Allmand — D.C. Motors (Wound Field) Service
Maintenance · D.C. motor (wound field)
From a Allmand service manual covering: M-250 Series, M-258, M-259, M-301, M-303, M-304, M-310, M-311, M-313, M-314, M-319, M-326…. Check it applies to your exact model before use.
Procedure
- Remove head assembly from motor.
- Check sleeve bearing in head assembly for wear.
- Place a few drops of oil on felt liner in head assembly.
- Check brush set for wear and replace if necessary.
- Blow dirt and dust out of motor housing and check for shorts, burnt wires, or open circuits in the field coil assembly.
- Check armature and commutator for shorts or open circuits.
- Check ball bearing on motor shaft; growling can be caused by bad bearings.
- Check for excessive end play of armature and add thrust washers as required.
- All D.C. motors turn counterclockwise when viewed from drive end.
- If motor fails to turn the pump, check the pump by turning the drive shaft by hand.
Source: Allmand service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.