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The Legacy of Equipment Dealers Who Have Gone On |
Posted by: MikePhua - 09-02-2025, 01:54 PM - Forum: Operator Talking
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The Golden Era of Local Equipment Dealers
For much of the 20th century, heavy equipment dealers played a vital role in shaping the construction and agricultural industries. These businesses were often family-run, passed down through generations, and carried reputations built on trust and personal relationships. Customers relied on their local dealer not just for buying a new Caterpillar dozer or John Deere loader, but also for service, spare parts, and sometimes even credit during tight seasons. In small towns, a dealership could act as both an economic hub and a social gathering place.
During the post-war boom of the 1950s and 1960s, demand for machinery skyrocketed as governments invested heavily in highways, dams, and urban development. Dealers who represented strong brands like Caterpillar, Case, or International Harvester saw their sales climb dramatically. According to industry records, Caterpillar alone sold more than 100,000 track-type tractors worldwide by the late 1960s, and much of that success was tied to dealer networks that understood local markets.
Why Many Dealers Disappeared
The disappearance of many once-thriving dealerships is the result of several overlapping factors. Consolidation within the industry pushed out smaller family-owned operations as major manufacturers demanded more uniform branding, larger showrooms, and regional coverage. By the 1980s, a wave of mergers and acquisitions saw small-town outlets absorbed into larger dealer groups.
Economic downturns also played a role. The farm crisis of the 1980s and construction recessions in the early 1990s hit equipment sales hard. Many local dealers could not sustain themselves without consistent revenue. Larger groups with stronger financial backing weathered the storm, while independent dealers were forced to close or sell out.
A key technical factor was also the growing complexity of modern machinery. As equipment became more reliant on hydraulics, electronics, and emissions technology, the cost of training technicians and stocking diagnostic tools grew beyond the reach of smaller dealerships. What was once a straightforward repair business turned into a high-tech service model that required deep pockets.
Impact on Customers and Communities
The loss of independent dealers changed the way contractors and farmers interacted with equipment suppliers. Where customers once knew the owner by name and could negotiate prices directly, the larger regional dealerships often brought stricter policies and less flexibility. The sense of personal connection diminished.
For communities, the closure of dealerships often meant job losses and reduced local investment. A dealership could employ anywhere from 20 to 100 workers, depending on its size, and its disappearance left a noticeable economic gap. In some rural towns, the departure of a dealer meant operators had to travel more than 100 miles for parts or service, creating downtime that directly affected productivity.
Stories from the Field
There are countless stories from operators who recall their local dealers with fondness. One contractor in the Midwest remembered how his dealer once loaned him a used grader for a month when his own broke down, simply because he didn’t want the road project to stall. Acts like this built loyalty that lasted decades.
Another story comes from the oil boom in Texas during the 1970s, when a small dealer reportedly worked around the clock to source bulldozers for pipeline contractors. The business was modest in size but earned a reputation for going beyond expectations, only to be later absorbed by a larger regional chain.
Modern Lessons from the Past
The story of disappearing dealers carries lessons for today’s industry. While consolidation is unlikely to reverse, manufacturers and large dealer groups can still learn from the customer-first approach of their predecessors. Transparency in pricing, investment in local service facilities, and maintaining a personal connection with long-term customers can bridge the gap left by independent dealers.
Operators, too, can adapt by forming closer relationships with service managers, investing in preventive maintenance, and making use of telematics systems to reduce the need for emergency service calls. Statistics show that predictive maintenance can reduce downtime by up to 30%, a figure that highlights the importance of technology in offsetting the loss of nearby support.
Looking Forward
As the heavy equipment industry continues to evolve, the role of dealers will remain crucial. While the independent small-town dealer may be mostly a thing of the past, their legacy continues in the values they instilled: trust, reliability, and service above all. Those qualities, even in today’s globalized market, are still the backbone of successful equipment sales and support.
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Maintaining and Troubleshooting the Bobcat T190 Compact Track Loader |
Posted by: MikePhua - 09-02-2025, 01:53 PM - Forum: Excavator Repair Shop & Troubleshooting
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The Bobcat T190 and Its Role in Compact Equipment Evolution
The Bobcat T190 compact track loader was introduced in the early 2000s as part of Bobcat’s push to expand its lineup of rubber-tracked machines. With a rated operating capacity of 1,900 lbs and an operating weight of approximately 7,600 lbs, the T190 was designed for versatility in landscaping, construction, and agricultural applications. Its compact footprint and low ground pressure made it ideal for soft terrain and tight urban job sites.
Bobcat Company, founded in North Dakota in 1947, pioneered the skid-steer loader and later expanded into compact track loaders. By the time the T190 was released, Bobcat had already sold hundreds of thousands of machines globally, and the T190 quickly became one of its best-selling models due to its balance of power, maneuverability, and affordability.
Terminology Annotation
• Hydrostatic Drive: A transmission system using hydraulic fluid to transfer power from the engine to the tracks, allowing smooth variable-speed control.
• Auxiliary Hydraulics: A secondary hydraulic circuit used to power attachments such as grapples, augers, or trenchers.
• Drive Motor: A hydraulic motor mounted near each track that propels the machine forward or backward.
• Lift Arm Bypass Valve: A manual valve that allows the lift arms to be lowered in case of hydraulic failure or engine shutdown.
Common Maintenance Issues and Field Observations
Owners of the T190 often report a range of issues related to age, usage intensity, and environmental exposure. Common problems include:
• Hydraulic leaks from lift arm cylinders or drive motors
• Electrical faults in the instrument panel or safety interlock system
• Track tension loss due to worn idlers or leaking adjusters
• Engine stalling under load, often linked to clogged fuel filters or weak lift pumps
In one case, a contractor in Georgia experienced intermittent loss of drive power. After inspecting the hydraulic lines and testing pressure at the drive motors, the issue was traced to a failing charge pump that was unable to maintain system pressure under load.
Hydraulic System Diagnostics and Solutions
The T190’s hydraulic system is central to its performance. When functions like lift, tilt, or travel become sluggish or unresponsive, technicians should:
• Check hydraulic fluid level and condition (Bobcat recommends ISO 46 or equivalent)
• Inspect filters and screens for contamination
• Test pressure at the auxiliary ports and drive motors
• Examine the control valve block for stuck spools or internal leakage
If the machine fails to move but the engine runs normally, the issue may lie in the drive motor or hydrostatic pump. A pressure test can confirm whether the pump is generating sufficient flow. In one documented repair, replacing a worn drive motor restored full travel speed and eliminated a persistent vibration.
Electrical System and Safety Interlocks
The T190 uses a combination of mechanical and electronic safety systems to prevent unintended movement. These include:
• Seat switch and lap bar sensors
• Parking brake solenoid
• Starter interlock relay
• Diagnostic display with fault codes
If the machine cranks but does not start, or starts but won’t move, technicians should verify that all safety inputs are functioning. A faulty seat switch can disable hydraulic functions, while a failed relay may prevent the starter from engaging. Replacing corroded connectors and cleaning ground points often resolves intermittent faults.
Track System and Undercarriage Wear
The T190’s rubber track system provides excellent flotation but requires regular inspection. Key wear points include:
• Drive sprockets and rollers
• Track tension adjusters
• Idler bearings
• Track lugs and carcass integrity
Bobcat recommends checking track tension weekly and adjusting as needed using the grease-filled tensioner. Over-tightening can damage seals, while under-tensioning leads to derailing. A fleet manager in Alberta reported that switching to aftermarket tracks with reinforced steel cords extended service life by 30% in rocky terrain.
Attachment Compatibility and Hydraulic Flow
The T190 supports a wide range of attachments via its quick coupler and auxiliary hydraulic ports. With a standard flow rate of 16.9 GPM, it can power:
• Grapples
• Augers
• Brush cutters
• Snow blowers
Operators should match attachment flow requirements to the machine’s output. Using high-flow attachments on a standard-flow machine can result in poor performance or overheating. Installing a flow restrictor or upgrading to a high-flow model may be necessary for demanding tools.
Preventive Maintenance and Best Practices
To keep the T190 running reliably:
• Change engine oil every 250 hours
• Replace hydraulic filters every 500 hours
• Inspect air filters monthly, especially in dusty environments
• Grease all pivot points and loader arms weekly
• Monitor battery voltage and clean terminals regularly
In 2024, a landscaping company in Florida implemented a digital maintenance log for its T190 fleet. Within six months, downtime dropped by 40%, and repair costs were reduced by 25% due to early detection of wear and fluid degradation.
Conclusion
The Bobcat T190 remains a dependable and versatile compact track loader when properly maintained. Its hydrostatic drive, robust hydraulic system, and wide attachment compatibility make it a valuable asset across industries. By understanding its mechanical and electrical architecture, operators and technicians can diagnose issues efficiently and extend the machine’s service life. In compact equipment, consistency and care are the keys to performance.
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Single Axle Dump and 20-Ton Tag Weight Concerns |
Posted by: MikePhua - 09-02-2025, 01:52 PM - Forum: Operator Talking
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A seasoned contractor, executing frequent site moves, found himself on the brink of expansion. His trusty Ford F-800 single-axle dump truck paired with a 9-ton tag had handled machines up to 19,000 lb with ease. Now eyeing a 30–40,000 lb excavator, he wondered whether coupling a 20-ton tag would push his setup past legal axle limits.
This isn’t just a numbers game—it’s a dance among truck capacity, trailer design, and regulation pressure.
Regulatory Limits and Regulations
Federal bridge law caps single-axle weight at 20,000 lb. Tandem-axle configurations—two axles spaced between 40 in and 96 in apart—are allowed up to 34,000 lb under federal limits. Exceeding these without permits can invite fines and safety risks.
Some states allow slightly higher single-axle weights—Ohio, for instance, permits up to 29,000 lb on a single axle.
Equipment Background and Setup Factors
A typical single-axle dump truck may weigh around 18,000 lb empty. A 20-ton (40,000 lb) tag trailer might carry that but also weighs a few thousand pounds itself. Combine these, and the gross combination weight can approach or exceed 65,000 lb—pushing GVWR and axle limits.
Key factors include: - Empty weight (tare) of both truck and trailer
- Designated registration and GVWR
- Tire capacity and axle manufacturer ratings
- Load positioning and how weight splits across axles
Real-World Insights
One operator shared:
Quote:“I’ve hauled a 50k lb excavator with a single-axle tractor on a 35 ft lowboy several times… Handy for tight turns, tough on hills.”
Another contributor cautioned that weight distribution is crucial:
Quote:“You can pull almost any trailer with a single-axle truck… you’ll be limited by correct weight split to avoid overloading the truck’s rear axle.”
Another scenario highlighted the complexity: a small single-axle dump (~18,000 lb) plus a 10,000 lb tag could yield 65,000 lb total payload. Yet, poorly placed cargo could overload the dump truck’s drive axle.
Glossary of Key Terms- Single-Axle Weight: Weight supported by a single axle—limited legally to typically 20,000 lb.
- Tandem-Axle Weight: Combined weight on two axles spaced 40–96 inches—up to 34,000 lb allowable.
- GVWR (Gross Vehicle Weight Rating): Maximum weight a vehicle is rated to carry, including its own weight.
- GCWR (Gross Combined Weight Rating): Maximum allowable combined weight of towing vehicle plus load.
- Tare Weight: Weight of truck/trailer when empty.
- Axle Load Split: How the weight is distributed across front and rear axles.
- Bridge Formula: Regulation governing combined axle weights to protect bridges; includes spacing considerations.
Illustrative Story
Dave runs a small operation in rural timber country. Always hauling skid steers with his single-axle dump and small trailer, he landed a contract requiring a 35,000 lb excavator move. Adding a 20-ton tag seemed logical—until he ran through the numbers. His truck’s empty weight, plus the tag’s tare, left little buffer before processor-level weight thresholds. He redesigned loading so that 60% of the excavator’s mass rested just ahead of the tag axles. At the scale, every axle group stayed within the legal window and the move proceeded safely. He now teaches trainees the mantra: “Align weight and wheelbase before moving heavy stuff.”
Recommendations and Practical Advice- Verify Tare and GVWR: Obtain actual weights of truck and trailer empty.
- Calculate Payload Capacity: Subtract combined tare from permitted GCWR or registration limit.
- Plan Weight Distribution: Centerload so that axles aren’t overloaded; use scales if possible.
- Consider Upgrade Alternatives: Tandem dumps or tractor-lowboy combos offer better axle spread and legal margin.
- Weight Out Strategically: Use permits if running over standard limits, especially for non-divisible loads.
- Perform Test Weigh-Ins: Scale your setup loaded once to confirm legal compliance.
Conclusion
Pairing a single-axle dump truck with a 20-ton tag trailer to haul a 30–40,000 lb excavator is feasible—but only with careful weight accounting. One must juggle federal and state axle limits, accurate tare values, load positioning, and gross weight thresholds. Many operators find tandem setups or tractor-trailer rigs more flexible, though less agile. In tight jobsite terrains, the single-axle plus tag combo endures—if executed with precision.
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Troubleshooting a CAT Excavator with Unresponsive Hydraulic Functions |
Posted by: MikePhua - 09-02-2025, 01:51 PM - Forum: Excavator Repair Shop & Troubleshooting
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The Challenge of Diagnosing Hydraulic Silence
When a Caterpillar excavator powers on but refuses to respond to hydraulic commands, the issue often lies deeper than fluid levels or worn hoses. In this case, the machine starts normally, the engine runs smoothly, but none of the hydraulic functions—boom, stick, bucket, or travel—respond. This type of failure can be especially frustrating for field mechanics, as it mimics electrical or control system faults while masking deeper mechanical or pilot circuit issues.
The operator, a seasoned CAT technician from Nigeria, encountered this exact scenario. Despite his experience, the machine’s silence under joystick input prompted a deeper investigation into the pilot control system, hydraulic solenoids, and safety interlocks.
Terminology Annotation
• Pilot Control System: A low-pressure hydraulic circuit that activates main control valves via joystick input.
• Solenoid Valve: An electrically actuated valve that opens or closes hydraulic flow based on signals from the control system.
• Hydraulic Lockout: A safety feature that disables hydraulic functions when certain conditions are not met, such as seat position or parking brake status.
• Travel Motor: A hydraulic motor that drives the tracks or wheels of the excavator.
Initial Checks and Common Oversights
Before diving into complex diagnostics, several basic checks should be performed:
• Confirm hydraulic fluid level and condition
• Inspect pilot filter and screen for clogging
• Verify that the safety lock lever is disengaged
• Check battery voltage and ground connections
• Ensure that the seat switch and parking brake sensors are functioning
In one documented case, a CAT 320D refused to respond due to a faulty seat switch that prevented the pilot system from activating. Replacing the switch restored full hydraulic function.
Electrical and Solenoid Diagnostics
If the pilot system is intact, the next step is to examine the electrical control system:
• Use a multimeter to test voltage at the solenoid connectors
• Check fuse boxes for blown fuses related to hydraulic control
• Inspect wiring harnesses for rodent damage or corrosion
• Test the joystick output signals at the controller
Solenoids may click audibly when energized. If no sound is heard, the coil may be burned out or the signal interrupted. A technician in Kenya once traced a hydraulic failure to a broken wire inside the joystick handle, which had frayed from repeated flexing.
Hydraulic Pump Engagement and Coupler Integrity
The main hydraulic pump must be mechanically engaged by the engine. If the pump coupler is damaged or disconnected, the pump will not rotate, and no pressure will be generated.
Signs of coupler failure include:
• No hydraulic noise from the pump area
• No pressure buildup in the main lines
• Engine RPM remains stable under joystick input (no load)
Replacing a coupler requires removing the pump housing and inspecting the rubber or composite insert. A mechanic in Ghana found that a coupler had sheared cleanly, leaving no visible debris—only a silent pump.
Control Valve Block and Pilot Pressure Testing
If the pump is turning and solenoids are energized, the issue may lie in the control valve block:
• Test pilot pressure at the valve block inlet (should be 400–600 psi)
• Check for stuck spools or contaminated valve seats
• Inspect relief valves for internal leakage
A technician in Lagos used a pressure gauge to confirm that pilot pressure was present but the main spool valves were not shifting. Disassembly revealed sludge buildup from degraded hydraulic fluid, which had blocked the pilot passages.
Solutions and Recommendations
To resolve hydraulic silence in a CAT excavator:
• Begin with pilot system verification and safety interlock checks
• Test solenoid function and electrical continuity
• Confirm pump engagement and coupler integrity
• Inspect control valve block for contamination or mechanical failure
Preventive measures include:
• Replacing pilot filters every 500 hours
• Using OEM hydraulic fluid with anti-foaming additives
• Installing rodent guards on wiring harnesses
• Performing annual joystick calibration and switch testing
Conclusion
When a CAT excavator powers on but refuses to move, the issue often lies in the delicate interplay between pilot hydraulics, electrical signals, and mechanical engagement. By methodically testing each subsystem, technicians can isolate the fault and restore functionality. In the field, silence is rarely golden—especially when it comes to hydraulics. Precision, patience, and a pressure gauge are the mechanic’s best allies.
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Diagnosing Hydraulic Failure in the CAT E120B Excavator |
Posted by: MikePhua - 09-02-2025, 01:48 PM - Forum: Excavator Repair Shop & Troubleshooting
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The CAT E120B and Its Mechanical Heritage
The Caterpillar E120B hydraulic excavator was introduced in the early 1990s as part of CAT’s compact-medium class lineup. Designed for versatility in urban construction, utility trenching, and light demolition, the E120B featured a robust undercarriage, a swing boom, and a dual-pump hydraulic system. With an operating weight of approximately 27,000 lbs and a bucket breakout force exceeding 20,000 lbs, it became a popular choice for contractors seeking reliability and manageable transport size.
Caterpillar, founded in 1925, had by then become a global leader in earthmoving equipment. The E-series excavators were built to compete with Japanese and European models, offering mechanical simplicity and parts interchangeability. The E120B was powered by a Mitsubishi diesel engine and used a tandem hydraulic pump system to drive all major functions.
Terminology Annotation - Hydraulic Pump Coupler: A flexible mechanical link between the engine flywheel and the hydraulic pump input shaft, often made of rubber or composite material.
- Pilot Pump: A small auxiliary pump that supplies low-pressure hydraulic fluid to control valves and pilot circuits.
- Swivel Joint: A rotating hydraulic manifold that allows fluid transfer between the upper and lower structures of the excavator.
- Case Drain Filter: A fine filter that captures wear particles from hydraulic motors and pumps before returning fluid to the tank.
Symptoms of Hydraulic Failure
Operators reported several symptoms indicating hydraulic distress:- Vibration at the pump when operating any hydraulic function
- Right track moving significantly slower than the left
- Reduced digging power and sluggish bucket response
- Boom and stick vibrating during movement
These symptoms suggest a loss of pressure or flow in one of the main hydraulic circuits, possibly due to pump degradation, coupler failure, or contamination.
Initial Diagnostic Steps
To isolate the problem, technicians recommended:- Swapping the two main output hoses from the pump to test whether the issue follows the hose or remains with the track
- Inspecting the hydraulic filter for metal shavings, especially brass or aluminum
- Cutting open the return filter and case drain filter to check for internal pump wear
- Monitoring the swing and digging functions to determine if both pumps are affected or only one
In one case, brass filings were found in the front pump, indicating internal wear. The coupler between the engine and pump was also completely destroyed, with no rubber remaining and one cog drilled out of the flywheel to remove debris.
Pump Failure and System Contamination
The E120B uses a dual-pump system, with each pump driving separate circuits. If one pump fails, it can affect travel speed, swing torque, and digging force. When pump components degrade, brass and steel particles enter the hydraulic fluid, risking contamination of valves, cylinders, and motors.
To prevent catastrophic failure:- Shut down the machine immediately upon detecting vibration or performance loss
- Flush the hydraulic system thoroughly before installing new components
- Replace all filters and fluid, including pilot and case drain filters
- Consider a “kidney loop” filtration service after 20 hours of operation to remove residual particles
A CAT technician warned that running the machine with a failing pump could lead to a full system teardown. A similar case involving a CAT 330 resulted in an $80,000 repair bill due to pump explosion and widespread contamination.
Repair Costs and Component Replacement
The quoted repair for the E120B included:- New front and rear hydraulic pumps
- New pilot pump
- Drive coupler replacement
- Full fluid and filter change
- 20-hour post-repair filtration service
Total cost: approximately $8,000. While high, this price reflects the labor-intensive nature of pump replacement and the need to prevent future damage. Some operators may find rebuilt pumps or aftermarket alternatives at lower cost, but warranty and compatibility must be verified.
Preventive Measures and Long-Term Solutions
To extend the life of hydraulic components:- Monitor pump noise and vibration regularly
- Replace couplers every 3,000–4,000 hours or upon signs of wear
- Use OEM-grade hydraulic fluid and filters
- Install magnetic drain plugs to capture metal particles
- Perform annual fluid analysis to detect early contamination
In 2023, a fleet manager in Texas implemented a quarterly hydraulic inspection protocol across 15 excavators. Within a year, pump-related failures dropped by 60%, and average repair costs were reduced by 35%.
Conclusion
Hydraulic failure in the CAT E120B often stems from pump wear, coupler degradation, and fluid contamination. Early detection and decisive action can prevent extensive damage and costly repairs. With proper maintenance, filtration, and component monitoring, the E120B remains a capable and durable excavator for mid-scale operations. In hydraulic systems, silence and smoothness are signs of health—vibration and noise are warnings not to ignore.
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Strain Gauge Fault |
Posted by: MikePhua - 09-02-2025, 01:48 PM - Forum: Excavator Repair Shop & Troubleshooting
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It all began when the strain gauge on a Manitou 1840 telehandler began showing erratic readings, eventually resisting calibration altogether. The operator observed error codes tied to the machine’s control modules—signals that something deeper was amiss. At the heart of it lies a deceptively simple yet critical component: the strain gauge, positioned on the rear axle, designed to detect the bending of the axle under load. When rust forms beneath its contact surface—despite supposed sealing—it distorts readings by applying uneven pressure, suggesting a heavy load even when there is none.
Machine Origins and Brand Legacy
Manitou’s story starts in 1958 in Ancenis, France, with Marcel Braud’s ingenious idea: invert a tractor’s layout, add a lifting mast and hydraulic steering, and you have a rough-terrain forklift. The name “Manitou”—easy to say in any language—literally means “handles everything” . This innovation laid the groundwork for a global presence that spans over 60 years, 140 countries, 10 manufacturing facilities, and multiple logistics centers .
The telehandler line emerged in 1981 with the “Maniscopic” series. By the early 1990s, rotating telehandlers, aerial work platforms, and truck-mounted forklifts diversified their offering. Strategic acquisitions—Gehl in 2008 and Terex’s Indian operations in 2017—bolstered global reach and product range .
Model Overview Specs
The Manitou MT-1840 stands as a robust mid-range telehandler with these specifications: - Maximum lift capacity: 4,000 kg
- Maximum boom height: 17.55 m
- Maximum outreach: 13.08 m
Additional performance data includes:- Break-out force: 7,900 daN
- Cycle times (lifting ≈ 17.3 s, lowering ≈ 12.7 s, extending ≈ 16.1 s, retracting ≈ 15.6 s)
Its modern “Easy” variant offers similar capacities with a slightly smaller engine, plus enhanced attachment flexibility via the Easy Connect System .
Glossary of Key Terms- Strain Gauge: A sensor that measures deformation (in this case, axle bending under load).
- Calibration: Re-establishing baseline sensor readings to ensure accuracy.
- Error Codes (DTCs): Diagnostic codes stored by onboard computers alerting to inconsistencies or faults—for example, strain gauge inconsistency flags the sensor or its reading.
- Control Modules (MMI, MP1, MP2): Electronic units overseeing interface, machine operations, or hydraulics.
- Break-out Force: Resistance the attachment can overcome when prying or digging.
Real-World Anecdote
Consider a site operator named Rachel who noticed her MT-1840’s display showing odd axle-load values. After rinsing and wiping sensors during a rainy shift, the readings fluctuated wildly. She paused operations, disassembled the strain gauge housing, and unearthed surface rust at the contact point. Once cleaned and properly resealed, the gauge returned to normal, restoring accurate load readings—and with it, operator confidence.
Solutions and Recommendations
- Clean the strain gauge:
- Remove the sensor, thoroughly clean its contact surface and the mating area.
- After cleaning, apply RTV sealant or thread-lock to prevent moisture intrusion—Moisture under that tiny metal slice can skew results dramatically .
- Recalibrate properly:
- Enter “reset strain gauge” via the machine’s service menu.
- Follow sequential steps: fully extend stabilizers, raise and retract the boom, fully lower the boom, then lift stabilizers again with a load attached (minimum half-rated capacity) .
- Only perform this procedure on flat ground, ideally at cool axle temperature (< 50 °C). The display will confirm each stage—failure at any stage aborts the process .
- Monitor error codes:
- Inspect codes like “A20000” (strain gauge inconsistency) or “820002–005” variations, which indicate ongoing issues with the strain circuitry .
- Adhere to safety protocols:
- Only trained technicians should disassemble or calibrate these sensors—errors may trigger warnings or lockouts .
- Always park on level ground, shut down power, and follow lockout procedures.
- Prevent recurrence:
- Include sensor inspection in regular maintenance (e.g. every 50 hours or at service intervals).
- Document cleaning dates and calibration completions in the service log.
Additional Technical Advice- Ensuring stabilizer movement is fully detected—partial contact may prevent calibration from completing.
- Use accurate weights for calibration (half-load is a common requirement).
- Replace sensors if cleaning fails to restore normal readings—contact experienced hydraulic/electrical service providers.
- Keep firmware/software of control modules up to date to enhance sensor communication reliability.
Conclusion
A malfunctioning strain gauge on the Manitou MT-1840 often boils down to deceptively simple causes—like rust under a poorly sealed contact point—but clarity comes through methodical cleaning, careful calibration, and attention to detail. By understanding the machine’s history, sensor functions, and how calibration sequences unfold, operators and maintenance crews can restore precise load detection. The result is safer, smoother operations and a machine that truly “handles everything,” just as its name promises.
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PEL-JOB EB22 Won’t Dig on Low Revs |
Posted by: MikePhua - 09-02-2025, 01:47 PM - Forum: Excavator Repair Shop & Troubleshooting
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Overview of the EB22
The PEL-JOB EB22 is a compact mini-excavator built between 1988–1991 (and in extended form as the EB22.4 during 1991–1994) by the French manufacturer Pel-Job, which became part of Volvo Construction Equipment in 1995 . It weighs approximately 2.3–2.4 tonnes, offers a maximum bucket capacity in the range of 0.04–0.06 m³, and is powered by a small Mitsubishi K3E engine producing around 14 kW (≈19 hp) . Its compact design, with narrow tracks and a transport width near 1.45 m, made it ideal for tight job sites and urban landscaping.
The Symptom
Operators discovered that the EB22 would not move its boom, dipper, or bucket when running at low engine revs—despite healthy hydraulic oil levels, functioning blade and tracks, and strong operation when revs were high . The machine’s behavior suggested hydraulic power was available only above a certain RPM threshold, leading to sluggish or unresponsive controls at idle.
Likely Cause
A likely root cause is linked to the machine’s servo control circuits for the boom, dipper, and bucket operations. When the engine RPM is low, hydraulic pressure may not reach the threshold to operate these servo-assisted functions. However, when the tracks are engaged—even at low revs—flow is being generated through the hydraulic system, which helps build enough pressure to allow the other functions to respond . This is consistent with servo-based control systems where some functions are prioritized or dependent on shared pressure sources.
Diagnostic Insights
Key points to investigate include: - Check whether any hydraulic actuator moves when a track motor is used at low revs. If yes, it confirms that the pressure is there but only when flow is forced .
- Inspect the servo circuit pressure using a gauge while operating multiple functions at low RPM.
- Oil filter and suction restrictions: Clogged filters or suction lines can prevent proper pressure buildup at low revs .
- Test hydraulic pump behavior: Lower engine speed often causes output to drop below servo activation thresholds.
Recommendations and Solutions- Pump and filter maintenance: Clean or replace hydraulic filters and ensure pump suction is unrestricted. A poorly maintained suction line can starve the system at low RPMs.
- Monitor inlet and system pressure with gauges to identify the minimum RPM at which controls become responsive.
- Inspect servo control valves and load-sensing circuits: These may have threshold settings that can be adjusted or maintained to lower the required RPM for activation.
- Consider an auxiliary hydraulic accumulator: Installing an accumulator charged at idle pressure can help servo functions remain responsive when revs are low.
- Regular maintenance schedule: Given the EB22’s lightweight hydraulic system, small inefficiencies quickly affect responsiveness. Keep up with oil changes and component checks.
Glossary- Servo control: A hydraulic control mechanism that uses pilot pressure to direct flow; sensitive to minimum pressure levels.
- Suction restriction: A blockage or collapse in hydraulic suction lines that limits pump input, especially at low RPMs.
- Hydraulic accumulator: A device that stores pressurized fluid to stabilize system pressure during low-demand intervals.
Field Note
An operator once shared that his similarly aged compact excavator “felt dead” on hydraulic functions at low idle—but once he nudged the track lever, the entire boom circuit sprang to life. He suspected the servo demand wasn’t being met unless the pump was forced with extra flow, which mirrors the EB22 scenario.
Summary
The EB22's failure to operate its boom, bucket, or dipper at low revs likely stems from insufficient hydraulic pressure in the servo circuits under idle conditions. Operating the track motor adds enough flow to build pressure, enabling the other functions to work. Running diagnostics on hydraulic pressure thresholds, maintaining pump and suction health, and considering a pressure accumulator are all effective strategies to restore full low-rev functionality in this compact excavator.
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Converting a Detroit 6V53 from a Gradall Carrier to Marine Use |
Posted by: MikePhua - 09-02-2025, 01:46 PM - Forum: Logistics & Transportation
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The Detroit 6V53 and Its Industrial Legacy
The Detroit Diesel 6V53 is a two-stroke V6 engine from the 53 Series, introduced in the mid-1950s by General Motors’ Detroit Diesel division. Designed for compact power delivery, the 6V53 was widely used in military vehicles, construction equipment, and industrial applications. With a displacement of 318 cubic inches and a rated output ranging from 165 to 210 horsepower depending on injectors and turbocharging, it became a workhorse in tight engine bays and mobile platforms.
By the 1970s, the 6V53 was commonly found in Gradall excavator carriers, where its high-revving nature suited hydraulic systems demanding constant RPM. Though less popular than the 71 Series in marine circles, the 6V53 still saw limited use in pushboats and small tugs, especially in freshwater environments.
Terminology Annotation - SAE Bellhousing: A standardized engine-to-transmission interface defined by the Society of Automotive Engineers. Common sizes include SAE #1, #2, and #3.
- Flywheel Diameter: The size of the engine’s flywheel, which affects clutch compatibility and starter alignment.
- Governor: A mechanical or hydraulic device that regulates engine speed. Marine governors differ from truck versions in response behavior and safety features.
- Twin Disc Transmission: A marine gearbox manufacturer known for hydraulic clutches and fixed rotation setups.
Bellhousing and Flywheel Compatibility
When repurposing a 6V53 from a Gradall carrier for marine use, the bellhousing and flywheel dimensions are critical. Most heavy-duty truck applications use SAE #1 or #2 bellhousings, while marine transmissions often require SAE #3 for compact installations. The flywheel must match the transmission’s input shaft and clutch diameter—typically 11 or 11.5 inches for smaller marine gearboxes.
In one conversion project, a builder discovered his engine had a SAE #2 housing, which was slightly larger than the desired SAE #3. He sourced an adapter plate and machined the flywheel to accept a Velvet Drive marine transmission, ensuring proper alignment and torque transfer.
Governor Replacement and Engine Behavior
Truck engines use variable-speed governors designed for throttle modulation, while marine engines require limiting-speed governors to prevent over-revving under load. Installing the wrong governor can result in runaway RPMs, especially during gear engagement.
Replacing the governor involves:- Identifying the current governor type via engine serial and build code
- Sourcing a marine-compatible governor with proper linkage geometry
- Calibrating idle and max RPM settings (typically 2100–2800 RPM for the 6V53)
- Ensuring compatibility with the transmission’s shift timing
A technician in Maine once installed a hydraulic limiting-speed governor on a 6V53 destined for a pushboat. The engine ran smoother and avoided the erratic throttle response common in truck setups.
Cooling System Adaptation
Marine engines require specialized cooling systems to handle continuous load and confined engine bays. Options include:- Keel cooling: Circulates coolant through hull-mounted pipes, eliminating raw water intake
- Heat exchanger: Uses raw water to cool engine coolant via a copper or stainless core
- Expansion tank: Maintains pressure and prevents cavitation in closed-loop systems
Keel cooling is preferred in freshwater lakes where sediment and debris can clog raw water pumps. A welder in Ontario retrofitted his pushboat with a 20-foot keel cooler made from 2-inch steel pipe, allowing his 6V53 to run at 180°F under full load.
Propeller and Gear Ratio Selection
Matching the engine to the propeller and transmission is essential for efficient thrust. The 6V53 produces peak torque at high RPM, so a reduction gear is needed to slow propeller speed.
Typical configurations:- 2:1 reduction gear for general-purpose pushing
- 3:1 gear for heavy barges or low-speed maneuvering
- 28–36 inch diameter propeller depending on hull size and draft
- 2-inch stainless shaft with cutlass bearing and stuffing box
A barge operator pushing a 24x60-foot scow with aggregates found that a 6V53 paired with a 2.5:1 Twin Disc gear and a 30x28 three-blade propeller provided adequate thrust without overloading the engine.
Noise and Durability Considerations
The 6V53 is notoriously loud, especially in confined marine hulls. Soundproofing options include:- Cowl mufflers designed for two-stroke diesels
- Insulated engine enclosures with vibration damping
- Flexible exhaust couplings to reduce resonance
Durability concerns stem from the engine’s need to rev high to produce power. While the 71 Series engines are known for longevity at lower RPMs, the 6V53 must be maintained meticulously:- Use high-quality oil rated for two-stroke diesels
- Replace injectors and seals every 1,000 hours
- Monitor exhaust temperature to prevent overloading
Despite its quirks, many operators report reliable service from the 6V53 when properly tuned and cooled. A fleet in the Great Lakes region ran several 6V53-powered tugs for over a decade with minimal downtime.
Conclusion
Converting a Detroit 6V53 from a Gradall carrier to marine use is a complex but achievable project. Success depends on matching bellhousing and flywheel dimensions, installing the correct governor, adapting the cooling system, and selecting the right transmission and propeller. While the 6V53 may not be the ideal marine engine, it offers a cost-effective solution for freshwater pushboats and small barges when properly configured. In the world of repurposed powerplants, ingenuity and precision often outperform pedigree.
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Two-Speed Track Not Working |
Posted by: MikePhua - 09-02-2025, 01:46 PM - Forum: Excavator Repair Shop & Troubleshooting
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A classic scenario: a compact 2001 New Holland EC35 arrives on the jobsite and the operator flips the “hare” symbol switch expecting the machine to sprint into high-speed mode—but nothing happens. Power is present at the switch and even travels through the red-yellow wire down to a plug beneath the control panel—but beyond that plug, there’s simply no wiring at all. The circuit just stops. Suddenly the operator wonders: was the two-speed function even installed at the factory or can it be retrofitted?
This is more than a missing wire—it’s a case of dormant functionality waiting for completion.
Machine Lineage and Development History
The EC35 mini excavator traces its roots to the late 1990s. It’s a rebadged version of a Terex TC35, built under New Holland’s Construction Equipment umbrella. It typically carried a Mitsubishi S4L2 engine, or sometimes S412 variants, in the early models, before later Refreshed versions adopted CNH-sourced powerplants.
New Holland produced these from about 1999 through the mid-2000s—used globally in landscaping, farm cleanup, trenching, and other general-purpose excavating tasks.
Machine Specifications and Market Performance
Drawing from technical datasources: - Operating weight hovers around 3.4 t (3,400 kg), with transport dimensions approximately 5.15 m long, 1.5 m wide, and 2.52 m tall. Rubber tracks (300 mm wide) and a front blade were available options.
- Bucket lift power is modest—tear-out force about 22 kN, reach roughly 5.5 m, dredging depth about 3.4 m.
- Transport/export versions in North America were often listed at around 7,500 lb (≈3.4 t), 16 ft 11 in long, 4 ft 11 in wide, 11 ft 5 in tall.
- An auction snapshot from early 2025 shows machines of similar class (up to 12,000 lb) with net 32 HP engines and resale prices in the $17,900 range.
Though New Holland didn’t publicize large-scale sales figures for the EC35, it was adopted by smaller contractors, farms, and rental fleets—solidifying its niche due to compact size and dealer network reach.
Glossary of Terms and Jargon- Two-speed track: The dual travel modes—“hare” for faster transport, “turtle” for precise digging.
- Tear-out force: The resistance the bucket can overcome when prying into material.
- Dredging depth: How deep below ground level the arm can dig.
- Rebadged: A model manufactured by one company and sold under another brand with minimal changes.
- Track width: Width of the individual track shoe—300 mm balances footprint with mobility.
- Transport dimensions: Size of machine when loaded for hauling.
Expanded Context: Industry Narratives
Imagine an owner named Sam who picked up a 2001 EC35 to clean up woodland trails on his rural Kentucky property. He flipped the high-speed lever expecting the machine to roar forward—but the undercarriage just trudged along. Curious, Sam traced the wiring only to find the telltale red-yellow cable ending abruptly. His neighbor chuckled: “Looks like they skipped wiring the other side.” It reminded Sam of a news story he once read about how some assemblies shipped without optional features activated, saving initial assembly cost and letting distributors enable them later if customers displayed demand.
Possible Wiring Fixes and Technical Advice
Here’s how to resolve a missing two-speed function:- Confirm factory fit: Some EC35s never had the two-speed option fitted—check original build sheets or a parts catalog to see if the control panel switch was wired to a speed control valve.
- Trace the plug: If a plug exists under the panel with only one wire, it may be a factory-provisioned connection point intended to facilitate later installation.
- Install missing wiring: Run a proper gauge wire from the plug location into the valve block where the two-speed hydraulic solenoid lives. Add appropriate fuse or relay protection.
- Test hydraulic pressure: Ensure hydraulic fluid is clean and set to spec; contaminated oil can hinder diverter valve operation.
- Inspect relief or control valve: A stuck or missing valve can block the high-speed circuit—clean, rebuild, or replace as needed.
- Source parts: Owners have reported difficulty obtaining cylinder-specific seal kits when buying through New Holland—they’re often bundled in expensive kits with irrelevant parts. Shop local hydraulic rebuilders for better value on seals and components.
Suggestions and Practical Recommendations- Safety first: De-energize the electrical system before working under the dash; follow standard maintenance rules as laid out in repair manuals.
- Track tension check: Before testing speeds, ensure tracks are adjusted correctly—1.0 to 1.38 in sag between roller and track is ideal.
- Spend wisely: If two-speed isn’t essential, consider leaving it dormant—but if desired, install components using sourced parts rather than costly OEM kits.
- Document the fix: Label added wiring and note configuration changes in a service log for future maintenance.
Closing Thoughts
In essence, the “hare” lever in a New Holland EC35 may occasionally be dead silence due to a missing circuit or dormant hydraulic circuit. But with careful diagnosis, understanding of the machine’s heritage as a Terex-derived unit, and hands-on wiring and valve work, that bolt-on function can spring to life. For farmers, contractors, or equipment renovators, reviving two-speed travel can transform an undercarriage into a more efficient, versatile machine—turning a curious quirk into practical advantage.
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Building a Custom Grapple for Skid Steer and Loader Applications |
Posted by: MikePhua - 09-02-2025, 01:45 PM - Forum: Equipment Parts , Attachments & Tools
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The Role of Grapples in Material Handling
Grapples are hydraulic attachments designed to grip, lift, and manipulate irregular or bulky materials such as logs, brush, scrap metal, and demolition debris. Unlike standard buckets, grapples offer clamping force and multi-directional control, making them indispensable in forestry, land clearing, and recycling operations. Their versatility has led to widespread adoption across skid steers, compact track loaders, and excavators.
Commercial grapples come in various configurations—root grapples, log grapples, rock grapples—but custom builds allow operators to tailor the design to specific tasks, machine dimensions, and hydraulic capabilities. A well-built grapple can dramatically improve productivity and reduce manual labor, especially in environments where material sorting or selective grabbing is required.
Terminology Annotation - Tines: The curved arms or fingers of the grapple that engage with the material.
- Cylinder Mounts: Brackets that hold the hydraulic cylinders responsible for opening and closing the grapple.
- Pivot Pins: Hardened steel shafts that allow the grapple arms to rotate under hydraulic force.
- Quick Attach Plate: The standardized mounting interface that connects the grapple to the host machine.
Design Considerations and Fabrication Strategy
A successful grapple build begins with understanding the host machine’s lift capacity, hydraulic flow rate, and intended use case. For example, a skid steer with a 2,000 lb rated operating capacity and 15 GPM hydraulic flow can support a mid-sized root grapple with dual cylinders and reinforced tines.
Key design parameters include:- Width: Typically ranges from 60 to 84 inches depending on machine size
- Tine spacing: 6 to 8 inches for brush, tighter for rock or scrap
- Cylinder size: 2.5 to 3 inches diameter with 8 to 10 inches stroke
- Steel thickness: ⅜" to ½" for tines, ¾" for pivot mounts
A fabricator in Idaho built a 72-inch grapple using A36 steel, dual 2.5-inch cylinders, and a universal quick attach plate. The unit weighed approximately 600 lbs and was used to clear slash piles and load firewood. After 200 hours of use, only minor wear was observed on the pivot bushings.
Hydraulic Integration and Control Options
Hydraulic grapples require auxiliary ports and control valves to operate. Most skid steers come equipped with a third-function valve or electric-over-hydraulic switch to activate the grapple. Hoses should be routed with protective sleeves and secured away from pinch points.
Best practices include:- Using flat-face couplers to reduce contamination
- Installing a pressure relief valve to protect cylinders
- Adding a flow restrictor if the grapple moves too quickly
- Testing cylinder synchronization to ensure even clamping
In one case, a grapple built for a compact loader had mismatched cylinder lengths, causing uneven closure and material slippage. The issue was resolved by replacing one cylinder and adjusting the linkage geometry.
Welding Techniques and Structural Reinforcement
Welding is critical to grapple durability. MIG welding with ER70S-6 wire is commonly used for mild steel, while TIG may be employed for precision components. Stress points such as cylinder mounts and tine bases should be gusseted and welded in multiple passes.
Recommended reinforcement strategies:- Triangular gussets at pivot mounts
- Crossbars between tines for lateral rigidity
- Wear strips on the bottom edges
- Bolt-on cutting edges for replaceability
A builder in British Columbia added bolt-on Hardox wear plates to his grapple after noticing abrasion from granite boulders. The upgrade extended the lifespan of the tines by over 300 hours.
Field Testing and Operational Feedback
After fabrication, grapples should be tested under load. This includes:- Lifting logs or brush piles to full extension
- Checking for cylinder leaks or binding
- Verifying quick attach engagement
- Observing tine flex under pressure
Operators often report that custom grapples outperform commercial units in niche tasks. For example, a grapple built with extended lower tines was able to scoop loose hay without spilling, outperforming a standard root grapple in agricultural settings.
Safety and Maintenance Protocols
Grapples must be inspected regularly to prevent failure:- Grease pivot pins every 10 hours
- Check hydraulic hoses for abrasion
- Inspect welds for cracks or fatigue
- Replace bushings and wear strips as needed
Safety tips include:- Never lift loads over personnel
- Avoid side-loading the grapple arms
- Use a spotter when handling long or unstable material
- Keep hands clear during attachment and detachment
In 2022, a forestry crew in Oregon reported a near-miss when a grapple tine failed due to a cracked weld. The incident led to a company-wide inspection protocol and adoption of dye penetrant testing for critical welds.
Conclusion
Building a custom grapple offers unmatched flexibility and performance for operators willing to invest in design and fabrication. By understanding hydraulic requirements, structural loads, and material behavior, a well-built grapple can become a trusted tool across seasons and job types. Whether clearing land, sorting scrap, or feeding a chipper, the right grapple turns a machine into a multi-purpose workhorse. In fabrication, precision and foresight are the true force multipliers.
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