CAT 307 Stabilizer Cylinder Details

[MikePhua]

Caterpillar's robust mini-excavator lineup, particularly models like the 307 and 307A, have long featured dependable stabilizer cylinders designed to support balance and control on uneven terrain. Those seeking part and maintenance information for these key hydraulic components will find the following insights both practical and informative.
Cylinder Identification and Specifications
One reliable way to identify the correct stabilizer cylinder for CAT 307 and early 307A models is by part numbers:

• Left-hand stabilizer cylinder: 107-6377
  
• Right-hand stabilizer cylinder: 107-6472
  

These cylinders match a configuration used in early 307A machines with 2PM or 2WM serial prefixes, and they’re also compatible with some 2FL-prefix models.
Key Dimensions

• Bore (barrel internal diameter): 90 mm
  
• Rod diameter (chrome finish): approximately 50 mm
  
• Stroke length: 172 mm
  

These specifications ensure proper fit and hydraulic performance, whether replacing or refurbishing components.
Terminology Note (Glossary)

• Bore: The internal width of the cylinder barrel, determining fluid volume.
  
• Rod diameter: Thickness of the piston rod, critical for structural integrity.
  
• Stroke: Maximum extension distance of the cylinder, defining deployment range.
  

Refurbishment & Seal Kit Options
Owners can choose between full replacement or revitalization of existing cylinders:

• Rod re-chroming is a cost-effective option if the cylinder barrel is intact and precise measurements confirm the correct sizing.
  
• For resealing, several rebuild kits are available, including blade cylinder seal kits for CAT 307 excavators, designed for rods 50 mm in diameter and bore of 90 mm, aligning with stabilizer specs.
  

Practical Recommendations

• Measure before repair: Confirm bore (90 mm), rod diameter (~50 mm), and stroke (172 mm) before ordering replacements or parts.
  
• Evaluate wear first: If the cylinder rod is free from deep scratches and barrel integrity is maintained, re-chroming and new seals can restore performance at reduced cost.
  
• Select correct kits: For CAT 307 stabilizers or blade cylinders, look for seal kits matching the part numbers 107-6377 and 107-6472 with the specified rod/bore dimensions.
  

Stabilizer Cylinder Overview

• Left Stabilizer Cylinder: Part Number 107-6377
  
• Right Stabilizer Cylinder: Part Number 107-6472
  
• Bore Diameter: 90 mm
  
• Rod Diameter: Approx. 50 mm
  
• Stroke Length: 172 mm
  
• Refurbishment Options: Rod re-chroming and new seals
  
• Seal Kit Availability: Blade cylinder kits that match dimensions
  

Closing Thoughts
Understanding the exact specifications and part numbers of CAT 307 stabilizer cylinders empowers users to make informed decisions—whether they’re choosing replacements or undertaking economical refurbishments. Precise measurement and correct component selection are the foundation of long-term reliability and operational confidence in the field.