Identification of signs of wear on the car generator brushes with the subsequent replacement of graphite elements

  • Dec 14, 2020

The brushes that are part of a car's alternator wear out over time. This necessitates their replacement. Work is not a complex operation, so these details are often forgotten. As soon as they decrease to less than the permissible size, they themselves remind of themselves. As a result, the generator stops generating electrical energy.

An example of a generator in Lada Vesta
An example of a generator in Lada Vesta

Wear symptoms

If the brushes have not been replaced after the vehicle has driven an average of 50,000 km, they may show signs of wear.

They are as follows:

  1. There is an independent shutdown of devices in the car.
  2. Headlights are weakened.
  3. There is a general voltage drop in the vehicle.
  4. Within a short time, the battery loses its electrical charge.

The presence of such signs indicates the need to check the brushes for the presence of workings in them. After disconnecting the negative terminal of the battery, the voltage regulator is being removed. This opens up access to the brushes. If their protruding part is less than 5 mm, then the parts must be replaced.

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Voltage regulator on the example of Lada Vesta

Preparatory stage

To replace the brushes, you first need to remove the generator.

This is done in the following sequence:

  1. Using a wrench, the bolt that holds the belt tension bracket is loosened.
  2. All fastening bolts are removed.
  3. The generator is removed.

There are brushes in the area of ​​the voltage regulator. They are held by springs pressing on them.

Removing the alternator can be tricky as the mounting bolts may rust. To eliminate it, you should use a solvent. After that, the dismantling of the old graphite rods and the installation of new parts begins.

This is how the generator brushes look on the example of Lada Vesta

Replacement steps

Removed brushes do not always need to be replaced. In some cases, it is enough for them to do maintenance.

This is done as follows:

  1. Using a soldering iron, the wires are soldered.
  2. The brushes are removed.
  3. The reliability of the spring mechanism is being inspected.
  4. The graphite rods are cleaned of dirt.

If the length of the brushes is sufficient, then they are installed in place. The work is carried out in the reverse order. First, the wires are soldered, and then the elements are returned to their original position.

With increased wear of the brushes, they are replaced with a new set.
Sometimes after finishing work and turning on the engine, a red light on the generator comes on, indicating a generator malfunction. This happens due to the loose pressing of the brushes. This phenomenon is temporary and soon the light goes out.

The same work can be done directly on the car. In this case, you do not need to remove the generator. For this, a voltage regulator is purchased along with brushes. After removing the old unit, a new one is installed in its place. In this case, you do not need to re-solder the wires. Such a replacement is only possible if there is sufficient free space for this.