Introduction
This manual provides essential instructions for the safe operation, maintenance, and troubleshooting of your Milwaukee M18 Cordless Electric Grease Gun. Please read this manual thoroughly before using the tool to ensure proper function and to prevent injury or damage.
The Milwaukee M18 Cordless Electric Grease Gun is designed for efficient and precise lubrication in various applications, utilizing the M18 REDLITHIUM battery system.
General Safety Instructions
WARNING: Read all safety warnings, instructions, illustrations, and specifications provided with this power tool. Failure to follow all instructions listed below may result in electric shock, fire, and/or serious injury.
- Always wear eye protection.
- Keep work area clean and well lit. Cluttered or dark areas invite accidents.
- Do not operate power tools in explosive atmospheres, such as in the presence of flammable liquids, gases, or dust.
- Keep children and bystanders away while operating a power tool. Distractions can cause you to lose control.
- Use the correct tool for your application. Do not force the tool.
- Disconnect the battery pack from the tool before making any adjustments, changing accessories, or storing power tools.
- Store idle power tools out of the reach of children and do not allow persons unfamiliar with the power tool or these instructions to operate the power tool.
- Maintain power tools and accessories. Check for misalignment or binding of moving parts, breakage of parts, and any other condition that may affect the power tool's operation.
- Use the power tool, accessories, and tool bits in accordance with these instructions, taking into account the working conditions and the work to be performed.
Setup
1. Unpacking
Carefully remove all components from the packaging. Inspect the tool for any signs of damage that may have occurred during shipping. Retain packaging materials for future storage or transport.
2. Battery Installation
- Ensure the grease gun is turned off.
- Align the battery pack with the battery port on the tool.
- Slide the battery pack into the port until it clicks securely into place.
- To remove, press the release button on the battery pack and slide it out.
Note: Batteries are sold separately. Use only Milwaukee M18 REDLITHIUM battery packs.
3. Loading a Grease Cartridge
There are two primary methods for loading grease:
Cartridge Loading:
- Unscrew the barrel assembly from the grease gun head.
- Pull the plunger rod all the way back and lock it into the notch on the end cap.
- Remove the plastic cap from one end of a standard 14 oz grease cartridge.
- Insert the open end of the cartridge into the barrel.
- Remove the pull-tab seal from the other end of the cartridge.
- Screw the barrel assembly back onto the grease gun head until hand-tight.
- Release the plunger rod from the notch.
Bulk Loading (Optional):
For bulk loading, refer to the detailed instructions in the full manufacturer's manual or consult a qualified technician. This method typically involves using a bulk filler pump.
4. Priming the Pump
After loading a new cartridge or if the gun has been stored, it may be necessary to prime the pump to remove air pockets.
- Point the nozzle into a waste container or rag.
- Press and hold the trigger.
- If grease does not flow, slightly loosen the barrel assembly from the head until air escapes, then re-tighten. Repeat if necessary.
- Continue holding the trigger until a steady stream of grease emerges.

Image: Milwaukee M18 Cordless Electric Grease Gun. This image shows the main unit, highlighting the battery port and grease barrel.
Operating Instructions
1. Basic Operation
- Ensure the grease gun is properly loaded and primed.
- Attach the coupler to the grease fitting on the component to be lubricated. Ensure a secure connection to prevent leakage.
- Press the trigger to dispense grease. The amount of grease dispensed depends on how long the trigger is held.
- Release the trigger to stop the flow of grease.
- To remove the coupler from the fitting, tilt it slightly and pull firmly.
2. Flow Rate Control (if applicable)
Some models may feature a variable speed trigger or a flow rate selector. Consult your specific model's features for precise control over grease output.
3. LED Work Light
The integrated LED work light illuminates the work area for improved visibility. It typically activates when the trigger is pressed.
Maintenance
1. Cleaning
- Always disconnect the battery pack before cleaning.
- Wipe down the exterior of the tool with a soft, damp cloth. Do not use harsh chemicals or abrasive cleaners.
- Clean any excess grease from the nozzle and coupler after each use to prevent clogging and ensure proper function.
2. Storage
- Store the grease gun in a clean, dry place, away from direct sunlight and extreme temperatures.
- Remove the battery pack from the tool before storing for extended periods.
- If a grease cartridge is partially used, it can remain in the gun for storage, but ensure the plunger rod is engaged to prevent leakage.
3. Battery Care
- Charge battery packs using only the charger specified by the manufacturer.
- Do not store battery packs in locations where the temperature may reach or exceed 122°F (50°C).
- Do not incinerate battery packs, even if they are severely damaged or completely worn out.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No grease flow | Air pocket in pump; Empty cartridge; Clogged nozzle/coupler; Dead battery | Prime the pump; Replace cartridge; Clean nozzle/coupler; Charge/replace battery |
| Grease leakage from barrel | Barrel not tightened; Damaged O-rings | Ensure barrel is hand-tight; Inspect and replace O-rings if damaged |
| Tool not turning on | Battery not inserted correctly; Battery discharged; Tool malfunction | Re-insert battery; Charge battery; Contact Milwaukee service |
Specifications
- Brand: Milwaukee
- Model: M18 Cordless Electric Grease Gun
- Power Source: M18 REDLITHIUM Battery (sold separately)
- Grease Capacity: 14 oz. standard cartridge
- Item Weight: 9.25 pounds (tool only, approximate)
- Manufacturer: MILWAUKEE ELECTRIC TOOL CORP
- ASIN: B07XVNNXLT
Warranty and Support
Milwaukee power tools are backed by a limited warranty. For detailed warranty information, registration, or to locate an authorized service center, please visit the official Milwaukee Tool website or contact their customer support directly.
Official Website: www.milwaukeetool.com
Note: Warranty terms and conditions may vary by region and product. Keep your purchase receipt as proof of purchase.







