Very often, a manufacturer of angle grinders completes their products with a spare pair of brushes (graphite contacts that allow electric current to be transmitted to a rotating rotor).
Is this part so worn out so intensively that it is only intended to add it? If you use the tool from time to time, then the brushes will survive the owner. But if you operate the angle grinder daily, then, indeed, their wear will be significant. And the day will come when a few-centimeter graphite rod will be erased to a thin plate. Extreme wear of the brushes must not be allowed so as not to damage the rotor contacts. It is necessary to check the condition of the rods periodically, after operating hours of dozens of hours.
This is where a sensible question arises for manufacturers of grinders, why not make a window of transparent plastic in the case in order to visually assess the condition of graphite contacts without analyzing the power tool (in some models of grinders it is not necessary to unscrew the case)?
Attention! When starting to replace the brushes, as with any penetration into the body of the power tool, it is necessary to turn off the power supply by removing the plug from the outlet.
In view of the structural diversity of angle grinders, the replacement of graphite contacts for each model of tool may have its own characteristics.
The most elementary way, without disassembling the case
Some manufacturers have come to the possibility of replacing the brushes very rationally. There are screw plugs in the machine body. And the whole process of checking or “repairing” takes two minutes (for both graphite contacts):
- Unscrew screw plug.
- Pry off the pressure cap with a thin screwdriver and remove the brush.
- If the brush has lost 70. 80% of the length compared to the new one, then it should be replaced. Otherwise, the old graphite contact must be placed on the same side as it was before extraction, in order to exclude the grinding process. After all, the brushes wear out unevenly due to the fact that they are in contact with a rotating cylindrical surface.
- Screw the plug all the way. Attention! The cork can be screwed upside down. Therefore, it is necessary to ensure that the groove for the screwdriver is on top. Otherwise, the next unscrewing will cause difficulties.
- Repeat all steps with the brush located on the back side of the case, an angle grinder.
This is the easiest way to replace the brushes on an angle grinder, without disassembling the case. Therefore, when buying a new instrument, this nuance can be taken into account.
angle grinder without rear handle
For grinders that do not have a rear handle, the brushes are replaced in the following sequence:
Video: How to Change Brushes to an Angle Grinder
- Unscrew the angle grinder from the end face.
- Pull off protective cylinder cover.
- Pull cover off contact block.
- Pry off the brush pressure cap with a thin screwdriver and pull out the graphite rod.
- Insert a new brush, close the contact block with a cover.
- Repeat all operations with another brush.
- Put on the casing on the angle grinder and fix it with a self-tapping screw.
Often there is another way to attach the brushes. In this case, the sequence of actions will be as follows:
- Remove the casing by first unscrewing the self-tapping screw.
- Release the brush from the clamping belt spring by tucking the last with a screwdriver.
- Remove the brush from the guide block by tinkering it with a screwdriver.
- Remove the brush contact from the connector. Also with a screwdriver.
- Connect the contact of the new graphite rod to the connector, insert the brush into the guide block and press down with the spring.
- Repeat all operations with the second brush, close the housing with a casing and screw it with a self-tapping screw.
These are the two most common ways to replace graphite contacts. Although other grinder design options are not ruled out.
angle grinder with rear handle
An angle grinder with a rear handle allows you to get to the brushes in a slightly different, simpler way:
- Near the handle, you need to find a small repair window, covered with a plastic plate, which is fixed with a self-tapping screw.
- It is necessary to unscrew the screw, pry a plastic plate into the groove with a screwdriver, remove it from the housing, opening the repair window.
- The following steps to replace the brushes are the same as for low-power grinders: release the tape spring (1), release the plug (2), remove the brush from the guide block by the wire.
- Then insert a new brush, connect the plugs, fix the graphite rod with a tape spring, close the repair window with a plastic plate and screw on the self-tapping screw.
- Repeat all actions with the second brush located on the opposite side of the case.
It is possible that there may be other ways to replace graphite brushes, due to the design features of grinders.
Structurally, the angle grinder is different from each other, so the brush replacement method may differ slightly from the basic methods described above. But the general features are still visible:
- The brushes are located next to the rear handle or to the part of the body that is designed to hold the tool.
- The most common designs of graphite brushes: with and without a spring.
The first type of design involves a simplified method of replacement, because it has a wire, a contact plate, and a compression spring.
Springless brushes require a slightly more time-consuming replacement process, because the fixing spring is attached to the body and it is more rigid, and the wire is attached in a separate place with a plug.