Haulotte Group HT21RT O, Maintenance Book

Page: 216 / 282

216 4000511390 E03.16 USA / GB
Upper boom
Procedure of dismantling / reassembling hydraulic rotary actuators
MS0028
7 - Testing the Actuator
N.B.-:-T
O AVOID CONTAMINATION TO MACHINED PARTS
: M
AKE SURE WORK AREA IS CLEAN
.
If the equipment is available, the actuator should be tested on a hydraulic test bench. The breakaway pressure ; the
pressure at which the shaft begins to rotate ; should be approximately 400 psi (28 bar). Cycle the actuator at least
25 times at 3000 psi (210 bar) pressure. After the *2 rotations, increase the pressure to *2 to check for leaks and
cracks. Perform the test again at the end of the rotation in the opposite direction.
7.1 - TESTING THE ACTUATOR FOR INTERNAL LEAKAGE
If the actuator is equipped with with a counterbalance valve, plug the valve ports. Connect the hydraulic lines to the
housing ports. Bleed all air from the actuator. Rotate the shaft to the end of rotation at 3000 psi (210 bar) and
maintain pressure. Remove the hydraulic line from the non-pressurized side.
Continuous oil flow from the open housing port indicates internal leakage across the piston. Replace the line and
rotate the shaft to the end of rotation in the opposite direction. Repeat the test procedure outlined above for the other
port. If there is an internal leak, disassemble, inspect and repair.
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.