BobCat S70 – CYLINDER (LIFT) Disassembly And Assembly

Use the following tools to disassemble and assemble the cylinder:
MEL 1074 – O-ring Seal Hook
MEL 1396 – Seal Installtion Tool
MEL 1033 – Rod Seal Installation Tool
Piston Ring Compressor
Spanner Wrench
Hold the hydraulic cylinder over a drain pan and move the rod in and out slowly to remove the fluid from the cylinder.

Put the base end of the cylinder in a vise.

Use a spanner wrench to loosen the head [Figure 20-20­11].

Remove the head and the rod assembly from the cylinder [Figure 20-20-12].
Put the rod end in a vise.
Remove the nut (Item 1), piston (Item 2), spacer (Item 3) and head (Item 4) [Figure 20-20-12].
Assembly: Tighten the nut (Item 1) [Figure 20-20-12] to R300 ft.-lb. (407 N*m) torque.

Remove the seal (Item 1) and O-ring (Item 2) from the piston (Item 3) [Figure 20-20-13].

Remove the thick O-ring (Item 1) and the back-up washer (Item 2) from the groove in the head. Remove the thin O-ring (Item 3) [Figure 20-20-14].

Remove the wiper seal (Item 1), and rod seal (Item 2) [Figure 20-20-15].
Remove the O-ring (Item 3) [Figure 20-20-15] from the rod seal.
Wash the cylinder parts in solvent and air dry them.
Inspect the cylinder for nicks, scratches or other damage.
Replace any damaged parts.
Always install new O-rings and seals during assembly.
Lubricate all O-rings and seals with hydraulic oil during installation.

Install a new seal on the tool and slowly stretch it until it fits the piston (Item 1) [Figure 20-20-16].
Allow the seal the stretch for 30 seconds before installing it on the piston.
Use a ring compressor to compress the seal to the correct size. Leave the piston in the compressor for about three minutes.

Install the rod seal on the rod seal tool [Figure 20-20-17].
NOTE: During installation the O-ring side of the seal must be toward the inside of the cylinder.
Rotate the handles to collapse the rod seal.

Install the rod seal in the head [Figure 20-20-18].
Install the wiper seal with the wiper toward the outside of the head.
Assemble the cylinder(s) in the reverse order.

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