If you are unsure about completing the repair yourself, remember that Hilti offers a renowned and repair service. If your tool is still within its 2-year "no-cost" wear-and-tear period, avoid opening the casing entirely, as DIY disassembly can void your factory warranty.
Scroll down to the product documents or "Technical Data" section. hilti sid 4 a22 parts diagram free
If you are looking for a , tell me which section of the tool (e.g., the chuck , motor , or switch ) is failing so I can find the exact part number for you. Operations Manual - SID 4-A22 If you are unsure about completing the repair