Replacing Hydraulic Hoses on the Ford 755A Backhoe

[MikePhua]

The Ford 755A and Its Mechanical Legacy
The Ford 755A backhoe loader was introduced in the late 1970s as part of Ford’s industrial equipment lineup, which had already gained traction in North America and Europe for its robust agricultural tractors. The 755A was powered by a Ford diesel engine delivering around 60 horsepower and featured a fully integrated loader-backhoe configuration. Its hydraulic system was designed for simplicity and serviceability, making it a favorite among municipal crews, farmers, and small contractors.
Ford’s industrial division, later absorbed into New Holland, sold tens of thousands of 755-series machines globally. The 755A stood out for its mechanical reliability and straightforward hydraulic architecture, but as these machines aged, hose replacement became a recurring challenge due to tight routing and limited access.
Understanding the Hydraulic Hose Network
The hydraulic system on the 755A includes:

• Lift control valve: Directs fluid to the boom, crowd, and bucket cylinders.
  
• Boom tubing: Internal steel lines that carry fluid from the valve to the cylinders.
  
• Swing post: A rotating structure through which hoses are routed to reach the boom.
  
• Hose clamps: Secure hoses to prevent chafing and maintain alignment.
  
• Quick couplers and fittings: Connect hoses to valves and cylinders.
  

Each hose is part of a matched pair—typically labeled 1 through 4—delivering and returning fluid to the crowd and bucket cylinders. Proper routing is essential to prevent abrasion, kinking, and interference during swing or lift operations.
Accessing the Hose Routing Points
Replacing hoses on the 755A requires strategic disassembly:

• Remove the rear deck plate to expose the lift control valve.
  
• Identify the hose pairs and their routing through the swing post.
  
• Use access holes in the mounting plate to reach internal fittings.
  
• Loosen clamps securing the hoses to the frame and boom.
  

Operators often find that the hoses cross inside the swing post and must be routed in parallel to avoid chafing. If the post is not centered during installation, hose tension can increase, leading to premature wear.
In one case from Oregon, a technician used a crowfoot line wrench to reach a buried fitting inside the swing post. The thin-walled tool allowed access between tightly packed hoses, saving hours of frustration.
Tagging and Documentation for Hose Replacement
To avoid confusion during reassembly, technicians recommend tagging each hose and its corresponding fitting:

• Use numbered wire tags (1, 2, 3, 4) on both ends of each hose.
  
• Photograph the routing before removal using a smartphone.
  
• Transfer tags to new hoses during fabrication.
  
• Record hose lengths and fitting types for future reference.
  

This method was popularized by municipal fleet managers who needed to maintain consistency across multiple machines. In one fleet, tagging reduced hose misrouting incidents by 85%.
Removing Paint and Loosening Stubborn Fittings
Paint buildup and corrosion can make hose removal difficult. A proven solution involves:

• Applying a 50/50 mix of acetone and automatic transmission fluid (ATF) as a penetrating agent.
  
• Using a wire brush to remove paint from bolt heads and fittings.
  
• Allowing the mixture to soak for 15–30 minutes before attempting removal.
  

This homemade penetrant has gained popularity among field mechanics for its effectiveness and low cost. A technician in Montana reported that it outperformed commercial products in freeing seized fittings on a 755A that had sat unused for five years.
Tools and Techniques That Make the Job Easier
Recommended tools for hydraulic hose replacement:

• Crowfoot line wrench (thin-walled)
  
• Breaker bar or flex-handle ratchet
  
• Hose tag kit with wire loops
  
• Snap-ring pliers for cylinder disassembly
  
• Small wire brush for cleaning threads
  
• Bucket or tray for catching hydraulic fluid
  

A mechanic in British Columbia once described the process as “a test of patience more than skill.” He kept a five-gallon bucket labeled “patience” next to the machine—a humorous reminder to slow down and avoid forcing parts.
Sourcing Replacement Hoses and Fittings
Many hydraulic shops can fabricate hoses to match OEM specifications. When ordering:

• Provide hose length from clamp to fitting
  
• Specify thread type (JIC, NPT, ORFS)
  
• Indicate pressure rating (typically 3,000 psi for the 755A)
  
• Request abrasion-resistant outer jackets for swing post routing
  

In Spokane, a shop called House of Hose became known for custom fabrications for Ford industrial machines. Their technicians often replicated hoses using tagged samples and photos, ensuring accurate replacements.
Preventive Measures for Future Reliability
To extend hose life and simplify future replacements:

• Use hose sleeves or spiral wrap in high-abrasion areas
  
• Install additional clamps to reduce movement
  
• Avoid sharp bends near fittings
  
• Replace hoses in matched pairs to maintain flow balance
  
• Flush the hydraulic system after major hose replacement
  

Operators in wet climates often coat fittings with dielectric grease to prevent corrosion. In dry regions, UV-resistant hose jackets are preferred to prevent cracking.
Conclusion
Replacing hydraulic hoses on the Ford 755A is a hands-on task that rewards patience and preparation. With proper tagging, access tools, and routing discipline, even the most buried fittings can be reached and replaced. The 755A’s enduring design means that with fresh hoses and clean connections, it can continue working decades beyond its original service life. Whether digging trenches in rural fields or clearing debris in urban lots, its hydraulic system remains the lifeblood of its performance—and the hoses, its arteries.