TROUBLESHOOTING
46
7 TROUBLESHOOTING
The operational failure table below shows the possible most common faults, their causes, and the
measures that can be taken so the interference can be eliminated.
7.1.1 Safety instructions
* When carrying out repairs and measures to remove the cause of the failure, all the instructions
issued on the crane operation and safety should be strictly adhered to.
FAILURE
POSSIBLE CAUSE OF THE
FAILURE
MEASURE
The crane does
not move
- There is no oil in the tank
- Pressure connection is not con-
nected or is faulty
- The pump does not build up
pressure
- Add oil
- Check the connection and replace a new
quick coupler if necessary
- Measure the pressure from the pressure
end of the control valve , check the pump
pressure relief valve
The crane moves
a little bit, or is
powerless
- Return connector is not connect-
ed or is faulty
- The main release of the crane or
pump pressure relief valve is faulty
or dirty
- Check the connection, measure the re-
turn pressure
- Measure the pressure from the pressure
end of the control valve , if necessary
replace the pressure relief valve
One option is
powerless
- The spool specific pressure re-
lease valve is faulty or dirty
- Measure the pressure of the relevant
operation and replace with a new pres-
sure relief valve if necessary
The boom is low-
ered at normal
load
- the pressure relief valve of the
relevant operation is leaking
- Cylinder seal is leaking
- The valve spool is leaking
- Replace the pressure relief valve
- The functionality falls under the load and
the cylinder heats up when putting a load
on it.
- Replace the seals
The hydraulic
system is heating
up
- The pump is worn loose
- Pump capacity too large for the
valves in question
- Too little oil in the hydraulic sys-
tem
- Measure the pressure when the oil is
hot. If necessary, replace the pump
- Measure the return pressure, adjust the
flow rate to less
- Add oil
- The valve
spools are sticky
- Overheated hydraulic oil
- Impurities in the valve
- The studs connecting the valve
blocks are too tight or too loose
- See the previous item
- Check whether the oil and filters are
changed according to the recommenda-
tions
- Check the tightening torques
The turning de-
vice body drains
the oil
- Cylinder seal of the turning de-
vice is leaking
- Too much grease in the turning
device
- The shaft seal is leaking
- If necessary, replace the seals (seals
may leak a little oil go a little past, when
the oils are very cold)
- Tighten by turning the spring of the shaft
seal, replace the shaft seal if necessary
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