HYDRAULIC SYSTEM
ME12002
Checking the Pressure Drop
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 page 65. 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 page 65 and steps 1 through 3 of this section. Checking the Pilot Pressure Pump P3 (A3)
Functions: Hydraulic pilot control system. Checking the Gear Pump Setting P3 (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.
909768/BP1207
66
Printed in U.S.A
