Haulotte Group HT21RT O, Maintenance Book

Page: 205 / 282

205 4000511390 E03.16 USA / GB
Upper boom
Procedure of dismantling / reassembling hydraulic rotary actuators
MS0028
8. Remove the stop tube ( 400 ) if the actuator is equipped
with one. The stop tube is an available option that limits
the rotation of the actuator.
9. Every actuator has two sets of small punched timing
marks that indicate timing between the gear sets. The lo-
cation and appearance of the marks can vary slightly
between models. One set indicates the timing between
the piston sleeve ( 3 ) and the housing ( 1 ) (photo at left),
the second set between the piston and the shaft (lower
photo). To ensure correct rotation and accurate end posi-
tions, it is essential that the actuator be correctly timed
when it is reassembled. The punched timing marks can
be used, but it is easier to highlight punched marks with a
marker before disassembly as outlined in the steps below.
10. Prior to removing the shaft ( 2 ), use a felt marker to clearly
indicate the timing between shaft and piston sleeve ( 3 ).
This will greatly simplify timing when the actuator is reas-
sembled.