DRESSTA TD-25M EXTRA, Service Manual

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VALVES
SECTION 10B
Page 5
DRESSTA TD-25M EXTRA
CONTROL VALVE
5. INSPECTION AND REPAIR
1. It is recommended that new seal rings be installed whenever the control valve is disassembled
for service.
2. Make a preliminary inspection of all parts before cleaning to detect discrepancies which may
not show up once the parts are cleaned. Examine the oil for metal particles, dirt and other
foreign material.
3. Wash all the parts thoroughly in suitable solvent and dry with compressed air or a clean cloth.
6. REASSEMBLY
1. Install the port plug (12) with new O-ring (11) to the outlet cover (10) port. Position O-ring (11)
properly in its groove to prevent its damage. Torque the plug to 45 – 53 [Nm].
2. Install the relief valve (6) and port plug (4) with new O-ring (5) to the inlet cover plate (3).
Position O-ring (11) properly in its groove to prevent its damage. Torque the relief valve to
45 – 53 [Nm]. Torque the plug to 129 – 156 [Nm].
3. Oil the threads of the mounting studs (1) and install into the inlet cover (3).
4. ONE SPOOL CONTROL VALVE: Install the between section seals. Slide the blade lift section
(9) on the studs (1) up against the inlet cover (3).
5. THREE SPOOL CONTROL VALVE: Install the between section seals. Slide the blade lift
section (9), ripper lift section (8) and ripper pitch section (7) on the studs (1) up against the inlet
cover (3).
6. Install the outlet cover (3) on the studs (1) against the ripper pitch section (7). Oil the nut (2)
threads and install to the mounting studs (1). Tighten the stud nuts to 68 – 82 [Nm].
7. Install all hydraulic connectors previously removed.
NOTE: If the stud nuts are not tightened to the above specified torque value, valve spools seizure
or O-ring displacement can occur.
7. INSTALLATION
NOTE: Clean hydraulic system suction filter prior to valve installation.
1. Attach a hoist with a suitable sling to control valve (9, Fig. 10B.3) and position control valve on
machine. Install three bolts with washers (3, Fig. 10B.2 and 2, Fig.10B.4) and secure control
valve (8, Fig. 10B.3) to mounting bracket (4).
2. Reconnect lower pilot hoses (7) and upper pilot hoses (1) to control valve (9).
3. Reconnect outlet hoses (8) to blade lift section of control valve (9).
4. THREE SPOOL CONTROLVALVE: Reconnect outlet hoses (8) to ripper lift and pitch sections
of control valve (9).
5. Reconnect reservoir return tube (6) to control valve (9). Reconnect valve inlet hose (5) to
control valve (9). Reconnect hose (3) to inlet hose (5) hydraulic connector.
6. Install return filters (2, Fig. 10B.2).
7. Reinstall R.H. enclosure (2, Fig. 10B.1) with R.H. door (1) and secure it with bolts (3).
8. Refill the hydraulic system and vent it as described in the OPERATOR’S MANUAL.
9. Check the operation of the control valve by shifting the control levers into all operating
positions. Check and correct possible leakage.
10. Adjust the main pressure relief valve as described in SECTION 10, RELIEF VALVES
PRESSURE TESTS,. Close the door (1).