hydraulic systems rely on seals and components that need time to form optimal contact. Rushing this process can cause leaks, reduced efficiency, and increased maintenance costs.
  
• Reduced Fuel Efficiency: A machine that’s not properly broken in will likely operate less efficiently, leading to increased fuel consumption and higher operational costs.
  
• Shorter Equipment Lifespan: The cumulative effect of not breaking in a skid steer properly will be a significantly reduced lifespan of the machine, leading to more frequent repairs and part replacements.