Replacing washing machine motor brushes

Purpose of motor brushes

The centre of the motor (the armature) rotates but needs an electrical contact in order to do so. Wires can't be used as they would wrap around themselves and snap, so instead the electrical contact with the armature is made via carbon brushes as carbon conducts electricity. However, there is always friction between the carbon brush and the commutator (the copper segments in the armature) and this slowly wears down the brush with usage. The brushes are spring loaded either directly into the motor or, more commonly, in their own holders so that as the brush wears down contact is maintained with the commutator.

Faults and fault finding

The main symptom of motor brushes failure is that the machine will fill and empty as normal on a wash cycle but the drum doesn't turn on the wash or spin sequences. Sometimes, after the machine has cooled down and is empty, the drum will turn but there is often excessive sparking coming from the motor. This occurs because the motor brush has worn right down and is no longer providing the electrical contact to the motor.

The part of the brush that contacts the commutator is normally of smooth and shiny appearance. When worn out, the surface looks scorched brown and dull from the sparking caused as contact was being lost.

Replacing

Most motor brush changes are relatively easy, the main problem usually being gaining access to the motor. The easiest motor brush change is the 1600474 kit fitted to many Hotpoint/Creda machines as the motor is accessible by removing the machine's lid and the brushes simply click into place.

For most other machines, however, the procedure is a little more involved:

1. Locate the motor in your machine (most are at the bottom);
2. Work out the best way to access it - does the back panel remove or can you get to it from underneath?
3. Can you remove the brushes with the motor in place? Brushes are often held in with 2 small bolts or screws and if you can undo these then you will manage to change the brushes with the motor in situ;
4. If you can't then you'll have to remove the motor. Although this sounds like a major job, it's normally very easy on most machines as they are only held in place with 2 or 3 bolts;
5. Remove the old brushes and replace with the new ones;
6. IMPORTANT: some brushes are held in their holders with a retaining clip for when they are in transit. If you fit the brushes without releasing the clip the brush won't make contact with the motor and won't work. The carbon should extend 1 to 2 inches (depending on type) from its holder and will retract on fitting.

Difficulty

Easy to medium. The actual motor brush change is very simple but sometimes getting access to the motor can be awkward.