Repair - TM-5-4930-233-140314

TM 5-4930-233-14

TM 4930-14/1

AIR COMPRESSOR ASSEMBLY

5-12. STARTER - REPAIR - (Cont.)

Repair

WARNING

Clean all parts in a well ventilated area. Avoid inhaling solvent fumes and

prolonged exposure of the skin to cleaning solvent. Failure to do so can cause

severe injury or death. Do not use near flame or excessive heat. Flash point of

solvent is 100 to 138 (38 to 59 ).

(1)

Use a cloth dampened with dry cleaning solvent to wipe all dust, oil, and other foreign material from the

brush plates, end frames, and armature and field assemblies.

(2)

Use filtered compressed air to blow dust and dirt from the crevices of the armature and field windings.

(3)

Secure armature in a lathe with armature spinning, hold a sheet of No.

000 sandpaper against the

commutator until the copper is bright and smooth.

(4)

Examine field frame assembly for cracks or warping. Inspect armature shaft end for damage or wear.

Replace defective parts.

(5)

Examine clutch for broken or cracked teeth. Replace if damaged.

(6)

Examine field coils for worn, burned, and frayed insulation. Be certain connections between field coils are

secure. Repair connections if necessary.

(7)

Inspect springs for distortion or fatigue.

Examine brushes for damage or excessive wear.

Replace if

needed.

(8)

Check brushholder for shorts. Replace if shorted.

(9)

Test armature assembly for open coils and shorts to ground, or between coils.

(10) Check field coils for open circuits and shorts to ground, or between coils.

(11) If commutator is out-of-round in excess of 0.001 inch (0.0254 mm) turn down on lathe.

(12) Replace all parts indicating wear, cracks, or damage.

(13) Undercut mica insulation between the commutator bars to a depth of 1/32 of an inch (.7937 mm). When

undercutting mica, the cut should be square and free of burrs.

5-55