HYDRAULICSYSTEMME12002

CheckingthePressureDrop

NOTICE:The pressure drop check procedure only measures main pressure limiting valve functions.

1.The pressure drop for each function should not exceed more than 10% of the setting (approximate value: only applicable to primary pressure limiting values). An excessive pressure drop might indicate leakage.

2.Check the pressure setting and the pressure drop function: dipper arm (rod side), bucket cylinder (rod: bottom side) and boom cylinder (rod: bottom side). For drive left/right (forward/rearward) and auxiliary hydraulics, see “Checking the Primary-pressure Limiting Valve 1 (MR) Setting” on page65.

3.If any settings deviate from factory settings, set the correct pressure at the primary pressure limiting valve (MR) at the main valve block and check the reason for the pressure drop.

4.Complete the steps in “Checking the Primarypressure Limiting Valve 1 (MR) Setting” on page65 and steps 1 through 3 of this section.

CheckingthePilotPressurePumpP3(A3)

Functions: Hydraulic pilot control system.

CheckingtheGearPumpSettingP3(A3)

1.Apply the pressure gauge at measuring point MP4.

2.Actuate joysticks.

3.Check the pressure level and/or set it at the pressure limiting valve on the gear pump.

NOTICE:Refer to the Pressure Checklist located on the following pages.