If the rust spots are evenly spaced, you can use surface stitches to cover them. Good stitches might be Smyrna cross stitch, satin-stitch heart, queen stitch, satin stitch lozenges/triangles, palestrina knots, etc. If the spots are not evenly spaced, balance the design by adding extra stitches between the spots.
Fortunately, most states require drivers to equip their trailers with brakes and devices known as brake controllers. When a driver presses on the brake pedal in his truck, the brake controller lets the trailer's brake system know how much braking power is needed to stop the trailer.
Figure 5 - Brake lever adjustment points. Bicycle brakes allow for several adjustments that will change the level of braking power, speed of braking power, and cable tension. The easiest way to fine tune a bicycle brake is by adjusting the hollow bolt at the brake lever as shown in Figure 5.