Replacing Hydraulic Hoses in the Telescoping Boom of a JLG 450A

[MikePhua]

The JLG 450A and Its Role in Mid-Range Aerial Work
The JLG 450A articulating boom lift is a mid-sized aerial platform designed for construction, maintenance, and industrial applications requiring elevated access with horizontal outreach. Introduced in the early 2000s, the 450A features a working height of approximately 51 feet and a horizontal reach of 25 feet, making it ideal for tasks like façade repair, lighting installation, and steel erection.
JLG Industries, founded in 1969 and now part of Oshkosh Corporation, has long been a leader in access equipment. The 450A series became popular due to its compact footprint, diesel or electric power options, and robust hydraulic articulation. However, like all boom lifts, the hydraulic hoses that run through the telescoping sections are subject to wear, abrasion, and eventual replacement.
Challenges of Hose Replacement in Telescoping Booms
Replacing hydraulic hoses within the telescoping boom of the 450A is a labor-intensive task due to the confined routing, multiple bends, and hidden clamps. The hoses are bundled and routed through a push tube and a hose track (often referred to as a “catrac”), which guides and protects them during boom extension and retraction.
Terminology annotation:

• Push Tube: A structural sleeve inside the boom that houses and guides hydraulic hoses
  
• Catrac: A hose carrier system that maintains organized movement of hoses during boom articulation
  
• Ferrule: A metal sleeve crimped onto the end of a hydraulic hose to secure fittings
  
• Union: A connector used to join two hose segments
  

Operators often encounter resistance when pulling new hoses through the boom, especially if old clamps, zip ties, or nylon sleeves remain in place. Sharp bends and friction points can cause hoses to snag, stretch, or tear during installation.
Recommended Procedure for Hose Installation
To successfully replace the hoses, the boom must be fully stowed—meaning all sections retracted and lowered. This reduces tension and allows better access to internal routing. The following steps are recommended:

• Remove all clamps and zip ties along the push tube and catrac
  
• Inspect under tin guards and at boom joints for hidden fasteners
  
• Tape over ferrules and unions to prevent snagging on internal edges
  
• Cut off nylon sleeves at knuckle joints to reduce bulk
  
• Use a rope or chain to pull hoses through in short sections
  
• Apply lubricant such as GoJo soap or Windex to reduce friction
  

In one case, a technician used a small chain wrapped around the old hoses and pulled with a backhoe. While effective initially, the hoses began to stretch—prompting a switch to manual pulling with a helper pushing from the opposite end. This two-person method proved more controlled and reduced the risk of damage.
Field Tips and Lessons Learned
Experienced mechanics recommend:

• Pulling hoses section by section rather than all at once
  
• Using sample-built hoses to avoid delays from OEM sourcing
  
• Labeling each hose before removal to ensure correct reconnection
  
• Avoiding excessive force that could damage internal boom components
  

One operator shared that after six hours of effort, he succeeded by taping the hose ends thoroughly and removing unnecessary sleeves. The hoses then slid through with minimal resistance.
Sensor Calibration and Post-Repair Diagnostics
After hose replacement, operators may encounter unrelated issues such as tilt alarms or idle control malfunctions. These are often caused by sensor misalignment or electronic faults triggered during disassembly.
Solutions include:

• Recalibrating the tilt sensor using a JLG analyzer
  
• Inspecting wiring harnesses for dislodged connectors
  
• Resetting control logic via onboard diagnostics or dealer software
  

In some cases, persistent tilt alarms were resolved by disconnecting the sensor entirely—though this is not recommended for machines operating under OSHA or ANSI compliance.
Preventative Measures and Long-Term Maintenance
To extend hose life and simplify future replacements:

• Inspect hose bundles quarterly for abrasion or leaks
  
• Replace worn clamps and zip ties with smooth-edge fasteners
  
• Apply protective sleeves only where necessary to avoid bulk
  
• Keep a record of hose lengths, fittings, and routing diagrams
  

JLG recommends using factory-approved hoses and fittings, but in practice, many technicians rely on hydraulic shops to fabricate replacements based on samples. This approach reduces downtime and allows customization for improved durability.
Conclusion
Replacing hydraulic hoses in the telescoping boom of a JLG 450A is a demanding but manageable task with the right preparation and technique. By stowing the boom, removing all clamps, and using controlled pulling methods with lubrication, operators can navigate the complex internal routing without damaging components. With proper labeling, sensor recalibration, and preventative maintenance, the 450A can return to service safely and reliably—ready to lift, reach, and perform in the field once again.