How to tell if my delco starter brushes are too worn

Redwolf · May 4, 2011

Starter has been hard to turn lately. I took it apart and shined up the brushes with emery cloth thinking it would help. All the brushes touch the aramture and look ok. Do they need to be a certain length?

Allan in NE · May 5, 2011

See that angle on the 'business end' of the brush?

Follow that angle in your mind's eye on back to the brush holder to make darned sure the holder isn't the one that's riding on the communtator.

If the starter is still 'trying' to turn, I'd be looking at the bushings or for shorted field windings, as the brushes aren't the culprit.

Allan

gene bender · May 5, 2011

No more than they cost replace them with new also rebush the starter both ends while its apart clean the commutator and slots also.

Owen Aaland · May 5, 2011

Generally they should be replaced before they are reduced to half of their original length. You want to make sure that they do not wear so much that the retaining screw head contacts the commutator bars. Without knowing what starter you are working on it is hard to give you a measurement. Gas engine starter brushes will probably be about 5/8" when new, diesels more likely about 3/4". I've got Delco replacement brushes here that range from 1/2" to a little over 7/8".

teddy52food · May 6, 2011

Usually the bushings are worn out long before the brushes.

How to tell if my delco starter brushes are too worn

Redwolf

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Allan in NE

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gene bender

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Owen Aaland

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teddy52food

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