Case 621G, 721G Wheel Loader Service Manual

Table of Contents

• Content
• Introduction
• Engine
• Transmission
• Four Wheel Drive System
• Front Axle
• Rear Axle
• Hydraulic System
• Brakes and Controls
• Hydraulic System
• Frames and Ballasting
• Steering
• Wheels
• Cab climate control
• Electrical System
• Front Loader and Bucket
• Platform, Cab, Bodywork and Decals
• Special Tool Index
• Electrical Schematics
• Hydraulic Schematics

Manual Extract: Arm – Repair

Pressure check
NOTE: this pressure is factory preset and is not adjustable.
1. Make sure that the temperature of the hydraulic oil is at least 54 – 57 °C (129.2 – 134.6 °F). The procedure to heat the hydraulic oil is the following.
● Check the oil temperature through the display in the cab (access to “Machine service – Sensor Status – Hydraulics” screens).
● Heat the hydraulic oil:
A. Start the engine and run at full throttle.
B. Hold the joystick in the ROLLBACK position while raising and lowering the lift arms from ground level to full height.

• To heat the hydraulic oil do the following:
A. Start the engine and run at full throttle.
B. Hold the joystick in the ROLLBACK position while raising and lowering the lift arms from ground level to full height.
C. Continue this procedure until the temperature of the hydraulic oil is 54 – 57 °C (129.2 – 134.6 °F) .

2. Raise lift arms to the top and turn off the engine. Turn the ignition key to the “RUN” position.
3. Repeatedly put the joystick into “FLOAT” position and back to neutral, as rapid as possible.
4. The system should allow a minimum of 10 actuations into float and still cause the lift arms to come down.