3
Inspection
9) Thoroughly clean the tube, the piston and the bottom.
10) Closely inspect the inside of the tube, the sealing
groove on the piston, the mechanical stop of the piston
(A) and bottom. There should be no scratches or dents
on the inside surface of the tube, the piston or the lock
ring grooves. If these parts are scratched or damaged
in any way then they should be replaced. Also never
use tubes with external pressure marks.
Assembly
11) Unpack the repair kit. Make sure the correct repair kit is
being used. Check to make sure that all parts are
contained in the kit by comparing the contents in the list
of page 2. If the repair kit contains 2 plastic bags, use
the one that pictures the bottom of your gas spring and
discard the other. Discard all parts that are to be
replaced with new ones from the repair kit.
12) First fit the scraper (B) into the top of the tube. Make
sure the scraper sits correctly in the groove with the lip
pointing upwards.
13) Mount the Flex ring (C) and the piston seal (D) with the
O-ring facing downwards (gas side).
14) Mount the O-ring (G) to the bottom. Make sure it is
fitted in the square groove. If backup ring is present in
the repair kit (see 11) it should be in the same groove
together with the O-ring, opposite of the O-ring gas
side.
15) Clamp the tube with the lock ring groove facing
upwards securely in the vise. Oil the seals on the
piston and upper part of the tube and then tapping it
down carefully, using a socket and mallet. Making sure
all of the stroke length becomes exposed.
16) Fill the spring with the appropriate oil volume (see table
to the right).
17) Oil the O-ring (G) on the bottom. Tap down the bottom
(H) carefully into the tube until the lock ring groove is
exposed using the socket and plastic mallet.
Note! Make sure not to pinch the O-ring while
tapping down the bottom.
18) Fit the lock ring (I) into the lock ring groove by pushing
one of the ends into the groove, then either press or hit
the other until it snaps into the groove.
Note! Use a T-handle to pull up the bottom in case
the bottom falls down into the tube. Use a T-handle
extension if needed.
19) Pull out the bottom (H) using a T-handle until the
bottom and the tube are flush.
Warning! If the bottom and the tube are not flush,
the assembly is incorrect. DO NOT charge the
spring. Charging an incorrectly assembled spring
could result in serious injury.
20) Mount the valve (F) into the charging port using the
valve tool. Tighten only finger tight. The gas spring is
now ready for charging.
For gas charging see Gas Charging Instruction
8200-1873 available at kaller.com
Model
Stroke Length [mm]
Oil [ml]
CU4 740
6 - 25
2
32 - 50
3
CU4 1000
6
1
10 - 32
2
40
4
50
6
CU4 1800
6 - 25
4
32 - 40
6
50
– 65
10
CU4 2900
10
– 16
4
25
– 32
6
40
– 65
10
CU4 4700
10
– 25
6
32
– 40
10
50
– 65
15
CU4 7500
10
– 25
10
32
– 40
15
50
– 65
20
CU4 11800
10
– 25
20
32
30
40
40
50
– 65
50
CU4 18300
10
– 25
30
32
40
40
– 50
50
65
60
