Need advice how to inspect brush length, 50-year-old Black and Decker drill.

[FredB]

My wife bought this drill new about 50 years ago.  It's been a fine tool, plenty of torque, reversible, with a half inch Jacobs chuck.  The model number is worn off the label.  Before continuing to use it, I opened the case to inspect the brushes.  I'm not familiar with this style of brush holder and don't want to break something.  If you have experience with this style of brush holder, please explain how to access the brush.  That brass color metal on top of the brush holder is stamped "AMP."  I suspect that part is made by the AMP electrical connector company.

Thanks for reading.

Fred

[wingless]

Welcome to the forum.

 

Assumption is the tool stopped working versus nothing better to do than inspect the brushes?

 

The brush will have the exposed brass contact / connector, shown in the images, w/ the wired electrical connections, also shown.

 

There will be hidden internal electrical connections, usually made w/ bare braided wire, bonded to the backside of a block-shaped brush, w/ the business end having a curved shape, corresponding to the motor commutator.

 

There is also a hidden internal spring, that applies pressure to push the brush against the commutator.

 

Properly cleaning the commutator during inspection and / or replacement using an old-style pencil eraser is something I usually perform, to restore a great / shiny finish on the commutator.

[FredB]

Thanks for your reply.  The drill has been working fine.  I don't like to wait for brushes to wear excessively; that results in arcing.  Hoping that someone has experience with this design of brush holder and can answer my question: how to open the brush holder to examine the brush length.