Restoring Hydraulic Function on a New Holland L325 with Tandem Cessna Pumps

[MikePhua]

The New Holland L325 skid steer uses tandem Cessna hydraulic pumps, and when internal spline failure occurs in the rotating group, replacement parts can be sourced from compatible Eaton or Vickers units. Rebuilding is possible if scoring is minimal and the squash plate can be resurfaced.
New Holland L325 background and pump configuration
The New Holland L325 was introduced in the late 1970s as one of the early compact skid steer loaders designed for general-purpose construction, agriculture, and landscaping. It featured:

• A gasoline or diesel engine depending on configuration
  
• Tandem hydraulic pumps manufactured by Cessna (later acquired by Eaton)
  
• Mechanical linkage for lift and tilt control
  
• Open-center hydraulic system with fixed displacement
  

Cessna hydraulic pumps were widely used in compact equipment during the 1970s and 1980s. Their modular design allowed for tandem configurations, where two pumps are mounted in series to supply separate circuits—typically lift and tilt.
Failure symptoms and rotating group damage
In one case, the rotating group in one of the tandem pumps failed due to spline wear and slipper scoring. Symptoms included:

• Loss of hydraulic pressure in one circuit
  
• Metallic noise during operation
  
• Reduced lift or tilt response
  
• Visible spline stripping on disassembly
  

The rotating group includes the cylinder block, pistons, slippers, and retaining plate. When splines strip, the pump loses rotational drive, and fluid displacement ceases. Scored slippers can damage the squash plate, which controls piston stroke.
Pump identification and part sourcing
Two sets of stamped numbers were found on the pump housing:

• 70142DAK 8M 08 LH
  
• 78112RAU 8A 08 ER
  

These codes suggest either a factory rebuild or reconfiguration. Cessna pumps were later absorbed into Eaton’s product line, and many internal parts cross-reference to Eaton or Vickers series pumps.
To source parts:

• Identify pump series using stamped codes and housing dimensions
  
• Search Eaton-Vickers catalogs for matching rotating groups
  
• Compare slipper diameter, piston count, and spline configuration
  
• Contact hydraulic rebuilders or surplus dealers for core pumps
  

Some Case skid steers (e.g., 1830) used similar pumps, and their internals may be interchangeable. However, linkage differences—such as keyway vs. pin on the squash plate arm—must be accounted for.
Repair strategy and machining options
If the squash plate is only lightly scored:

• Machine the surface flat using precision grinding
  
• Install a shim to restore piston stroke geometry
  
• Replace the rotating group with matched components
  
• Clean all passages and inspect for cross-contamination
  

If both pumps show spline wear, it’s advisable to replace both rotating groups to prevent imbalance or future failure.
Can motor parts be used in pumps
Hydraulic motors and pumps often share similar rotating group designs, but tolerances and flow characteristics differ. Using motor parts in a pump is risky unless verified by part number and application. Motors may have different slipper profiles or piston lengths.
Recommendations and sourcing tips

• Use hydraulic rebuilders familiar with legacy Cessna/Eaton units
  
• Avoid mixing parts from different series unless verified
  
• Document all part numbers and dimensions during teardown
  
• Consider upgrading to modern Eaton pumps if rebuild parts are unavailable
  
• Check salvage yards for donor units from Case, Ford, or early New Holland machines
  

One technician in Ohio rebuilt his L325 pump using parts from a retired Case 1830. After machining the squash plate and replacing the rotating group, the loader returned to full function and has operated reliably for over a year.
Conclusion
The New Holland L325’s tandem Cessna pumps can be rebuilt using compatible Eaton or Vickers parts, provided the squash plate is repairable and the rotating group is matched correctly. With careful sourcing and machining, even older hydraulic systems can be restored to reliable service. Cross-referencing pump codes and understanding internal geometry are key to successful repair.