Loader Bobcat 773. Manual - part 15

When repairing hydrostatic and hydraulic
systems, clean the work area before
disassembly and keep all parts clean. Always
use caps and plugs on hoses, tubelines and
ports to keep dirt out. Dirt can quickly damage
the system.

I–2003–0888

Tightening Procedures

For tightening torques for hydraulic fittings,
tubelines etc., See Section 9. – Hydraulic Connection
Specifications.

HYDRAULIC SYSTEM INFORMATION

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773 BICS Loader

Service Manual

LIFT CYLINDER(S)

Checking The Lift Cylinder(s) For Internal Leakage

Lower the lift arms. Stop the engine. Pull up on the lift arm
bypass control and move the lift pedal to release the
hydraulic pressure. Raise the seat bar.

Check only one cylinder at a time. Disconnect the tubeline
(Item 1) [A] from the lift cylinder rod end port.

Lift the tubeline up for clearance. Disconnect the hose
(Item 1) [B] from the lift cylinder base end port (Item 2)
[B].

Install a plug in the hose (Item 1) [B] and tighten.

Reconnect the tubeline (Item 2) [A] to the lift cylinder rod
end port. Engage the parking brake. Lower the seat bar.
Start the engine and push the top (toe) of the lift pedal.

If there is any leakage from the base end cylinder port
(Item 2) [B], remove the lift cylinder for repair. Repeat the
procedure to check the other lift cylinder.

Removal And Installation

Stop the engine. Pull up on the lift arm by–pass control
and move the lift pedal to release the hydraulic pressure.
Raise the operator cab. (See Page 1–1.)

Disconnect the two hoses (Item 1) [B] from the lift
cylinder.

Remove the retainer bolt (Item 2) [A] & [C] and nut from
the pivot pin.

Installation: Tighten the retainer bolt and nut to 18–20
ft.–lbs. (24–27 Nm) torque.

Remove the pivot pin (Item 3) [A] & (Item 1) [C] from the
cylinder.

Slide the lift cylinder forward and remove it from the
loader.

Reverse the removal procedure to install the lift cylinder.

NOTE: Fuses may need to be moved for clearance.

Always clean up spilled fuel or oil. Keep heat,
flames, sparks or lighted tobacco away from
fuel and oil. Failure to use care around
combustibles can cause explosion or fire
which can result in injury or death.

W–2103–1285

Revised Jan. 99

Diesel fuel or hydraulic fluid under pressure
can penetrate skin or eyes, causing serious
injury or death. Fluid leaks under pressure may
not be visible. Use a piece of cardboard or wood
to find leaks. Do not use your bare hand. Wear
safety goggles. If fluid enters skin or eyes, get
immediate medical attention from a physician
familiar with this injury.

W–2072–0496

A

N–00819

1

2

3

773 BICS Loader

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Service Manual

C

N–15187

2

1

B

N–00820

1

2

Disconnect the hose (Item 1) [A] which goes to the base
end of the tilt cylinder.

Put a plug in the hose and tighten.

Install a test hose between cylinder and a drain pan.

Engage the parking brake. Lower the seat bar. Start the
engine and push the bottom (heel) of the tilt pedal. If there
is leakage from the open port, remove the tilt cylinder for
repair.

Removal And Installation

Remove the attachment. Roll the Bob–Tach forward and
lower the lift arms [B].

Place the Bob–Tach flat on a pallet to allow the tilt cylinder
base end pin enough clearance to be removed.

Stop the engine. Move the tilt pedal to release the
hydraulic pressure. Raise the seat bar.

Disconnect both hydraulic hoses (Items 1 & 2) [A].

Remove the retainer nut (Item 1) [C] from the rod end
pivot pin.

Installation:  Tighten the retainer nut to 18–20 ft.–lbs.
(24–27 Nm) torque.

Remove the grease fitting from the rod end pivot pin (Item
1) [D].

Remove the rod end pivot pin.

TILT CYLINDER

Checking The Tilt Cylinder For Internal Leakage

Remove the attachment. Roll the Bob–Tach fully back.
Stop the engine. Raise the seat bar.

Diesel fuel or hydraulic fluid under pressure
can penetrate skin or eyes, causing serious
injury or death. Fluid leaks under pressure may
not be visible. Use a piece of cardboard or wood
to find leaks. Do not use your bare hand. Wear
safety goggles. If fluid enters skin or eyes, get
immediate medical attention from a physician
familiar with this injury.

W–2072–0496

A

P–01187

1

2

C

P–03907

1

D

P–03904

1

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773 BICS Loader

Service Manual

B

P–00843

TILT CYLINDER (Cont’d)

Removal And Installation (Cont’d)

Remove the retainer nut (Item 1) [A] and bolt from the
base end pivot pin.

Installation: Tighten the retainer nut and bolt to 18–20
ft.–lbs. (24–27 Nm) torque.

W–2103–1285

Always clean up spilled fuel or oil. Keep heat,
flames, sparks or lighted tobacco away from
fuel and oil. Failure to use care around
combustibles can cause explosion or fire
which can result in injury or death.

Remove the base end pivot pin (Item 1) [B].

Remove the tilt cylinder from the loader.

Rod End Seal Replacement

Remove the old seal (both sides) from the rod end of the
tilt cylinder.

Apply a light coat of grease on the new seals (Item 1) [C].

Install the new seals with the lip facing in [C].

Use two pieces of shim stock (light cardboard), install the
rod end of the tilt cylinder into the Bob–Tach [D].

Be careful not to damage the new seals during
installation.

Reverse the removal procedure to install the tilt cylinder.

Revised Jan. 99

A

N–00847

1

C

P–03911

1

D

P–03910

773 BICS Loader

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Service Manual

B

N–00845

1