Hilti DD 120 Mode D'emploi page 40

Fault
The service indicator lights.
The machine doesn't start and
the service indicator lights.
en
The machine doesn't start,
carbon brushes have been
changed, service indicator
lights.
The service indicator blinks.
The machine doesn't start,
drilling performance indicator
blinks red.
The machine doesn't start, theft
protection indicator blinks yel-
low.
The motor runs. The diamond
core bit doesn't rotate.
Drilling speed drops.
The handwheel turns but does-
n't engage.
Water escapes at the water
swivel or gear housing.
The diamond core bit cannot be
fitted into the chuck.
Water escapes from the chuck
during operation.
36
All manuals and user guides at all-guides.com
Possible cause
The carbon brushes are worn; the
machine will continue to run for a few
hours.
The carbon brushes are worn.
A fault has occurred in the power tool.
Motor speed error.
The machine has overheated.
The machine was overloaded for a
short time.
The power tool has not been un-
locked (tools with optional theft pro-
tection system).
Gear selector doesn't engage.
The gearing is defective.
The diamond core bit is polished.
The diamond core bit is polished.
Water pressure / flow rate too high.
The core is stuck in the core bit.
Maximum drilling depth is reached.
The diamond core bit is defective.
The slip clutch is disengaging prema-
turely or slipping.
The brake is engaged.
The water flow rate is too low.
The retaining pin is broken.
The water pressure is too high.
The shaft seal is defective.
The core bit connection end or chuck
is dirty or damaged.
The core bit is not screwed securely
into the chuck.
The core bit connection end / chuck
is dirty.
The chuck or connection end seal is
defective.
Remedy
The carbon brushes should be
changed.
See section: 8.4 Replacing carbon
brushes 10
Replace the carbon brushes.
See section: 8.4 Replacing carbon
brushes 10
If necessary, the power tool should be
repaired by Hilti Service.
Have the machine repaired by Hilti
Service.
Wait 90 seconds until the light goes
out. Switch the machine off and on
again.
Switch the machine off and on again.
Use the TPS key to unlock the power
tool.
Move the gear selector until felt to
engage.
If necessary, the machine should be
repaired by Hilti Service.
Sharpen the diamond core bit on a
sharpening plate with water flowing.
The wrong type of core bit has been
used. Seek advice from Hilti.
Reduce the water flow rate by adjust-
ing the flow regulator.
Remove the core.
Remove the core and use a core bit
extension.
Check the diamond core bit for dam-
age and replace it if necessary.
If necessary, the machine should be
repaired by Hilti Service.
Release the brake.
Adjust (open) the water flow regulator.
Check the water supply.
Fit a new retaining pin.
Reduce the water pressure.
The machine should be repaired by
Hilti Service.
Clean the connection end /chuck or
replace if necessary.
Tighten it securely.
Clean the connection end / chuck.
Check the seal and replace it if ne-
cessary.