Hydraulic Control Value - Doosan D35S-5 Disassembly/Assembly

Hydraulic Control Value

Disassembling
Keep following precautions for disassembling.
1. The main equipment has to be leveled, with all
the working units grounded, engine stopped, and
the actuator has to be depressurized. If
disassemble the actuator while it is pressurized,
high pressure oil or part may ejected out which is
very dangerous.
2. Release the air pressure in tank(for pressurized
tanks)
3. Clean up the surroundings of the part to be
disassembled, and take care that foreign matter
does not enter the valve.
4. Mark the disassembled parts or arrange them on
work bench in the order of assembly in order not
to confuse the order of assembling.
5. Replace all the seals(O-rings, back-up rings)
which were disassembled with new seals.
6. Since the spool is matched with the valve housing
by clearance control, it is not replaceable for
quality. Protect it from impact of falling down.
7. Protect the sealing faces of the fitting surfaces in
all sections from impact or scratch.
8. In order to minimize internal leak, the clearance of
spool is kept as small as possible. Disassembling
and assembling the spool may deform the spool.
Therefore, full assembly replacement, when
necessary, is recommended.
Refer to the attached Parts List for the dimensions
and torques of the screws and plugs related with the
disassembling.
Disassembling Valve Assembly
The assembling number shall be in compliance with
the attached Assembly Parts List: Representative
Parts No. C0240-41001.
1. Place the valve assembly on level work table, with
the mounting side down. Remove the nuts(1) and
(3) for the tie rod, at the end of the outlet section.
Vehicle Systems
2. Slowly remove each spool section assembly in
the reverse order as in the outlet section.
Take care not to lose poppet, springs, or o-rings in
the fitting face of each section.
3. Remove the tie rods (2) & (4) from the inlet
section assembly.
Disassembling the Inlet Section
Assembly
The combination number shall be in accordance
with the attached Part List No. C0213-41001.
Fix the unit on the vise softly, covering the fitting
face of the inlet section assembly to prevent
damage.
1. Remove socket head bolt(14), remove cap(13),
and remove the spool(2) in sub-assembly state
from the inlet housing(1). The seal plate(5),
wiper(4), and O-ring(3) on the cap(13) side have
to be remain affixed to the spool(2)
【Cautions for Removing Spool 】
When removing the spool, take it out correctly to
prevent dent or scratch. Dent or scratch may harm
the housing hole when removing the spool, or may
make it impossible to reinsert the spool, or may
cause malfunction even able to be inserted. Each
spool has to be marked and arranged on work
bench, etc., to prevent confusion in reassembling. If
assembled wrong, the actuator will fail to operate
properly, which may cause serious danger.
【Fig. 2 – 1 】
15 Disassembly & Assembly