BobCat S70 – CYLINDER (TILT) Testing

Remove the attachment. Tilt the Bob-Tach fully forward until it rests on the floor. Stop the engine. Raise the seat bar.

Disconnect the hose (Item 1) [Figure 20-21-1] from the base end of the tilt cylinder.
Install a plug in the hose and tighten the plug.
Lower the seat bar, engage the parking brake and start the engine.
Push the bottom (heel) if the tilt pedal until system relief pressure is reached.
There should be no leaks from the base end of the port.
If there is leakage from the open port of the tilt cylinder, remove the cylinder for repairs.

Remove the hoses (Item 1) [Figure 20-21-3] from the tilt cylinder fittings.

Remove the bolt (Item 1) and the retainer (Item 2) [Figure 20-21-4] from the base end of the tilt cylinder.

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.

BobCat S70 – CYLINDER (LIFT) Removal And Installation

Fully lower the lift arms.
Stop the engine. Pull up on the lift arm by-pass control and move the lift pedal to release the hydraulic pressure. Raise the seat bar. Engage the parking brake. Raise the operator cab.

Install a lifting strap around the center of the lift arms crossmember, fasten the strap to a chain hoist and the lift arms slightly as shown [Figure 20-20-4].
Remove the rod end retainer bolt (Item 1) [Figure 20-20­ 4] from the left cylinder.
Installation: Tighten the bolt to 18-20 ft.-lb. (24-27 N*m) torque.
Remove the retainer and the rod end pin [Figure 20-20­ 4].

Lower the left cylinder onto the fender [Figure 20-20-5].

Remove the bolt (Item 1) [Figure 20-20-6] to remove the cover and pivot pin from the right lift cylinder.
Installation: Tighten the bolt to 18-20 ft.-lb. (24-27 N*m) torque.
Remove the cover and pivot pin [Figure 20-20-6].

Lower the right lift cylinder onto the fender [Figure 20-20­7].

Open the rear door.
Remove the bolt (Item 1) [Figure 20-20-8] from the base end pin retainer (left side shown).
Installation: Tighten the bolt to 18-20 ft.-lb. (24-27 N*m) torque.

Use a slide hammer to remove the pivot pin (left side shown) [Figure 20-20-9].

Pull the cylinder forward to remove the hose (Item 1) from the base end and the hose (Item 2) [Figure 20-2010] from the rod end. Mark the hoses for correct reassembly.

Install the cylinder(s) in the reverse order.

BobCat S70 – CYLINDER (LIFT) Testing

Open the rear door.

Remove the bolt (Item 1) [Figure 20-20-1] from the base end pin retainer (left side shown).

Use a slide hammer to remove the pivot pin (left side shown) [Figure 20-20-2].

Pull the cylinder forward. Mark the hoses for correct reassembly.

Check only one cylinder at a time.

Disconnect the hose (Item 1) [Figure 20-20-3] from the lift cylinder base end port.
Install a plug in the hose and tighten the plug.
Lower the seat bar, engage the parking brake and start the engine. Loaders without seat sensors press the green PRESS TO OPERATE button.
Push the top (toe) of the lift pedal until system relief pressure is reached.
If there is leakage from the open base end port of the lift cylinder, remove the lift cylinder for repair.