I been having a major problem with MTH’s rail wipers. I been removing them and adding Aristo’s wheel brushes.
I started to work on my MTH Challenger. I noticed a lot of sparking from the rail wipers. I found wheel brushes on two sets of drivers on both trucks. When I checked the brushes with a"OHM" meter. I seen the brushes were not contacting the wheels.
I removed the brush holder and brushes. I found the brushes were to tight of fit in the brush mounts. I had to reduce the diameter of the carbon brush. I also had to shim the spring. The brush holder is made so I could not remove the spring. I wanted to replace the spring with one from a ball point pen.