Hilti DD 250 Manual De Usuario página 37

Malfunction
The drilling speed is decreas-
ing.
The handwheel can be turned
without resistance.
The diamond core bit can't be
fitted into the chuck.
Water escapes at the water
swivel or gear housing.
Water escapes from the
chuck during operation.
No water is flowing.
The drilling system has too
much play.
9 Disposal
Most of the materials from which Hilti tools and appliances are manufactured can be recycled. The
materials must be correctly separated before they can be recycled. In many countries, your old tools,
machines or appliances can be returned to Hilti for recycling. Ask Hilti Service or your Hilti representative
for further information.
Possible cause
The water flow rate is too low.
The carriage lock is engaged.
The shear pin is broken.
The core bit connection end or
chuck is dirty or damaged.
The water pressure is too high.
The rotary shaft seal is worn out.
The diamond core bit isn't securely
tightened in the chuck.
The core bit connection end /
chuck is dirty.
The seal at the chuck or at the
connection end is defective.
The water channel is blocked.
The diamond core bit isn't securely
tightened in the chuck.
The core bit connection end /
chuck is defective.
The connection between the dia-
mond core drilling machine and the
carriage or spacers is loose.
The carriage has too much play.
Screws / bolts on the drill stand are
loose.
The drill stand is inadequately fas-
tened.
Action to be taken
▶ Check the water supply to
the diamond core bit or,
respectively, increase the water
flow by adjusting the water flow
regulator.
▶ Release the carriage locking
mechanism.
▶ Replace the shear pin.
▶ Clean and grease the connec-
tion end and/or the chuck or
replace these parts.
▶ Reduce the water pressure.
▶ Replace the rotary shaft seal.
▶ Tighten the diamond core bit
securely.
▶ Remove the core bit. Rotate the
diamond core bit approx. 90°
about its own axis. Refit the
diamond core bit.
▶ Clean and grease the connec-
tion end and/or the chuck.
▶ Check the seal and replace it if
necessary.
▶ Increase the water pressure or
flush the water channel clear
from the opposite direction.
Clean the water inlet and outlet
aperture.
▶ Tighten the diamond core bit
securely.
▶ Remove the core bit. Rotate the
diamond core bit approx. 90°
about its own axis. Refit the
diamond core bit.
▶ Check the connection end and
chuck and replace them if
necessary.
▶ Check the connection and,
if necessary, refasten the
diamond core drilling machine.
▶ Adjust the play between the rail
and carriage.
▶ Check the security of screws
/ bolts on the drill stand and
tighten them if necessary.
▶ Fasten the drill stand more
securely.
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