RV Brake Parts Replacement
Here is the secret an old friend who is an RV mechanic shared with me:
The best source and method for RV brake repair is to go to Southwest Wheel as suggested by another member (or other trailer parts retailer), but don't buy magnets, shoes, springs, or other hardware. Buy complete new "loaded backing plates. " For approximately $45/per wheel you can buy a complete new loaded backing plate with new shoes, magnets, hardware, springs, etc. Most RV dealers will charge you approximately $25 to $30 for a new magnet alone. All you need to know is whether your trailer uses 10" or 12" brakes.
While you're at it, Southwest Wheel also stocks bearings and seals at a very reasonable price.