Odd Brake Shoe Failure. Any Ideas?

Old-Biscuit wrote:
This only occurred on the secondary shoes (rearward ones) and NOT on smaller primary shoes??

Primary shoes get most of the heat due to being first to make contact and that contact force has to increase to activate rear shoe engagement


Were dust caps missing on bottom of drum?
Does your son do much dirt road/off road driving?
Seen similar scoring from dirt/grit but it was on ALL brake shoes.

Otherwise.....HEAT causes most cracking.

DId you have to back off adjuster a LOT to get drum off?

Yes, just the secondary shoes. The others were in great shape.
Dust plugs were in place.
This is not "scoring". It's king of hard to see in the pics, but the cracks appear to go all the way to the base metal of the shoe surface.
And he does drive down a dirt road from time to time, but most travel is on paved surfaces.
I did not have to back of the adjuster at all to get the drums off. The brakes were snug, but not too tight.