How not to center sidepull brake calipers

[Sven]

I noticed this while changing my tire on my 72 Varsity . The first is obviously what the rear brake caliper is suppose to look like . The second what it did look like.

Another view. The lip on the pivot shaft spring retainer completely broken off.

After disassembling the caliper unit found that the radius bushings broke and the other cracked.

The culprit.

The culprit ONLY because a 10mm wrench was NOT used simultaneously with it to rotate the lock nut end of the pivot shaft.
You might ask how I know this.

Yep, I did it to another shaft. I heard this one break. I'm 99% sure I did the first one as well
I did not watch the Park Tool video as I should. I watch some other one where the host did not use the OBW-3 with the wrench.

Sometimes the best way to learn is to break something.

Here is the video if you would like to refresh your knowledge, skills and abilities

 

[AndyA]

Sven:
Bummer! Thanks for the schooling. It's always less painful to learn from others' mistakes. I never broke a pivot shaft, but that is probably because I had never seen a Park OBW-3 tool. Looks like it would be useful.