Dake Elecdraulic II - 908 series - Manual (Page 2)

Model 8-025, 8-050, 8-075 & 8-150 2
4. The relief valve located in the manual valve has been set at the factory to open at the maximum
tonnage of the press. The valve can be adjusted by removing the hex cap nut located on the lower left
hand front corner of the manual valve. Turning the adjusting screw counterclockwise lowers the
setting.
MAINTENANCE
CAUTION: When disconnecting any parts of this machine be extremely careful that all parts are clean
to prevent entrance of dirt in the hydraulic system.
1. If press loses Pressure:
a. Check all tubing joints for leaks and tighten the tube nuts.
b. Trouble shoot throttling 4-way valve. Refer to bulletin on Dynex throttling 4-way valve.
c. Worn cup leather (Serial No < 192522) or T-ring seal (Serial No > 192523). If none of the
previous conditions seem to have been the cause of the trouble, the cup leather or T-ring seal
may be worn out or damaged. To inspect this it is necessary to drain the oil and remove the
workhead from the press frame. Remove tube assembly (Item No. 48 & 49). Insert a rod into
the hole located on the top side of cylinder and unscrew workhead assembly from frame. Insert
rod into the hole on piston guide (item 47) and unscrew from cylinder. Remove piston from
cylinder. The cup leather or T-ring seal can now be inspected and replaced if necessary. Also
at this time, inspection of rod seal (item 44) and O-ring seal (item 43) is recommended.
Replace if necessary in reverse order being careful not to damage the T-ring seals and O-ring
seal.
2. If press will not develop rated tonnage.
a. Relief valve not set properly. This valve is located in the lower left hand front corner of the
manual valve. The valve has been set at the factory to by-pass oil from the pump back to the
reservoir when the pressure reaches rated capacity. To expose the relief valve for adjusting
remove the control handle ball (item 53), the control panel (item 57), and the hex cap nut. The
load on the spring which governs the pressure at which the valve will by-pass is adjusted by
turning the adjusting screw clockwise to raise the setting. Replace the hex cap nut, control
panel, and control handle ball after adjusting. The relief valve should not be tampered with after
it is once set at the capacity of the press.
b. Trouble shoot throttling 4-way valve. Refer to bulletin on Dynex throttling 4-way valve.
c. Worn cup leather or T-ring seal (see Section I, item C above)
3. If nothing happens when press is operated.
a. If motor does not run, the electrical circuit should be investigated.
b. If the ram will come down only a fraction of its rated stroke, check the oil level in the reservoir
with the ram at the top of its stroke. Oil should be visible when the oil level plug located on the
rear of the reservoir is removed.
4. If press is operating slow, check for use of improper oil. It is essential that the recommended oil, Mobil
DTE 24 or equal be used. Heavier oils cause marked reduction in the ram speed. DO NOT USE
HYDRAULIC JACK OIL!
5. If press builds pressure and is not contacting the work on the down stroke, the rated extended stroke
may be exceeded.
6. If press builds pressure on the return stroke the rated retract stroke may be exceeded.
CAUTION: Prolonged building of pressure at each end of the piston stroke may damage the
workhead.
CAUTION : When disconnecting any parts of this machine be extremely careful that all parts are
clean to prevent entrance of dirt in the hydraulic system.