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Brakes - FAQ?

 Parts & Service

Brakes – How do I measure brake current or amperage?

7″ brakes draw about 2.5 amps per brake and all other brake magnets draw about 3 amps per brake. The total system amperage is calculated by multiplying this number by the number of brakes/magnets connected to the brake system. To measure the brake current the engine of the towing vehicle should be running. Disconnect the wire at each point that you wish to measure the current draw and put the ammeter in series with this line. Make sure your ammeter has sufficient capacity and note polarity to prevent damaging your ammeter.

 NOTE: If a resistor is used in the brake system, it must be set to zero or bypassed completely to obtain the maximum amperage reading. The amount of current draw will depend on what point you are measuring. If the ammeter is at the plug, you will get the total current draw from all magnets. If the ammeter is connected at one of the magnets, you will measure the current draw through that magnet only.

Brakes – How do I measure brake voltage?

System voltage is measured at the magnets by connecting a voltmeter to the magnet lead wires at any brake. This may be accomplished by using a pin probe inserted through the insulation of the wires dropping down from the chassis or by cutting the wires. Voltage in the system should begin at 0 volts and, as the controller bar is slowly actuated, should gradually increase to about 12 volts.

Brakes – How often should I adjust my brakes?

It is recommended that manual adjust brakes should be adjusted… 1) After the first 200 miles of operation when the brake shoes and drums have “seated” 2) At 3,000-mile intervals 3) Or as use or performance requires.

Brakes – My brake linings are cracked, do I have to replace them?

Usually, light cracking of the surface of a brake lining can be expected under normal use. This is not cause for replacement. However, if the lining is deeply cracked to the shoe surface or is missing chunks, your brake lining will require replacement.

Brakes – Which magnet wire is the positive, they are both the same color?

The magnet is not a polarized component. Use one wire to connect to power from the brake controller and use the other to attach to ground. It is recommended that a common ground runs from the trailer plug to the magnets. Do not ground each brake individually to the trailer frame or structure. Also note that the brakes should be wired in parallel, not in series. The wire color is used to identify the component since so many magnets physically look the same on the outside, however, they are different strengths for the different capacity brakes.

Brakes – Why can’t I lock and slide my electric brakes?

On an unloaded trailer, you may be able to lock up your brakes if your electric brake controller is supplying full amperage to the brakes. When loaded to capacity, you may not be able to lock up your brakes as electric brakes are designed to slow the trailer at a controlled rate, and not designed to lock up the wheels on a fully loaded trailer. Our brakes are designed to meet all applicable safety standards. All of our brakes will perform better after numerous burnish stops to seat the brake lining into the drums.

Brakes – Why do I have to adjust my brakes?

Brakes must be adjusted to compensate for the lining and drum wear that occurs during the use of the braking system. Some brakes require manual adjustment to move the lining closer to the drum. Refer to brake adjustment in the support material that came with your trailer.

Brakes – Why do my brakes and hubs get so hot?

Braking systems use friction to slow the vehicle and the energy used to slow the trailer is converted to heat. Our brakes are designed to operate up to extremely high temperatures during hard braking applications. This heat is noticeable on the hub and drums and is to be expected on a properly functioning brake. If a brake is malfunctioning and running excessively hot, this can be noticed by smoking brakes or the paint burning off the brake drum.