D155 Cara overhaul lift cylinder 

Summary

This video details the disassembly process of the hydraulic lift cylinder on a D155-6 machine. The technician demonstrates step-by-step how to carefully remove various components, including pipes, the cylinder head, and the piston, while ensuring safety by using gloves and oil containment. Key steps include inspecting and replacing seals and O-rings, checking for physical damage, and handling components with precision. The process also highlights the importance of maintaining proper pressure alignment with the backup ring and emphasizes thorough inspection for any potential wear or damage before reassembly.

Takeaways

• 😀 Ensure safety during the disassembly process by wearing gloves and preparing an oil catch container.
• 😀 Begin by removing the piping from the lift cylinder and be cautious not to spill oil, as it is hazardous waste.
• 😀 Use a pipe wrench to loosen and remove the cylinder head, and continue to turn until all oil is drained.
• 😀 Once the oil is drained, carefully remove the cylinder and piston components. Handle the parts gently to avoid damage.
• 😀 Inspect the piston and its components for wear or damage, particularly the seals and O-rings, to ensure they can still function properly.
• 😀 Replace damaged O-rings during reassembly, but only replace backup rings if they show signs of damage.
• 😀 Always verify the orientation of the backup ring during reassembly. It must face the pressure side correctly.
• 😀 Be careful when removing the seals and O-rings, especially the black ones, as these are critical for maintaining pressure.
• 😀 Take note of the orientation of all seals and components during disassembly to ensure correct reassembly.
• 😀 Perform a physical inspection of all components, including the piston and valve parts, to ensure they have no significant damage that could impair function.

Q & A

What is the first step in disassembling the lift cylinder?

The first step is to remove the piping attached to the cylinder.

What safety precautions are mentioned during the disassembly process?

It is important to wear gloves for safety and prepare a container to catch any oil to avoid spillage, as the oil is considered waste.

What tool is used to open the head of the cylinder?

A pipe wrench is used to open the head of the cylinder, followed by a hook wrench for easier loosening.

What should be done with the oil during the disassembly process?

The oil should be drained carefully into a container to avoid spillage, as it is considered hazardous waste.

What is the role of the teflon layer in the cylinder disassembly?

The teflon layer, along with the seal inside, is part of the internal components of the cylinder that need to be removed and checked for any damage.

What should be inspected on the piston and valve piston?

The piston and valve piston should be inspected to ensure that they do not have any damage, as any bumps or dents could prevent proper functioning.

How should the O-rings be handled during reassembly?

The O-rings should be replaced with new ones. However, the backup ring may not need replacement unless it shows signs of damage.

What is the correct orientation for the backup ring during reassembly?

The backup ring should be installed so that its pressure side faces opposite to the pressure direction.

What is the process for removing and replacing seals?

The seals, including the O-rings, should be removed carefully, and new seals should be installed, making sure they are in the correct position and orientation.

How are the components of the cylinder protected during disassembly?

The components are handled carefully to avoid damage, with specific attention paid to keeping small components in the right orientation to prevent contamination or damage.