Lionel 726 Berkshire

Good Day, Forum,

Question re. the Lionel '46 - '49 726 Berk brushes.  Can the carbon brushes be replaced by unscrewing the 2 brush housings located on the rear of the motor?  The 2 housings have slots which suggest they can be unscrewed using a flat blade screw driver.  I tried to gently unscrew one, but the resistance suggests that maybe they were not meant to be unscrewed.

Thank you. Urbie

On the 1946 Berk, the one with the screw driver slots, the brush tubes can be unscrewed from the rear.  On the 1947 to 1949 Berks, without the screw driver slots, can not be unscrewed.  These brush tubes are crimped in place.

Thanks, David, for the reply.  
Being able to access the brushes by unscrewing the brush tubes on the 1946 Berk is a plus.  Unfortunate, Lionel did not continue this feature in subsequent years.
My 1946 Berk is my favorite steam engine for many reasons.  Thanks again for your help. Urbie