Galion T-500 Cylinder Leak and Vintage Hydraulic Repair Strategy

[MikePhua]

The Galion T-500 and Its Place in Grader History
The Galion T-500 motor grader is a product of the Galion Iron Works legacy, a company that helped shape the American road-building industry throughout the 20th century. Known for its mechanical simplicity and robust steel construction, the T-500 was designed for municipal and rural grading tasks. With a rigid frame, direct mechanical controls, and hydraulic lift cylinders for the moldboard, it offered reliable performance in an era before electronic integration.
Galion Iron Works, founded in Ohio in the early 1900s, was eventually absorbed into Komatsu America. The T-500, likely produced in the late 1960s, represents a transitional period in grader design—where hydraulic systems began replacing cable and gear-driven mechanisms but retained serviceable components like packing glands and manually adjustable seals.
Identifying the Source of Hydraulic Fluid Leakage
A common issue with older graders like the T-500 involves hydraulic fluid leaking from the top of the moldboard lift cylinder. In this case, the leak was external, occurring around the ram where it enters the cylinder barrel. Unlike modern cylinders that use integrated lip seals or cartridge-style gland assemblies, the T-500 relies on a packing gland system—typically composed of V-packings compressed by a gland nut or cap.
Terminology:

• Packing gland: A mechanical assembly that compresses sealing rings around a moving shaft to prevent fluid leakage.
  
• V-packing: A stack of chevron-shaped rubber or fabric seals that expand under pressure to form a tight seal.
  
• Rod wiper: A seal at the cylinder entrance that removes debris from the rod before it enters the gland.
  
• Gland bolts: Fasteners that draw the gland cap down to compress the packing.
  

In this case, the brass gland cap had bottomed out, indicating that the packing could no longer be compressed to seal effectively. This is a clear sign that the V-packings have worn out and need replacement.
Disassembly and Inspection of the Cylinder Assembly
To repair the leak, the cylinder must be partially disassembled. Fortunately, the design allows for field service without removing the entire barrel from the machine.
Recommended steps:

• Disconnect the cylinder eye from the moldboard linkage
  
• Remove the gland bolts and slide the gland cap up the rod
  
• Use a pipe wrench or chain wrench to unscrew the large end cap from the barrel
  
• Withdraw the rod and plunger assembly carefully
  
• Secure the rod in a bench vise and remove the retaining nut
  
• Disassemble the plunger and inspect internal seals and wear surfaces
  
• Clean all components thoroughly before reassembly
  

Tools required:

• ¾" impact wrench and socket set
  
• Pipe wrench or chain wrench rated for large diameters
  
• Bench vise with soft jaws or wood blocks
  
• Seal pick or corkscrew tool for removing old packing
  
• Torque wrench for gland bolts (typically 35 ft-lbs)
  

One technician in Minnesota shared that he uses a homemade wooden cradle to stabilize the rod during seal installation, preventing damage to the new packing and speeding up the process.
Sourcing Replacement Seals and Packing Materials
Finding seals for vintage equipment can be challenging. While Komatsu may still stock parts for legacy Galion machines, many operators turn to hydraulic shops or industrial suppliers for custom solutions.
Options include:

• OEM seal kits from Komatsu or legacy Galion dealers
  
• Custom-cut V-packings from hydraulic rebuild shops
  
• Rope packing as a substitute, cut at 45° and staggered
  
• Double-faced wiper seals for external debris protection
  

Tips:

• Bring the old packing and gland dimensions to the supplier for matching
  
• Order two sets to account for installation errors or future failures
  
• Verify material compatibility with hydraulic fluid type (e.g., nitrile vs Viton)
  
• Avoid over-tightening gland bolts—wire tie or torque to spec
  

One operator in Pennsylvania noted that his local NAPA store had a hydraulics specialist who could match seals by measurement, saving him days of downtime.
Vintage Cylinder Behavior and Preventive Maintenance
Older cylinders like those on the T-500 often use adjustable packing systems that can be tightened periodically to maintain sealing pressure. However, once the packing compresses fully, replacement is the only solution.
Preventive strategies:

• Inspect gland bolt torque monthly
  
• Monitor for external leaks and fluid loss
  
• Clean rod wipers regularly to prevent grit intrusion
  
• Replace fluid annually to reduce seal degradation
  
• Keep a log of cylinder service intervals and seal types
  

One grader operator in Missouri added a small inspection mirror to his daily walkaround kit, allowing him to check for leaks at the cylinder tops without climbing onto the machine.
Conclusion
Repairing a leaking moldboard lift cylinder on a Galion T-500 is a straightforward but nuanced task. With a clear understanding of packing gland mechanics, proper disassembly technique, and access to compatible seals, even a 50-year-old grader can be restored to reliable service. In the world of vintage iron, patience and precision are the keys to keeping hydraulic systems sealed and functional—one V-packing at a time.