Change the carbon brushes in a drill

Carbon brushes or coals in the drilling machine are designed for long lifetimes and usually over 50,000 operating hours. In the life of a normally used drill, changing is usually only after ten or more years. Noticeable is the wear on a decrease in the drilling force despite unchanged procedure.

Appearance and shape

If the power of a drilling machine decreases after a few years, this may be due to the carbon brushes, also referred to as coals. Two identical coals are mounted on the engine of a drill. The black-gray blocks are each firmly connected to a spiral spring. New coals also consist of a black and rectangular small block placed on a spring.

The exact appearance may vary slightly depending on the manufacturer. The guides of the coals are gold or copper colored. So that the springs do not pop out, different types of locking are mounted. They declare themselves at view. Depending on the type, a screwdriver or pliers are required for removal.

How to change the coals in your drill

  • New coal set
  • screwdriver
  • Pointed pliers or precision mechanics pliers

1. Check condition

When you open the drill housing, the coals become visible. They are located on the side of the motor facing away from the drill head and should still have a minimum thickness of five millimeters. The change in favor of drilling performance is worth starting at about eight millimeters residual strength.

2. Solve

The coil springs below the coals are secured in some models by inserted metal flakes or guide grooves from jumping out. These must be released by pulling or pressing. The coal itself is pulled out of the guide channel with the pliers.

3. Insert

The new coal is used with a pair of pliers in the empty channel as the predecessor has sat.

4. Clamping and locking

If there is no catch, a clicking sound signals the firm click. With locking the noise occurs only after reassembly.

5. Testing

Close the machine housing and allow your drill to idle for about five minutes without drilling. After that, the material has gotten used to each other.

Tips & Tricks

Buy a matching replacement set of original carbon with a new drill. After many years, you can avoid the sometimes time-consuming search for the right replacement accessories for repairs.

Video Board: ► How To - Replace Worn Power Drill Brushes ◄