The RV brakes are designed to work with your tow vehicle brakes. To maintain proper braking performance, both the RV and tow vehicle brakes must be used together. Seperate use of the braking systems will cause accelerated wear and damage. When your RV is new, it is impossible to adjust the brake shoes precisley. It takes approximately 1,000 miles and/or 50 medium to heavy stops to "burnish" fit or "seat" the shoes to the brake drum. After the intial break-in period, you brake shoes must be adjusted accurately for best performance and increased durability.