My makita angle grinder is making a crackling sound I replaced the brushes, but it is still making the same sound

It sounds like the armature is shot. When the armature goes bad you will see excess sparking from the brushes.

You can try removing brush covers and brushes to check and clean as needed.I have a makita grinder and have to change brushes about every two years but I use mine a lot in very dusty conditions.I think that I would probably check on/off switch about first as I have had mine do exactly what you have and I replaced the switch and it's still working.I have had mine for 15 years.Great little grinders. If you feel comfortable doing so you can bypass swith to make sure motor is good. Best of luck and thank you.

first unplug the tool, next on the backside you will notice a screw, remove it and slide the cover back to expose the backside of the motor. gently move the springs that hold the brushes tight to the side and remove the brushes and replace. Make sure to replace the springs and then slide the cover back into place and replace the screw and that should take care of your problem.

Hi,
Yes, that is usually the brushes, they need to be replaced...

heatman101

Sounds like your brushes are used up. Take the brush caps off on each side of the grinder handle, if the carbon is 1/8" long or shorter they have to be replaced. (Makita Part #191938-1) If you overworked the tool (put too much pressure on while grinding) it's possible the armature and/or field overheated and burned out. They are Makita Part #517301-4 and #521621-0 respectively. You need a growler to check these items to see if they're shorted out.

check inside for any loose connections plus check the brushes. if like you say it is smoking it could be a trip to the wheelie bin for that one.

Yes, the rock dust is what's destroying your brushes and armatures. It gets sucked into the rear vent slots and gets to those parts and eats them away quickly. I don't know of any vacuum systems make by Makita but there are some companies that make them for their systems. Blastrac is one that comes to mind but they can be real expensive systems. I don't know of any grinders with sealed brush/armature systems, they have too much heat to disipate. To make your Makita grinders last longer make sure you are cutting with the side of the blade that directs the dust away from the case and try to have a strong airflow blowing the dust away from the grinder to minimize the dust taken in at the back of the grinder.

sounds like it needs new brushes

The brushes for that grinder are Makita Part #194074-2. They can be found on sites like www.ereplacementparts.com.

Take apart the rear portion of the case -- the part the cord enters -- two halves -- screws in side -- you'll see the brushes -- they are in holders held in by springs and plug into the winding.