Tools / Power Tools
Hilti AG 100-7S / 115-7S / 100-8S / 115-8S Angle Grinder Maintenance Guide
Essential maintenance and carbon brush replacement guide for Hilti AG 100-7S, 115-7S, 100-8S, and 115-8S angle grinders.
Table of contents
Product Overview
The Hilti AG 100-7S, AG 115-7S, AG 100-8S, and AG 115-8S are professional-grade angle grinders designed for demanding construction and metalworking tasks. These tools are engineered for durability and high performance, requiring regular maintenance to ensure longevity and safe operation. Users should always prioritize safety by wearing appropriate personal protective equipment, including eye protection and gloves, before operating or performing maintenance on the tool.
Safety Precautions
Before performing any maintenance, such as replacing carbon brushes, ensure the power tool is disconnected from the electrical supply. The tool features double insulation, indicated by the square symbol, which provides an extra layer of protection against electrical hazards. Always inspect the power cord and housing for signs of damage before use. If any damage is detected, the tool should be serviced by authorized Hilti personnel to maintain safety standards.
Carbon Brush Replacement
Regular inspection and replacement of carbon brushes are critical for the continued performance of the angle grinder. To replace the brushes, first remove the rear housing cover by unscrewing the securing screw. Carefully disconnect the brush leads using appropriate tools. Remove the worn brushes from their holders and insert new, genuine Hilti carbon brushes. Ensure that the springs are correctly positioned and that the electrical connections are secure. After replacing the brushes, carefully reassemble the housing, ensuring that no wires are pinched or damaged during the process. Tighten the housing screw firmly but do not overtighten, as this may damage the plastic casing.
Maintenance and Care
Keep the ventilation slots of the angle grinder clean and free of debris to prevent the motor from overheating. Use a dry brush or compressed air to remove dust accumulation. Avoid using harsh chemicals or solvents for cleaning, as these can damage the tool's plastic components. If the tool exhibits unusual vibrations, excessive sparking, or a loss of power, discontinue use immediately and contact a Hilti service center. Proper care and timely replacement of consumable parts will significantly extend the service life of your Hilti angle grinder.
Manufacturer information
Hilti Corporation
Practical help
Common problems
Excessive sparking
Check carbon brushes for wear and replace if necessary.
Tool overheating
Clean ventilation slots and ensure they are not obstructed by dust.
Loss of power
Inspect power cord for damage and ensure carbon brushes are making proper contact.
Before use
- Disconnect the tool from the power source before any maintenance.
- Wear eye protection and appropriate safety gear.
- Inspect the power cable for cuts or exposed wires.
- Ensure the housing is intact and screws are tightened.
- Verify that ventilation slots are clear of debris.
Images and diagrams
- Step 1-2: Removing the rear housing cover.
- Step 3-4: Disconnecting the old carbon brush leads.
- Step 5-7: Inserting new carbon brushes and securing the springs.
- Step 8-9: Reconnecting the electrical leads.
- Step 10: Ensuring proper wire routing to avoid pinching during reassembly.
Model compatibility
- Use only genuine Hilti replacement parts for the AG 100/115 series.
- Ensure the replacement brushes match the specific model requirements.
Manual page author
Emily Carter
User documentation editor
Prepares concise manual descriptions and highlights the most useful setup, operation, and maintenance information for readers.