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Restoring the JLG 70G: Challenges of Obsolete Hydraulic Components and Practical Solutions
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Introduction: When Legacy Equipment Meets Modern Demands
The JLG 70G, a rugged telehandler from a previous generation of material handling equipment, remains in use across construction sites and industrial yards due to its durability and lifting capacity. However, as with many older machines, sourcing replacement parts—especially for hydraulic control systems—can become a daunting task. This article explores the challenges of maintaining legacy equipment like the JLG 70G, focusing on the Racine control valve and its obsolete coil components. We’ll also examine practical workarounds, sourcing strategies, and field anecdotes that highlight the ingenuity required to keep these machines operational.
Understanding the Racine Control Valve System
The Racine control valve is a hydraulic directional control unit used to manage fluid flow to various actuators—such as lift cylinders, tilt functions, and steering mechanisms. In the JLG 70G, this valve plays a central role in distributing hydraulic pressure from the pump to the appropriate circuits.
Key components include:
  • Solenoid Coils: Electromagnetic devices that actuate valve spools when energized.
  • Spool Valves: Internal sliding elements that direct fluid flow.
  • Manifold Block: The housing that integrates multiple valve functions.
Over time, solenoid coils can fail due to heat, vibration, or corrosion. Unfortunately, Racine-branded coils for older models are no longer manufactured, leaving operators with limited options.
Challenges of Obsolete Parts
  • Discontinued Manufacturing: Racine was absorbed into larger hydraulic brands, and many legacy parts were phased out.
  • Compatibility Issues: Modern coils may not match the voltage, mounting dimensions, or connector type.
  • Limited Documentation: Technical manuals for older machines are often incomplete or unavailable.
Field Anecdote: Florida Telehandler Repair
An operator in Florida faced a breakdown when the lift function on his JLG 70G stopped responding. Diagnosis revealed a failed coil on the Racine valve. After searching local suppliers and online catalogs, he discovered that the original coil model was discontinued. Rather than scrapping the machine, he pursued a retrofit solution using a compatible coil from a newer hydraulic system—modifying the connector and housing to fit.
Solutions and Workarounds
  1. Cross-Referencing Coil Specs
    • Identify voltage (typically 12V or 24V DC), amperage, and connector type.
    • Match coil dimensions and thread pitch to modern equivalents.
  2. Custom Fabrication
    • Machine adapters or brackets to fit newer coils onto the Racine valve body.
    • Use epoxy or thermal-resistant sealants to secure retrofits.
  3. Salvage Yards and Rebuilders
    • Contact hydraulic rebuild shops that specialize in obsolete systems.
    • Search for donor machines with compatible Racine components.
  4. Electrical Rewiring
  • Modify wiring harnesses to accommodate different coil connectors.
  • Install inline fuses or relays to match current draw.
Recommended Parameters for Coil Replacement
  • Voltage: Match original system (commonly 12V or 24V DC)
  • Coil Resistance: Typically 10–30 ohms depending on model
  • Connector Type: DIN 43650 or Deutsch DT series
  • Mounting Thread: Confirm with calipers; common sizes include 5/8"-18 or M20x1.5
Preventive Maintenance Tips
  • Heat Management: Ensure coils are not exposed to excessive engine heat or hydraulic fluid temperatures.
  • Vibration Dampening: Use rubber mounts or isolators to reduce coil fatigue.
  • Moisture Protection: Seal connectors with dielectric grease and weatherproof boots.
Historical Parallel: The Case of the Clark C500
In the early 2000s, operators of Clark C500 forklifts faced similar issues with obsolete hydraulic coils. A small shop in Ohio began retrofitting newer coils and selling adapter kits, keeping hundreds of machines in service. This grassroots solution became a model for legacy equipment support.
Conclusion: Keeping the JLG 70G Alive
Maintaining older equipment like the JLG 70G requires creativity, persistence, and a willingness to adapt. While OEM support may be limited, the aftermarket and rebuild community offer viable paths forward. By understanding the technical requirements of components like the Racine control valve and exploring retrofit options, operators can extend the life of their machines and avoid costly replacements.
Final Advice
Document every retrofit. Keep records of coil specs, wiring changes, and part sources. This not only helps future repairs but also adds value if the machine is ever sold. In the world of legacy equipment, knowledge is just as valuable as hardware.
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