TC Brake shoe failure

[Frank Wissman]

Working on a friends TC that had a dragging brake, we found the RR trailing shoe had debonded with about 0.141" of lining left. And on the LR, there is a crack at pretty much the same place on that shoe. It seems to be near the notch in the shoe, but I can't wrap my head around the shoe flexing there. Has anyone seen this before and does anyone have a guess what caused this?

[jonwat]

11 hours ago, Frank Wissman said:

Has anyone seen this before and does anyone have a guess what caused this?

 

I had the material come away from the shoe once on a Rover but never seen a break like that. Defective manufacture maybe 

[NG5]

I tend to agree probably defective manufacture. Unless you know the history of the shoes and know them to be original quality, I wouldn't read too much into them breaking. There were some very poor quality shoes on sale at autojumbles and the like in the 1990's and early 2000's. If that was when they were last changed (and they don't look the newest).

The only other thing I can think of is if they were sticking on the back plate, the break is very near one of the dimples that the shoes slide on. If those dimples get worn to a ridge the shoes stick, but that usually leads to an unevenly worn shoe across it's width, not a break, and the linings look fairly evenly worn.

[Escape]

I've seen a few cracked linings when working on other classic cars. Never a clean break like that, but roughly in the same area. My theory is the brakes stuck on due to not being used and when forced free the lining cracked. We just replaced and all seemed fine.