Quick answer
- Most of the time it's the battery, not the driver. Drop in a different charged M18 pack before you do anything else.
- Blow out and clean the battery contacts and the rails inside the tool. Sawdust and grit there fake a dead motor.
- Make sure the forward/reverse collar isn't parked in the center lock, which kills the trigger on purpose.
- If a hot tool just quit under load, let it cool. The M18 Fuel backs off when it overheats and comes back on its own.
What the symptom is telling you
"Not working" shows up a few ways on a Milwaukee impact driver, and each one points somewhere different. Dead silence with a charged battery usually means a contact or trigger problem. A tool that runs strong then fades points at a tired or hot pack. A fast clicking with no real rotation is often the anvil or a stuck bit, not the motor giving out. Sort out which one you've got and you stop chasing the wrong part.
Kill one myth first. The M18 Fuel drivers (the 2953-20 and its siblings) are brushless. There are no carbon brushes inside to wear out or swap, so any guide telling you to replace the brushes is written for an older brushed tool, not this one.
Start with the battery
This is the fix more often than not, so do it properly rather than guessing.
- Swap in a known-good pack. Put a different fully charged M18 battery in the tool. If it runs, the original pack is your problem and the driver is fine. Remember the platforms don't cross: an M12 battery won't fit an M18 tool, and the reverse is true too.
- Read the fuel gauge. Press the button on the pack. Dim lights, or a pack that won't show full after a long sit on the charger, means the cells are worn down.
- Mind the temperature. Lithium-ion won't charge below roughly 32°F (0°C). That's a normal safety interlock, not a defect. A pack left in a cold truck overnight may just need to reach room temperature before it'll take a charge or run.
- Seat it all the way. Push until it clicks hard. A battery that's a touch loose can read as stone dead.
Then clean the contacts
If a fresh battery doesn't wake it up, look at where the pack meets the tool. Pop the battery and check the terminals on both the pack and the rails inside the driver. Drywall dust, grit, and a little corrosion build up in there and break the circuit. Hit it with compressed air and gently clean the contacts. Don't pry or bend the terminals; bent rails cause more dead tools than dirty ones.
The button people forget
Check the forward/reverse collar above the trigger. It has a center detent that locks the trigger so the tool can't fire in your bag or on your belt. Parked halfway, the driver is dead by design and nothing you do at the battery will change that. Click it fully into forward or reverse and pull the trigger again. It feels too obvious to bother with, and it's caught plenty of people who were a phone call away from a warranty claim on a perfectly good tool.
While you're there, work the trigger fully a few dozen times. Milwaukee's variable-speed switches can get gummy, and a tool that only runs flat-out, cuts when you ease off, or fires intermittently usually has a worn or sticky switch rather than a bad motor. Cycling it sometimes frees a sticky one.
When it quit mid-job
If the driver died in the middle of heavy work and the housing feels hot, set it down for ten minutes. Sinking long fasteners into dense material trips the tool's thermal protection, and it returns by itself once the temperature drops. People mistake that pause for a failure and toss a good tool in the truck. A hot pack does the same thing at the charger, so give both time to cool before you judge them.
When it's genuinely dead
If a known-good battery, clean contacts, and a confirmed-forward collar still get you nothing, the failure is inside the tool, usually the switch or the electronic control module. Milwaukee runs a five-year warranty on these drivers, so check your purchase date before you open anything up. A tool still under warranty often gets repaired or swapped at a service center for nothing, which beats buying parts and fighting the housing yourself.