Safe Reinflation Practices for 23.5-25 O-Ring Earthmover Tires

[MikePhua]

The Role of O-Ring Seals in Multi-Piece Rims
Earthmover tires like the 23.5-25 are commonly mounted on multi-piece rims, which include a lock ring, bead seat band, and an O-ring seal. The O-ring is a critical component that ensures airtight sealing between the rim components and the tire bead. It sits in a machined groove on the bead seat band and compresses during assembly to prevent air leakage under high pressure.
These tires are typically used on loaders, scrapers, and articulated dump trucks. The 23.5-25 size is standard for mid-sized wheel loaders and offers a balance of flotation, traction, and load-bearing capacity. When reinflating after dismounting or servicing, the O-ring must be correctly seated to avoid catastrophic failure.
Risks Associated with Improper O-Ring Seating
Improper installation of the O-ring can lead to:

• Sudden air loss during inflation
  
• Explosive separation of rim components
  
• Tire bead dislodgement
  
• Injury or death from flying debris
  

The danger is highest during initial inflation, when pressure builds rapidly and the lock ring may not be fully engaged. If the O-ring is pinched, twisted, or misaligned, it can allow air to escape into the rim cavity, lifting the bead seat band and ejecting the lock ring violently.
One technician in Alberta recalled a loader tire exploding during inflation due to a misseated O-ring. The lock ring struck a nearby wall with enough force to dent steel. After that incident, the shop implemented a mandatory cage policy and retrained all staff on multi-piece rim procedures.
Inspection and Preparation Before Inflation
Before reinflating a 23.5-25 tire:

• Inspect the O-ring for cracks, flat spots, or hardening
  
• Clean the groove and apply rubber lubricant or tire soap
  
• Verify that the bead seat band and lock ring are free of rust and burrs
  
• Confirm that the tire bead is evenly seated on both sides
  
• Use a certified inflation cage or remote inflation system
  

The O-ring should sit flush in its groove without bulging or twisting. If it appears stretched or dry, replace it. Never reuse an O-ring that has been exposed to heat, petroleum products, or excessive wear.
Inflation Procedure and Safety Protocols
Recommended inflation steps:

• Place the tire and rim assembly in a certified cage rated for earthmover tires
  
• Attach a remote inflation valve with a pressure gauge
  
• Inflate slowly to 5 psi and inspect for movement or air leaks
  
• Continue inflation in 5 psi increments, checking lock ring engagement
  
• Stop immediately if any component shifts or hisses
  
• Inflate to operating pressure (typically 45–65 psi) only after full seating
  

Always stand clear of the trajectory zone—an imaginary path where the lock ring could eject. Use barriers or shields if a cage is not available, though this is not a substitute for proper equipment.
Common Mistakes and Field Corrections
Frequent errors include:

• Installing the O-ring dry, leading to friction and pinching
  
• Using petroleum-based lubricants that degrade rubber
  
• Failing to inspect the groove for debris or corrosion
  
• Inflating too quickly without staged pressure checks
  
• Assuming visual seating is sufficient without tactile confirmation
  

Solutions:

• Use vegetable-based tire soap or glycerin for lubrication
  
• Replace O-rings every time the tire is dismounted
  
• Train technicians to feel for proper seating with gloved hands
  
• Implement a checklist for multi-piece rim assembly
  
• Require cage use for all tires over 20 inches rim diameter
  

A contractor in Nevada switched to color-coded O-rings to help identify wear and age. His team reduced inflation incidents by 90% after adopting a barcode-based inspection log.
Regulatory Standards and Industry Guidelines
OSHA and MSHA regulations mandate specific procedures for servicing multi-piece rims. Key requirements include:

• Use of restraining devices during inflation
  
• Training for all personnel handling rim assemblies
  
• Written procedures for inspection and repair
  
• Lockout of inflation equipment during servicing
  

Industry groups like TIA (Tire Industry Association) offer certification programs and manuals for earthmover tire safety. These resources emphasize the importance of O-ring integrity and proper inflation technique.
Conclusion
Reinflating a 23.5-25 tire with an O-ring seal demands precision, patience, and respect for the forces involved. The O-ring may seem like a minor component, but its role in sealing and safety is critical. With proper inspection, lubrication, and inflation protocols, technicians can avoid dangerous failures and keep machines rolling safely. In the world of heavy equipment, attention to detail at the rim can mean the difference between uptime and tragedy.