Collector
1. Check the anchor surface for damage and wear. If there is damage or wear, replace the anchor.
2. Check the collector surface (1). If carbon deposits or dirt are found, sand it with sandpaper (No. 500 or No. 600) (2).
3. Measure the collector diameter. Nominal value: 33.0 mm. Limit wear: 32.4 mm. If the diameter is below the limit, replace the anchor.
4. Measure the radial runout of the manifold (3). Nominal value: 0.02 mm. Limit wear: 0.05 mm. If necessary, clean the spaces between the collector lamellas from carbon deposits. If the measured value is less than the limit, replace the armature.
5. Check the amount of protrusion (4) collector lamellas. Nominal value: 0.5 mm. Limit value: 0.2 mm.
Note: clear gaps (6) between the collector lamellas. The grooves between the lamellas must not protrude (5) or have a V-shape (7).
6. Check the integrity of the circuit between the collector lamellas. If there is an open between any of the collector blades, replace the anchor.
7. Using an ohmmeter, check the insulation between the collector (8) and armature winding (9), as well as between the collector (8) and shaft (10). If the circuit is shorted, replace the armature.
Brushes and brush holder
Attention: Damaged or oily brushes must be replaced.
8. Measure the protrusion of the brushes. If the length of the protruding part of the brush is beyond the wear line, replace the brush.
Note: when installing new brushes, lap them against the commutator. To do this, lay sandpaper (No. 500 or No. 600) abrasive outward between the commutator and brushes. Gently rotate the armature so that the brushes take the form of a commutator.
9. Check the insulation between the positive (11) and negative (12) poles and brush holder. If the insulation is broken, replace the brush holder.
Note: so that the brushes do not fall out during the test, fix them with a suitable sleeve (13).
Freewheel
10. Holding the clutch housing, turn the drive gear: the gear should rotate evenly in one direction. The gear must not rotate in both directions. If the gear rotates in both directions, replace the freewheel.
11. Check for excessive wear and damage to gear teeth.