Brushed Motor Maintenance

What?

Most electric motors have "brushes" that rub against another part called a commutator and slowly wear down. They eventually need replacement which is standard maintenance and usually pretty easy to do.

In this example, we replace the brushes on an MP 29924 pump that circulates fluid through a hydronic heating system.

• Philips-head Screwdriver
• 5/16" Wrench
• 3/8" Wrench
• 5/16" Socket
• Socket Spinner Handle
• 4" Socket Extension
• Small needle-nose pliers or flathead screwdriver

1. Remove the pump and get it on the bench.
2. Remove the two 3/8" nuts on the pump head.
3. Remove the two philips-head screws at the back of the pump.
4. Remove the back of the pump where the two screws came out.
5. Pull the housing off the pump while pushing the rubber gasket with wires off.
6. Each of the two wires is connected to a brush.
7. Many pumps use connectors for the wire to the brushes.
8. Slide the new brushes into the holes where the old brushes came out.
9. Re-assemble and re-install the pump following steps 1-5 in reverse order.