Hilti DX 76 Manual page 31

2. Regularly check all operating controls to ensure that they work properly.
3. Use the fastening tool only with suitable cartridges and the recommended energy setting → page 22.
▶ Use of the wrong cartridges or excessively high power settings can lead to premature failure of the
fastening tool.
8.3 Servicing the tool
Service the tool in the following situations:
1. If energy fluctuations occur (evidenced by irregularities in fastener penetration depth).
2. If cartridge misfires occur (the cartridge is not fired).
3. If the tool becomes noticeably less easy to operate.
▶ If the required contact pressure increases noticeably.
▶ If the trigger resistance increases.
▶ If the adjusting knob for driving energy has become difficult to turn.
▶ If the cartridge strip is difficult to remove.
8.3.1 Disassembling the fastening tool
WARNING
Risk of injury by accidental triggering! A loaded fastening tool can be made ready to fire at any time.
Accidental triggering can endanger you and others.
▶ Always unload the fastening tool (cartridges and fasteners) whenever you interrupt work with the fastening
tool.
▶ Before all maintenance, cleaning and setup activities, always make sure that there are no cartridges and
no fasteners in the fastening tool.
1. Make sure that the cycling grip is in its starting position (1).
▶ The marks on cycling grip and housing are in alignment.
2. Unscrew the fastener guide (3).
3. Remove the fastener guide with the piston from the piston guide.
4. Pull the piston out of the fastener guide (4).
5. Push the piston guide into the housing and unlock the piston guide with locking lever (2).
6. Pull the piston guide out of the housing.
8.3.2 Checking piston and stopper
WARNING
Risk of injury! A faulty buffer or piston or a faulty base plate leads to an increased risk of malfunctions.
▶ Check the piston and buffer for wear and replace them if damaged.
▶ Do not tamper with or modify the piston.
▶ Do not attempt to repair a faulty piston yourself, for example by grinding the tip.
1. The piston must be replaced in the following cases:
▶ The piston is broken.
▶ The piston is badly worn or chipped (e.g. a segment of the circumferential ring-shaped elevation at
the piston tip broken away).
▶ The piston rings are cracked or missing.
▶ The piston is bent (check by rolling the piston on a smooth, flat surface).
2. The stopper must be replaced in the following cases:
▶ The metal ring of the stopper is broken or detached.
▶ The stopper no longer holds on the fastener guide.
▶ The rubber is badly worn at certain points under the metal ring.
Observe the wear criteria applicable to important tool components, as listed in the "Care and
maintenance" section. → page 26
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