Front Window Replacement for Hitachi 135US Grey Market Excavators

[MikePhua]

The Hitachi 135US and Its Grey Market Variants
The Hitachi 135US is a compact radius excavator designed for urban and confined job sites. Originally developed for the Japanese domestic market, the 135US features a short tail swing, advanced hydraulic controls, and a fuel-efficient Isuzu engine. Hitachi Construction Machinery, founded in 1970, has long been a leader in excavator innovation, and the 135US series reflects its commitment to precision and operator comfort.
However, many 135US units found in North America are grey market machines—imported directly from Japan without official distribution channels. These machines often differ in cab layout, electrical systems, and part numbers, making sourcing replacement components more complex. The front window, in particular, is a common casualty of jobsite wear, and finding a compatible replacement can be challenging.
Understanding the Cab Glass Configuration
The front window of the 135US is typically a two-piece design:

• Upper Sliding Glass: Mounted on rollers or tracks, allowing it to slide upward into the cab ceiling.
  
• Lower Fixed Glass: Seated in a rubber gasket, providing visibility to the blade or trench.
  

Grey market variants may have different dimensions, mounting hardware, or even glass curvature compared to North American models. Some units use metric-sized glass panels or non-standard seals, which are not listed in official Hitachi parts catalogs distributed in the U.S.
Terminology Clarification

• Grey Market Machine: Equipment imported outside of the manufacturer’s authorized distribution network, often lacking local support or documentation.
  
• Cab Glazing: The glass components of an operator cab, including windshields, side windows, and skylights.
  
• Sliding Sash: A movable window panel that operates on a track or roller system.
  

Sourcing Replacement Glass
When OEM dealers like Pape Machinery are unable to supply the correct window, alternative strategies include:

• Measuring the Existing Frame: Remove the broken glass and measure the opening precisely, including radius corners and gasket depth.
  
• Contacting Glass Fabricators: Many auto glass shops or heavy equipment glaziers can cut laminated safety glass to custom dimensions.
  
• Searching Japanese Part Numbers: Use the machine’s serial number to locate Japanese diagrams and cross-reference part numbers.
  
• Checking Salvage Yards: Equipment dismantlers may have compatible cabs or glass panels from similar models.
  

In one case, a contractor in Oregon sourced a replacement window from a marine glass supplier, using laminated safety glass cut to 6 mm thickness with polished edges. The panel was installed using a universal rubber gasket and performed flawlessly under field conditions.
Installation Tips and Considerations

• Use laminated safety glass, not tempered, to prevent shattering on impact.
  
• Apply urethane sealant or rubber gaskets to prevent leaks and vibration.
  
• Ensure the sliding track is clean and lubricated before installing the upper sash.
  
• If the original mounting hardware is missing, fabricate brackets using stainless steel or aluminum for corrosion resistance.
  

A Story from the Field
In British Columbia, a forestry operator cracked the front window of his grey market 135US while clearing brush. The local dealer couldn’t identify the part, and shipping from Japan was cost-prohibitive. Instead, he partnered with a local glass shop, which templated the opening and cut a new panel within 48 hours. The total cost was under $300, and the machine was back in service by the weekend.
Conclusion
Replacing the front window on a Hitachi 135US grey market excavator requires creativity and precision. While OEM parts may be unavailable or mismatched, custom-cut glass and local fabrication offer practical solutions. By understanding the cab configuration and leveraging regional resources, operators can restore visibility and safety without extended downtime. The key lies in accurate measurement, material selection, and a willingness to adapt beyond the parts catalog.