M313C, M315C, M316C, M318C and M322C Excavators and M318C and M322C Material Handlers Hydraulic System Caterpillar

The overload warning device alerts the operator to excessive pressure in the boom cylinders, when the device is enabled by the rocker switch in the operator's compartment. Use this procedure to adjust the pressure switch for the overload warning system.

Table 1

Required Tools
Part Number	Part Description	Qty
8T-0859	Pressure Gauge (0 to 25,000 kPa (0 to 3,600 psi))	1
6V-3989	Fitting (TEST)	1
6V-4143	Quick Connect Coupler	2
6V-3014	Hose As	1

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Illustration 1	g00916873
Overload Warning Device (1) Pressure switch (Overload warning device) (2) Adjustment screw (3) Locking screw

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Illustration 2	g01206271
The remote pressure taps are located behind the left rear access door. (4) Pressure tap (Load sensing signal pressure)

1. Connect a 25000 kPa (3600 psi) pressure gauge to tap (4) .

2. Start the engine.

3. Adjust the engine speed to HIGH IDLE by turning the engine speed dial to position 10.

4. Place the overload warning device switch in the ON position.

5. Slowly move the right joystick to the BOOM RAISE position.

   Note: Stall the boom in the BOOM RAISE position or raise the boom with a load in order to activate the overload warning device.

6. The buzzer for the overload warning device should sound at a pressure reading of around 15000 to 16500 kPa (2175 to 2393 psi).

7. If the buzzer for the overload warning device does not sound, adjust the pressure setting for the overload warning device by utilizing adjustment screw (2) .

8. Loosen locking screw (3) .

9. Adjust the setting by turning adjusting screw (2) until the buzzer sounds at a pressure of around 15000 to 16500 kPa (2175 to 2393 psi).

10. Tighten locking screw (3) to the specified torque.