5
7. Heat the piston to Approximately
350
_
F with a torch or in an oven to
break the anaerobic adhesive. Insert
a spanner wrench in the drilled holes
on the piston face and break the seal
by rapping the wrench with a rubber
mallet, rotating the piston in a
counterclockwise direction.
On small cylinders, an alternate
method not requiring a spanner
wrench is to clamp the piston in a
soft jawed vice and turn the rod,
using an adjustable wrench on the
rod flats.
CAUTION
THE PISTON IS HOT!
8. Unscrew the piston and set it aside.
9. Remove the cushion collar from the
rod, if the cylinder is cushioned on
the head end. Let the rod cool before
re-assembly.
10. Snugly secure the rod into the vice.
Replace the cushion collar on the
rod (if required). Thoroughly clean all
metallic surfaces with a
non–petroleum based cleaner and a
wire brush, if necessary.
11. Apply anaerobic adhesive near the
rod shoulder (or collar) on the rod
threads and on the piston I.D.
threads.
NOTE
Be sure to follow the adhesive
manufacturer’s
recommendations regarding
surface preparation, priming
requirements, proper adhesive
for the thread size, and cure time
prior to pressurization. Failure to
do so could result in improper
sealing and retention.
12. Tighten the piston on the rod to the
torque listed in Table 3, using the
spanner wrench holes provided in
the piston.
13. Install new seals by placing one side
in the piston groove and stretching
the seal around the piston
circumference with the thin tool used
in disassembly. The elastomer
energizer should be installed in the
bottom of the groove before
installing the plastic face seal, as
shown in Figure 3.
Rod
∅
(in.)
Piston Torque
(ft. lb.)
(N.m)
5
/
8
30
40
1
40
54
1
3
/
8
40
54
1
3
/
4
50
67
2
100
135
2
1
/
2
135
180
3 & 3
1
/
2
250
340
3 & 3
1
/
2
250
340
4 & 4
1
/
2
400
540
4 & 4
1
/
2
400
540
5 & 5
1
/
2
550
740
5 & 5
1
/
2
550
740
Table 3.
Plastic face seal
Elastomer
energizer
Figure 3.
14. Cylinder body O–rings are easily
removed using a thin blade tool.
Care should be taken to avoid
damaging the surface finish in the
groove with the tool.
15. Metallic cushion sleeves can be
replaced by removing the snap ring
sleeve retainers.
Note the sleeve orientation in the
groove before removal. Some
sleeves are not symmetrical and
new sleeves must be installed in the
groove in the same orientation.
16. Shorter cylinders are more easily
assembled in a vertical position.
Insert the body O–ring in the cap
body groove and position the
cylinder body on the cap.
17. Snap the wear band on the piston
into the wide groove. Lubricate the
piston O.D. and seals. Carefully
insert the piston rod assembly into
the cylinder body. The body is
designed to easily accept the piston
with the sealing system in place.
18. Install the body O–ring in the head
body groove. When properly
installed, the O–ring should remain
in the head when inverted. Grease
will hold the o-ring in place if
required. Place the cylinder head
with tie rods on the body.
19. Repeat steps 6, 7 and 8 in
“Replacing rod seals” section.
20. Start the tie rod nuts until snug
against the head or cap and lay the
cylinder on its side. Secure the
cylinder horizontally into a vice or
clamped to a flat surface.
21. Tighten the tie rod nuts gradually in
a cross sequence pattern to equally
distribute forces around the cylinder
with a torque wrench. The required
torque values are listed in Table 4.
Check each nut a second time after
reaching full torque
Rod
∅
(in.)
Tie Rod Torque*
(ft. lb.)
(N.m)
1
1
/
2
14
19
2
33
45
2
1
/
2
50
68
3
1
/
4
105
140
4
150
205
5
340
460
6
570
770
7
840
1140
8
1120
1520
Table 4.
*Recommended torque values using
MoS
2
lubricant with 0.12 coefficient of
friction.
