leading and trailing drum brake shoes
ok there is always a mix up about leading and trailing [primary and secondary] brake shoes. I finally found a web page that had a pic and instructions on which is the leading [short] shoe. Many articles were misleading and just plain wrong! below is a pic of a left rear drum brake assembly, the leading shoe is the left one in this pic and is visibly shorter, this is the common drum brake setup.
http://www.aplsweb.com/Topics/Rear-Brake-Assembly.jpg
It is important also to check your brake shoes if you see any oil or grease leaking from the backing plates, I have an opinion that if you have any brake fluid loss can cause the rear axle bearing seal to weep and then evnetually bearing failure, or vice versa a bad bearing can cause brake cylinders to fail, as many time I have seen both problems. also the wedging action with drum brakes along with oil leaks can cause brake lockup.[ I heard of a guy that flipped his Buick at the drags because of that]. I usually look at the pix in my Motors manual to make sure whats right, I have found many brake shoes installed wrong.