Your new brakes and/or drums have shiny new surfaces that need to "mate" in order to grab and have stopping power under load. Right now as you pull away, you can squeeze your "manual brake" function on your controller and the trailer may lock and skid the tires, or may not stop you at all. There are several factors involved. Here's some tips to insure your brakes burn in evenly. 

• Set your controller "gain" (strength) setting to between 3 and 6, depending on your trailer's size, weight, and number of axles. (less for 2 brakes and 20 ft., more for 4 brakes and 30 ft.) 

• As soon as you safely can, get your rig up to speed between 30-50 mph. 

• Engage the manual brake lever on your controller to apply the brakes on the trailer only. (may be a button, lever, or squeezy thing)

• Apply trailer brakes for only a few seconds until you lose some speed. Release and allow to cool. 

• Get back up to speed and repeat process several times. (Speed prevents one brake or axle from getting a better grab than any of the other brakes.) 

• After several engagements, you should feel them grabbing evenly and consistently. Do it for 4 or 6 brakes, you may want to do more. 

• Now you can begin to think about how much brake you want for your situation. The "Gain" settings are completely up to you as a driver and your needs for your rig. Gain is not to be confused with "sync" which is a different function on some controllers to adjust the aggressiveness of the brake signal. Consider factors such as: your trailer, empty, driving on flat roads = low settings. Or: your trailer, fully loaded, driving through the mountains = high settings. Note: Your settings may change over time as components wear out. 

Reminder: The "Manual Brake," aka "the Override" or the "Oh S**t! Handle," is to help you on the road if you were to get into a "Sway condition." A trailer can begin oscillating side to side and throw the tow vehicle back and forth uncontrollably. Known to some as the "White Knuckle Ride," it has been known to overturn rigs. Applying brakes to the trailer will allow you to get your rig under control quickly and easier than if you hit your vehicle brakes, which could make it worse. A Sway condition can be initiated by many things such as a big truck wind blast, rough roads, or an evasive maneuver, but can get much worse quickly by things such as incorrect cargo loading, incorrect tongue weight, over loading, different air pressures, uneven braking, etc. This is why proper maintenance is so important. If you're on the road we recommend service once a year for bearings and brake inspection. 

Stay safe out there! 

Thanks from the folks at Portsmouth Trailer Supply!