No tool is flawless. Users will run into a snag with one of them now or later. Same goes for Milwaukee M12 hammer drills too, and I’m sure that’s why you’re reading this in the first place.
Let’s not waste any of your time, then! I’ll jump right into the most common Milwaukee M12 hammer drill problems, along with details to help users with troubleshooting each of them.
But before you read this article, you can first watch my video about how you can troubleshoot the most common problems of the Milwaukee M12 Percussion drill.
First on the list is motor related problems and you can fix this by inspecting the motor and voltage supply.
If you have issues with the speed control, make sure the speed control latch is working.
My video also discusses how you can fix problems with its chuck, bearing and torque settings.
If you drill starts and stop, this is mostly due to overheating, just let it cool down.
Lastly, to avoid a jammed trigger/forward/reverse button, make sure there is no obstruction around.
Troubleshooting Common Milwaukee M12 Hammer Drill Problems
- Getting Too Hot To Handle!
High-impact tools like the Milwaukee M12 hammer drill are at a big risk of overheating. It’s a common issue because of how much force goes into doing the job these tools do.
While it may not sound like a big issue, overheating can eventually ruin entire hammer drills. It’s just a matter of how good users treat their tools, or how bad.
Overheating’s main cause is overworking. Overworking makes internal parts rise in temperature. This is a result of the motor and other parts of the drill having to work so hard.
Upon reaching a certain temperature, those very parts start to burn out. Fuses inside of them blow, circuit boards on the tool fry, wires burn, and other damages like that occur.
Other factors come into play too though. It’s not just using the tool too much that gets it hot. Using it in an environment that’s quite warm or storing it in hot places are also big reasons.
Avoiding these things is the first step to dealing with troubleshooting. As for what you should do once overheating happens? Well, there’s only one option.
Put the Milwaukee M12 hammer drill away for the time being. Don’t use it while it’s hot, because that’ll just make things worse. Put it in a room with normal temperature, and leave it for some hours.
- Light Comes On But Not Working
Does your Milwaukee M12 hammer drill’s light come on but it’s still not working? I looked online and saw a bunch of people mentioning that this happened to them.
Most of the time, the solution was pretty simple though. Since the tool’s light is coming on, we know it has power. Power isn’t of any use, however, when you can’t control the tool.
That’s exactly what happens if the trigger isn’t functional. So, remove the covers from the hammer drill. Get a better view of the trigger, and make sure that it isn’t dirty.
More often than not, it’s just a bunch of debris cluttering the trigger. It stops the trigger from pressing fully, blocking the input and stopping the Milwaukee M12 hammer drill from working.
After opening the covers, you can get a better look at the trigger and check this for yourself. Clean out the area around it, and that should do the job.
In rarer cases, the trigger mechanism itself may have a problem. These have to do with faulty springs that stop it from pulling back. For this, you have to replace parts to get the trigger to work again.
- Battery Flashing Red and Green While Charging
Where there’s a battery-operated tool, there are battery-related problems. It’s a part of every battery’s life cycle to get weaker, so issues are inevitable down the line.
One issue that users report with the Milwaukee M12 hammer drill is the battery making the charger flash red and green. It just keeps doing that instead of charging.
Most of the time, it’s either green or red that flashes. You can see that in the picture down there, where it’s only green flashing on my charger. But, this time, it’s both of them, so what’s up with that?
If you look at where I’m pointing in the photo above, you’ll see some signs near the indicator lights. There’s a sign there that explains the meaning of these red and green lights flashing together.
Basically, it’s an indicator to let users know the Milwaukee M12 hammer drill battery they’re trying to charge is dead, or heavily damaged. The charger can’t supply power to it.
So, to warn users, the charger flashes red and green. It’s best to not try charging batteries like these. You have to get a new battery, as this one is dead and can’t supply power to the hammer drill any longer.
I have also made a video on how to fix this issue, and you can watch it down below.
You would need another similar healthy battery to do this. Using two wires, connect the positive and negative terminals of the two batteries.
Leave the two batteries connected together for around 15 seconds and then disconnect them. Then, try to recharge it on the Milwaukee charger and it should now be charging properly.
And to help you more about battery related problems, I also have a video about the different meanings of light indicators on a Milwaukee charger. You can watch it below.
If you see a solid red, it means the battery is charging properly. This will turn into a solid green once it becomes fully charged.
And as mentioned previously, a flashing red and green indicates a bad battery. A flashing red meanwhile means a hot/cold relay.
- Milwaukee M12 Hammer Drill Not Spinning and Hammering
Sometimes, a Milwaukee M12 hammer drill just doesn’t want to work. Regardless of a full battery or whatever, it won’t start spinning and hammering, making the tool useless.
You’re not going to get any jobs done until that’s dealt with. Good news is, most of the time it’s pretty easy to do that. Both the common reason and common fix for this are surprisingly simple.
It has to do with the little speed select knob on top of the hammer drill, which you can see in the photo below this. That knob gets stuck between two levels at times.
When it’s between both levels, that likely causes some kind of confusion inside the Milwaukee M12 hammer drill. It stops it from spinning or hammering.
You just need to use force to push and pull the speed select around a little. That will take care of things and get the drill spinning again.
If adjusting the speed select doesn’t do anything though, and you’re certain the battery and drill bits aren’t problematic, I think there may be internal faults causing this.
Internal damages can stop the Milwaukee 12 hammer drill from spinning and hammering. The smallest of faulty components can ruin entire mechanisms inside the tool, stopping it from working.
If the warranty isn’t active and the tool is quite old, I’d recommend taking it to a shop for repairs. If it’s salvageable, you may be able to fix it and continue using the tool.
But, I think it’s better to replace the drill with a new one if you regularly use it. It’ll be a much better use of your money since new tools will last for years.
