307.5, 308, 308.5, 309, and 310 Mini Hydraulic Excavator Machine System Caterpillar

Illustration 1	g06353988
Left and Right Joystick

Illustration 2	g06180324
(1) Stick Out (2) Swing Right (3) Stick In (4) Swing Left (5) Boom Lower (6) Bucket Dump (7) Boom Raise (8) Bucket Close (9) HOLD

When you release the joysticks from any position, the joysticks will return to HOLD position (9). Movement of the upper structure will stop.

Two functions may be performed at the same time by moving a joystick diagonally.

The machine control pattern is initially set at the factory to the SAE system, as shown. The pattern on the left pertains to the left joystick and the pattern on the right pertains to the right joystick.

Note: The machine control pattern can be varied. Refer to Operation and Maintenance Manual, "Joystick Controls Alternate Patterns" for more information.

Illustration 3	g06354039
Right side view of main control valve

Movement of joystick (1) or joystick (2) is converted to a pulse width modulated signal (PWM). The PWM signal is received by the machine ECM. The ECM sends a signal to the solenoid valves that are mounted on the main control valve. The solenoid valves control the pilot oil flow that shifts the main control valve spools. The main control valve spools direct the flow of hydraulic oil to the implements. Pilot oil that enters the control valves causes the machine operations in Table 1.

Movement of the joysticks causes movement of the implements. Implement speeds and directions are proportional to the amount of movement of the joysticks.

Illustration 4	g06284245
Joystick base and schematic

Illustration 5	g06284264
Vertical slider joystick schematic