1. Introduction and Overview
This manual provides essential information for the proper installation, operation, and maintenance of the Chicago Pneumatic 8940158924 Quick Change Chisel Retainer. This accessory is designed to enhance the functionality and efficiency of compatible air hammers by allowing for rapid chisel changes.

Figure 1: Front view of the Chicago Pneumatic Quick Change Chisel Retainer.
2. Key Features
- Durable Construction: Expertly crafted from durable metal to ensure longevity and withstand demanding use.
- Quick Change Design: Facilitates seamless and rapid chisel swaps, improving operational efficiency.
- Ergonomic Shape: Designed for comfortable handling, which helps reduce operator fatigue.
- Balanced Design: Enhances control and stability during operation.
- Reliable Retention: Provides a secure hold for chisels, minimizing the risk of accidental ejection.
3. Compatibility
The 8940158924 Quick Change Chisel Retainer is specifically designed for use with the following Chicago Pneumatic air hammer models:
- CP7110 Air Hammer
- CP7160 Air Hammer
- CP7165 (Round) Air Hammer
Ensure your air hammer model is listed above for proper fit and optimal performance.
4. Setup and Installation
Follow these steps to install the Quick Change Chisel Retainer onto your compatible Chicago Pneumatic air hammer:
- Safety First: Disconnect the air hammer from its air supply before beginning installation.
- Remove Existing Retainer: If your air hammer has an existing spring-style retainer, carefully remove it according to your air hammer's instructions.
- Attach Quick Change Retainer: Slide the 8940158924 Quick Change Chisel Retainer onto the barrel of the air hammer. Ensure it seats properly.
- Secure Retainer: Use the provided set screw (if applicable) and an appropriate hex key to firmly secure the retainer to the air hammer. Ensure it is tightened sufficiently to prevent movement during operation, but do not overtighten. Some users recommend applying threadlocker to the set screws to prevent loosening from vibration.
- Verify Fit: Gently pull on the retainer to confirm it is securely attached to the air hammer.

Figure 2: View of the retainer's internal mechanism for chisel insertion.
5. Operating Instructions
Using the Quick Change Chisel Retainer is straightforward:
- Insert Chisel: Push the desired chisel bit into the opening of the quick-change retainer until it clicks securely into place.
- Verify Engagement: Gently pull on the chisel to ensure it is firmly seated and will not dislodge during use.
- Connect Air Supply: Reconnect the air hammer to its air supply.
- Operation: Operate the air hammer as usual, ensuring proper safety precautions are followed.
- Remove Chisel: To remove the chisel, pull back the collar of the quick-change retainer and withdraw the chisel bit.

Figure 3: Side view highlighting the set screw for securing the retainer.
6. Maintenance
Regular maintenance ensures the longevity and reliable performance of your Quick Change Chisel Retainer:
- Cleaning: Keep the retainer clean from debris, dust, and metal shavings. Use a clean cloth to wipe down the exterior.
- Lubrication: Periodically apply a small amount of appropriate lubricant to the moving parts of the quick-change mechanism to ensure smooth operation.
- Inspection: Regularly inspect the retainer for any signs of wear, damage, or corrosion. Check the set screw for tightness.
- Storage: Store the retainer in a clean, dry environment when not in use to prevent rust and damage.
7. Troubleshooting
If you encounter issues with your Quick Change Chisel Retainer, consider the following:
- Chisel Not Securing: Ensure the chisel shank is clean and free of obstructions. Verify that the retainer's internal mechanism is not jammed. Check for compatibility of the chisel with the retainer.
- Retainer Loosening: Re-tighten the set screw. Consider applying a medium-strength threadlocker to the set screw to prevent loosening due to vibration during operation.
- Difficulty Changing Chisels: Ensure the quick-change collar is fully pulled back when inserting or removing chisels. Lubricate the mechanism if it feels stiff.
- Excessive Wear: If the retainer shows significant wear or damage, it may need replacement to ensure safe and effective operation.
8. Specifications
| Attribute | Detail |
|---|---|
| Manufacturer | Chicago Pneumatic |
| Part Number | 8940158924 |
| Item Weight | 11.7 ounces |
| Product Dimensions | 6 x 3.5 x 1.5 inches |
| Model Number | 8940158924 |
| Size | One Size |
| Color | Silver |
| Style | Quick Change Chisel Retainer |
| Finish | Clear |
| Material | Metal |
| Power Source | Air Powered |
| Item Package Quantity | 1 |
| Included Components | Quick Change Chisel Retainer |
| Batteries Included? | No |
| Batteries Required? | No |
9. Warranty and Support
For information regarding warranty coverage, technical support, or replacement parts for your Chicago Pneumatic 8940158924 Quick Change Chisel Retainer, please refer to the official Chicago Pneumatic website or contact their customer service directly. Keep your purchase receipt for warranty claims.
You can visit the official Chicago Pneumatic store for more information: Chicago Pneumatic Store





