Digga HP450, Operator'S Manual, Page: 30 / 37

MAINTENANCE AND SERVICE
Now insert the seal into the gland from the inner end. Position the seal in
its groove, and release and remove the tool. Press the seal into its seat
the rest of the way by hand.
2. Install the new piston ring, rod wiper, O-rings and backup washers, if
applicable, on the piston.
Be careful not to damage the seals. Caution must be used when installing
the piston ring. The ring must be stretched carefully over the piston with
a smooth, round, pointed tool.
3. After installing the rod seal inside the gland, as shown in step #1, install
the external seal.
NOTE: Threaded glands may have been equipped with a separate O-ring and
backup washer system or a polypak (all in one) type seal. Current seal kits
contain a polypak (all in one) type seal to replace the discarded seal types on
ALL THREADED GLANDS.
4. Slide the gland onto the cylinder rod, being careful not to damage the rod
wiper. Then install the spacer, or flat washer (if so equipped), small o-ring,
piston, and hex nut onto the end of the cylinder rod.
5. Secure the cylinder rod (mounting end) in a vise with a support at its center.
Torque the nut to the amount shown for the thread diameter of the cylinder
rod (see chart).
IMPORTANT: Do not contact the active surface of the cylinder rod with the vise.
Damage to the rod could result.
6. Apply a lubricant (such as Lubriplate #105) to the piston and teflon ring. Insert the cylinder rod assembly
into the cylinder tube.
IMPORTANT: Ensure that the piston ring fits squarely into the cylinder tube and piston groove, otherwise the ring
may be damaged and a leak will occur.
7. Use a spanner wrench to rotate the gland clockwise into the cylinder. Continue to rotate the gland with the
spanner wrench until it is tight.
WARNING! CYLINDERS SERVICED IN THE FIELD ARE TO BE TESTED FOR LEAKAGE PRIOR TO THE
ATTACHMENT BEING PLACED IN WORK. FAILURE TO TEST REBUILT CYLINDERS COULD
RESULT IN DAMAGE TO THE CYLINDER AND/OR THE ATTACHMENT, CAUSE SEVERE
PERSONAL INJURY OR EVEN DEATH.
* 1" Thread Diameter WITH 1.25" Rod Diameter
Min. 230 ft. lbs. Max. 250 ft. lbs.
POUNDS - FEET
150-200
230-325
350-480
490-670
670-900
Thread Diameter
7/8"
* 1"
1-1/8"
1-1/4"
1-3/8"
Nm
203-271
311-440
475-651
664-908
908-1220
PM-000068-A DECEMBER 2017
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