Doosan DX700LC Operation And Maintenance Manual page 232

Replace Hydraulic Oil Return Filter, Drain
Return Filter
NOTE: Change hydraulic oil return filter after first 250 hours
of operation or rebuild, and every 1,000 hours
thereafter.
NOTE:
If return filter clogged warning light (Figure 72) on
instrument panel comes "ON" the return filter must be
serviced.
The hydraulic oil will be hot after normal machine
operation. Allow the system to cool before attempting to
service any of the hydraulic components.
The hydraulic tank is pressurized. Lift the hydraulic
breather cap slightly to allow the pressurized air to vent.
After the pressure has been released, it is safe to remove
either the fill cap or service covers or drain water from the
tank.
IMPORTANT
Make sure to clean any dirt or water from the top of the
hydraulic tank, especially around the fill port and filter
ports.
1. Position the machine on firm, level ground. Lower the front
attachment to the ground and shut down engine.
2. Lift the breather cap (1, Figure 73) slightly to release the
internal pressure.
3. Remove bolts (2, Figure 73) and service cover (3).
Remove spring (4), valve (5) O-ring (6), and bypass
strainer (7), and then filter (8).
4. Remove filter and discard.
NOTE:
Used filter should always be disposed of
according to local regulations.
5. Install new filter and a new O-ring. Install bypass strainer,
valve and spring. Install service cover plate.
6. Tighten the breather cap (1, Figure 73).
7. Run engine for ten minutes at low idle to purge air from
circuit.
8. Check level in hydraulic oil tank (See page 4-15). Add oil if
necessary.
Inspection, Maintenance and Adjustment
4-44
WARNING
Figure 72
3
2
Figure 73
3
7
5
8
Figure 74
FG013832
1
FG016117
4 6
FG000761
OP001123