You've just completed a brake overhaul and then discover fresh gear lube leaking down on the inside of one of your tires. You take the wheel and brake drum off and discover that the brand new oil seal is leaking like a sieve, and your new brake shoes are ruined. What went wrong?
Did you check or replace the oil seal and distance pieces? Usually, the answer is "No, what's a distance piece?" The distance piece is the circular sleeve directly adjacent to the brake shoe backing plate (item # 1223). Any compromise of this seal surface will ultimately result in leakage. There has been some misconception that the distance piece is an integral machining of the axle tube - which it is not. Actually, it is very easy to replace.
First, using a sharp chisel (don't forget to wear safety glasses), cut into the face of the distance piece. The metal is relatively soft and will usually fracture after several blows of the hammer. Be careful not to cut into the axle tube as you may leave a burr in the surface which makes reinstallation difficult. Clean the axle with some solvent and some fine emery cloth as needed.
Next, lightly coat the area where the distance piece will be located with grease or anti-seize lubricant. This will allow the new distance piece to be driven on easier and will make future replacements easier, too. Slide the distance piece onto the axle tube, making sure that it's not cocked to one side or the other.
It is imperative that the piece is driven back on as squarely as possible or it may fracture. Using a piece of 2" I.D. pipe approximately 12" long, drive the piece on until it's up against the backing plate. wipe off any excess anti-seize lubricant and then lubricate the distance piece with either a light smear of bearing grease or clan gear lube. Lightly lubricate the lip of the new inner seal after it has been installed in the hub and you are all set to start to reassemble.