Bosch Power Tools GCM12SD manual Maintenance and Lubrication, Motor Brush Replacement, Drive Belt

BM 2610007877 04-10:BM 2610007877 04-10.qxp 4/26/10 8:13 AM Page 51

Maintenance and Lubrication

	Service
	preventive maintenance performed
! WARNING
	by unauthorized personnel may

result in misplacing of internal wires and components which could cause serious hazard. We recommend that all tool service be performed by a Bosch factory Service Center or Authorized Bosch Service Station.

Motor Brushes

The brushes and commutator in your tool have been engineered for many hours of dependable service. To maintain peak efficiency of the motor, we recommend every 2-6 months the brushes be examined. Only genuine Bosch replacement brushes specially designed for your tool should be used.

Motor Brush Replacement

To inspect or replace brushes:

1.Unplug the saw.

!WARNING The brush cap is spring-loaded by the brush assembly.

2.Remove the brush cap on the motor using a wide, flat-blade screwdriver.

3.Pull out the brush (see Figure 64). Repeat for the opposite side.

NOTE: If installing the existing brush or brushes, make sure the brush goes in the same way it came out. Otherwise, a break-in period will occur that will reduce motor performance and increase brush wear.

4.Inspect brushes for wear. On the wide, flat side of brush is a wear limit line. If the brush contact face is at or beyond (no line visible) the limit, replace brushes as a set.

5.Install new brush. The two tabs on the brush terminal go in the same hole the carbon part fits into.

6.Tighten the brush cap but do not overtighten.

Drive Belt

The drive belt is a long life component; however, after extensive use, it may require cleaning or replacement. Dust and debris may enter through the ventilation system and affect the performance of the belt. Periodically, the drive belt should be inspected for excessive wear. If the belt shows signs of drying out, cracking or tearing, it should be replaced. If the belt will not track properly or comes off the pulleys, it should be replaced. Belt replacement should only be performed by an authorized service center.

Cleaning / Inspecting Drive Belt:

1.Unplug the saw.

2.Remove the two belt cover screws using a #2 Phillips screwdriver.

Drive Belt

figure 65. Drive Belt

3.Clean area with a brush or compressed air.

4.Inspect the belt. If dried out, cracked or excessively loose, it may require service and/or replacement.

!WARNING To avoid possible injury, do not attempt to replace the drive belt

(replacement requires special tools). Take saw to an authorized Bosch service center.

5. Replace belt cover and two cover screws.

figure 64. Motor Brush

51.