Haulotte Group HT21RT O, Maintenance Book

Page: 217 / 282

217 4000511390 E03.16 USA / GB
Upper boom
Procedure of dismantling / reassembling hydraulic rotary actuators
MS0028
8 - Installation and Bleeding
N.B.-:-T
O AVOID CONTAMINATION TO MACHINED PARTS
: M
AKE SURE WORK AREA IS CLEAN
.
After installation of the actuator on the equipment, it is important that all safety devices such as tie rods or safety cables
are properly reattached.
To purge air from the hydraulic lines, connect them together to create a closed loop and pump hydraulic fluid through
them. Review the OEM's operating manual and/or hydraulic schematic to determine which hydraulic lines to connect.
The linear feet and inside diameter of the hydraulic supply lines together with pump capacity will determine the amount
of pumping time required to fully purge the hydraulic system.
Bleeding may be necessary if excessive backlash is exhibited after the actuator is connected to the hydraulic system.
The OEM does not specify all actuators with bleed nipples ( A ), see the drawing below for their location. The following
steps are recommended when a minimum of 2 gallons ( 8 liters) is purged.
Avoid personal injury and machinery damage : Read the Service and Repair Manual for proper installation, maintenance
and repair procedure.
To avoid injury or damage to product : Secure produc to slotted table or vise.
Spraying fluids. Contents under pressure. Use caution when removing port plugs and fittings.
1. Connect a x 5 inside diameter 3/16" outside diameter x
5*16" clear, vinyl drain tube to each of the 2 bleed nipples.
Secure them with hose clamps. Place the vinyl tubes in a
clean 5 gal container to collect the purged oil. The oil can
be returned to the reservoir after this procedure is comple-
ted.
2. With an operator in the platform, open both bleed nipples
a 1/4 turn. Hydraulically rotate the platform to the end of
rotation (either clockwise or counterclockwise), and main-
tain hydraulic pressure. Oil with small air bubbles will be
seen flowing through the tubes. Allow a 1/2 gallon of fluid
to be purged from the actuator.
3. Keep the fittings open and rotate the platform in the oppo-
site direction to the end position. Maintain hydraulic pres-
sure until an additional 1/2 gallon of fluid is pumped into
the container.
4. Repeat steps 2 and 3. After the last 1/2 gallon is purged,
close both bleed nipples before rotating away from the end
position.