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9.7 POSSIBLE FAULTS AND RELEVANT REMEDIES
Fault
Vibrations in hydraulic cylinder and jerkin-
gs at the first manoeuvres.
Vibrations with every functions when the
oil is hot.
Remedy
Perform manoeuvres without loads for
some minutes to warm the oil up.
Add hydraulic oil to the tank.
Operate the control lever carrying the
cylinders to stroke end for some times in
both directions.
Cause
The temperature of the hydraulic oil is
too low.
Lacking of oil in the tank. Air in the hydrau-
lic system.
All the crane movements are very slow,
even when unloaded.
The hydraulic extension are not exten-
ding in the right sequence.
Crane rotation not regular.
The crane does not lift the loads of the
load chart table.
The crane lift the load, but cannot hold it.
Noise coming from articulation points.
The hydraulic legs does not hold under
load.
Suction hose from oiltank crushed or
obstructed.
The pump is drawing in air.
Bad lubrication.
Sliding pads are worn.
Sequence valve on extension cylinder
has to be adjusted.
The truck is not correctly levelled.
Worn slewing motor.
Defective pump.
Uncorrect settings of the valves.
Hydraulic cylinder sealings are worn.
Uncorrect settings of the valves.
Hydraulic cylinder sealings are worn.
Lacking of lubrication.
Defective holding valves.
Worn sealings in the stabilizer cylinder.
Replace or clean the suction hose.
Check that the relevant fittings are well
tightened.
Grease the extensions.
Replace sliding pads.*
Adjust the sequence valve.*
Level the truck.
Replace slewing motor.
Replace the pump.*
Adjust valve settings.*
Replace worn sealings.*
Adjust valve settings.*
Replace worn sealings.*
Grease articulation points.
Clean or replace holding valves.*
Replace worn sealings.*
The DC electric motor does not run.
DC electric motor overheating.
The crane locks with boom lifted at end
course.
Truck battery discharged.
Electric connections are damaged.
Burned fuses.
Motor windings are burnt.
Too long running time.
Pressure transducer not set.
Setting of general max. pressure valve
too high.
Charge battery.
Check electrical wirings, terminals, con-
nections and their integrity.
Replace fuses.
Replace the electric pump.
Running periods are to be shortened and
their intervals to be elongated.
Disassemble the casing and move ma-
nually the boom descent valve (EV2B).
Reduce the general max. pressure valve
(pict.11)
