Since I am swapping around complete Dolphin systems for testing, it made it very
easy to reach down and pull out a water pump brush. Was I surprised. The brush
still had about 85% of it’s length left after over 10k miles were put on it. The
originals only lasted a total of 10500 miles! What an improvement! If you look
at my photo album there are pics, descriptions and part numbers of the brushes I
bought and mdified for my water pump. They were only around $15 or something
compared to the $75+ factory brushes.

I thought for sure I’d be replacing them again. Some day I’ll pull the motor out
to check the commutator for wear since these are obviously harder brushes. Rough
math shows they will last about 60-70k miles.