Replacement Grease Line for Yanmar ViO55 Excavators

[MikePhua]

Overview of the Grease Line Scenario
A key maintenance task on the Yanmar ViO55 excavator is ensuring reliable lubrication to the swivel or pinion bearings. An owner faced with worn or unavailable OEM grease lines wondered if there’s a lower-cost, readily available alternative. The original grease line features a plastic tube with a flared end and a standard 1/8-inch NPT threaded fitting—raising the question: what generic product could substitute effectively?
Practical Solutions Offered by Owners
Different approaches were suggested by experienced users based on durability, pressure resistance, and ease of replacement:

• Compressed Air Tubing: One user recommended using 1/4-inch push-to-connect air lines and fittings—commonly used for pneumatic grease ring assemblies. These are inexpensive and quick to swap when a line fails, though they may burst under grease pressure.
  
• Grease Gun Flexible Hoses: These hoses, sold wherever grease cartridges are available, are flexible, robust, and designed to withstand high pressure. They could serve as dependable, field-ready replacements.
  
• Nylaflow Nylon Tubing: A high-quality synthetic alternative, Nylaflow nylon line is rated for hydraulic oil and greasing applications. It’s chemically resistant and flexible, available in many diameters—ideal for a permanent solution.
  

Yanmar Model Context and Company Overview

• Compact Excavator Role
  The ViO55 is part of Yanmar’s ViO zero-tail swing excavator line, valued for maneuverability in tight spaces. The original ViO debuted in 1993 and by 2013 had evolved into the ViO45/55-6 generation, offering improved fuel economy, easier maintenance, and comfort upgrades.
  
• Holdings at a Glance
  Yanmar Holdings Co., Ltd., founded in 1912, is a Japanese manufacturer of diesel engines and compact machinery. Over the years, it has branched into construction, agriculture, marine, and remote monitoring technologies. Its ViO excavator series highlights Yanmar’s steady innovation and global presence.
  

Suggested Replacement Options at a Glance
Option
DescriptionPush-to-connect air line (¼")
Easily replaceable and very inexpensive, though may burst if grease passage is blocked.
Grease-gun flexible hose
Durable, high-pressure rated, common at lubrication tool suppliers.
Nylaflow nylon line
Flexible, oil-immersion resistant, available in many sizes, suitable for lasting repairs.
Recommendations & Maintenance Advice

• Match thread type: Ensure any replacement has a 1/8-inch NPT fitting to fit the grease nipple port securely.
  
• Prioritize flexibility: The grease line should bend without kinking—especially around tight pivots like slewing bearings.
  
• Confirm pressure rating: Grease systems can operate at several hundred psi, so choose hoses explicitly rated for that pressure.
  
• Have quick swaps handy: Using air line tubing lets you carry a spare and avoid prolonged downtime if a grease path plugs up.
  
• Consider durability for long term: If longevity is more critical, opt for a certified grease hose or Nylaflow tubing for dependable service.
  

Conclusion
Replacing the grease line on the Yanmar ViO55 needn’t be costly or complex. Flexible hoses designed for grease guns or robust nylon hydraulic lines offer reliable, readily available solutions. Quick-connect air tubing makes a smart emergency backup despite its lower burst resistance. Choosing the right material—balanced with pressure capacity and flexibility—keeps your excavator lubricated and working smoothly, without a premium parts price tag.