Removing and Servicing the Tilt Cylinder on a CAT 953C Track Loader

[MikePhua]

The CAT 953C and Its Loader Geometry
The CAT 953C track loader, introduced in the late 1990s, was part of Caterpillar’s evolution of mid-sized crawler loaders designed for versatility in construction, demolition, and land clearing. With an operating weight around 33,000 lbs and a bucket capacity of 2.5–3.0 cubic yards, the 953C featured a Z-bar linkage system for breakout force and a tilt cylinder mounted centrally between the bucket and the loader frame.
The tilt cylinder plays a critical role in controlling bucket angle during digging, grading, and dumping. Over time, seals wear, rods pit, and hydraulic leaks develop—necessitating removal and rebuild.
Accessing the Tilt Cylinder Safely
Before removing the tilt cylinder, the machine must be positioned on level ground with the bucket fully lowered. Hydraulic pressure should be relieved by placing the loader in float mode and cycling the controls. The cylinder weighs approximately 300 lbs, so lifting equipment or a second technician is recommended.
Key safety steps:

• Lower bucket to ground and shut off engine
  
• Engage hydraulic float and cycle tilt control
  
• Disconnect battery to prevent accidental activation
  
• Use cribbing or blocks to support the cylinder during removal
  
• Wear eye protection when loosening hydraulic lines
  

Pin Removal and Hose Clearance
The tilt cylinder is secured by two pins—one at the rod end near the bucket, and one at the head end near the cab. The lower pin is typically straightforward to remove, but the upper pin may be obstructed by hydraulic hoses or the tank cover.
To gain clearance:

• Remove the hydraulic tank cover if necessary
  
• Loosen or disconnect the hydraulic hoses at the cylinder head
  
• Rotate the pin slightly to maneuver around hose fittings
  
• Watch for locking tabs or flags that are part of the pin assembly
  

Some machines may have a bucket positioner or kick-out mechanism mounted to the cylinder. These components must be unbolted prior to cylinder removal. Keep track of spacers and washers during disassembly.
Cylinder Disassembly and Seal Replacement
Once removed, the cylinder can be serviced on a bench or upright stand. The rod assembly is extracted by removing the head and loosening the opposite hose to allow fluid drainage. Care must be taken to avoid damaging the chrome rod or cutting new seals during reinstallation.
Disassembly tips:

• Loosen head bolts evenly to prevent warping
  
• Drain residual oil into a clean container
  
• Support the rod to prevent swinging or impact
  
• Use piston ring compressors to size new seals
  
• Lubricate seals thoroughly before reassembly
  
• Insert rod squarely to avoid pinching or tearing
  

One technician recommended standing the barrel vertically to allow the rod to be pulled straight up and lowered back in with minimal risk. Another noted that reinserting the rod may require gentle tapping with a mallet—on the rod end only, never the piston.
Common Pitfalls and Field Advice
Operators have reported several challenges during tilt cylinder service:

• Pins seized due to rust or lack of grease
  
• Hydraulic lines under residual pressure causing spray
  
• Rods scratched by contact with Z-bar linkage during removal
  
• Seals damaged during insertion due to misalignment
  
• Cylinder head threads cross-threaded during reassembly
  

To avoid these issues:

• Apply penetrating oil to pins before removal
  
• Loosen hydraulic fittings slowly and allow pressure to bleed
  
• Use protective sleeves or guides when inserting rods
  
• Confirm alignment visually and by feel before torquing bolts
  
• Replace any worn or damaged hardware during service
  

When to Call in Professional Help
While many technicians can handle cylinder removal and seal replacement, not all have the tools or strength to manage a 300 lb hydraulic assembly. In one case, an operator opted to call the local CAT dealer after realizing he lacked the equipment to safely remove the rod nut and reinstall the cylinder. The dealer completed the job and had the machine back in service within a day.
Signs that professional service may be needed:

• Lack of lifting equipment or secure rigging
  
• Inability to torque large nuts without damaging threads
  
• Uncertainty about seal sizing or piston condition
  
• Risk of damaging chrome rod or cylinder bore
  

Conclusion
Servicing the tilt cylinder on a CAT 953C is a manageable task with the right preparation, tools, and attention to detail. From pin removal to seal installation, each step requires care to avoid damage and ensure long-term performance. Whether done in-house or by a dealer, restoring hydraulic integrity is essential for maintaining the loader’s precision and power. In the world of heavy iron, even a single cylinder can make or break the job.