Hilti DX 76 PTR Original Operating Instructions page 28

NOTE
Do not use a spray or steam/water jet system for cleaning!
Never operate the tool when the ventilation slots are
blocked. Do not permit foreign objects to enter the interior
of the tool.
8.2 Maintenance
Check all external parts of the tool for damage at regular
en
intervals and check that all controls operate faultlessly.
Do not operate the tool if parts are damaged or when the
controls do not function faultlessly. If necessary, the tool
should be repaired by Hilti Service.
Use the tool only with the recommended cartridges and
power settings. Use of the wrong cartridges or use of
excessively high power settings may lead to premature
failure of parts of the tool.
CAUTION
Dirt and residues in DX tools contain substances that
may be hazardous to your health. Do not inhale dust /
or dirt from cleaning. Keep the dust or dirt away from
foodstuffs. Wash your hands after cleaning the tool.
Never use grease for the maintenance/lubrication of
parts of the tool. This may lead to malfunctions. Use
only Hilti lubricant spray or a product of equivalent
quality.
8.2.1 Checking and replacing the piston and piston
brake
WARNING
All cartridges must be removed from the tool. All
nails must be removed from the nail magazine or the
fastener guide.
CAUTION
After the tool has been in use, the parts to be handled
may be very hot. It is essential that gloves are worn
if the following maintenance operations have to be
carried out before the tool has been allowed to cool
down.
NOTE
Firing the tool repeatedly without driving a fastener
stresses the piston and piston brake and causes these
parts to wear. If the piston shows signs of chipping and
/ or the synthetic rubber part of the piston brake is badly
worn, then these parts have reached the end of their life.
NOTE
The condition of the piston and piston brake must be
checked at regular intervals and at least daily.
NOTE
To replace the piston and the piston brake it is necessary
only to unscrew the fastener magazine or the fastener
guide. It is not necessary to remove the piston guide.
28
1. Unscrew and remove the fastener guide (or fastener
magazine).
2. Pull the piston out of the piston guide.
3. Check the piston for damage. If signs of damage
are found, the piston AND the piston brake must be
replaced. Check the piston brake for signs of wear
of the synthetic rubber part.
NOTE Check the piston for straightness by rolling it
on a smooth surface. Never use worn or damaged
pistons and do not attempt to manipulate or modify
the piston.
NOTE If the upper ring of the piston brake can be
turned easily toward the lower ring, the piston brake
is worn out and must be replaced.
4. If the piston has to be replaced, remove the piston
brake from the fastener guide.
5. Insert the new piston brake, the right way round, in
the fastener guide (or fastener magazine) that is to
be fitted to the tool.
NOTE Spray the opening in the piston brake with
Hilti lubricant spray.
NOTE The HVB fastener guide is equipped with a
piston stopper instead of a piston brake.
6. Insert the piston into the piston guide in the tool.
7. Screw the fastener guide (or fastener magazine) onto
the piston guide as far as it will go and then turn it
back until it engages.
8. Cycle the tool once with the cycling grip.
8.2.2 Cleaning the piston guide 9 19 20 21 22
WARNING
All cartridges must be removed from the tool. All
nails must be removed from the nail magazine or the
fastener guide.
CAUTION
After the tool has been in use, the parts to be handled
may be very hot. It is essential that gloves are worn
if the following maintenance operations have to be
carried out before the tool has been allowed to cool
down.
1. Check that the tool cycling grip is in its starting
position.
2. Unscrew and remove the nail magazine (or the
fastener guide).
3. Remove the piston from the piston guide and re-
move the piston brake from the nail magazine (or
fastener guide).
4. CAUTION It is essential that the tool is held
with the piston guide facing upwards. The piston
guide may otherwise fall out.
Open the piston guide release lever.