Trailer Inspection Procedure Change

Effective 3/17/17

.01 Purpose

To eliminate the requirement for amperage draw measurement for the testing of electric brake application, to provide for a practical procedure for the testing of electric brake application during inspection, to lift the length restriction for trailer inspections at Class “A” and Class “M” Inspection Stations, and to allow trailer inspections to be performed outside of the main inspection area at those classes of inspection station.

Additionally, Class “T” Inspection Stations shall be allowed to inspect any trailer not equipped with air brakes, eliminating the restriction of 10,000 GVWR and under trailers.

.02 Policy

All Automotive Safety Enforcement Division (ASED) will be familiar with, and comply with the procedures and directives contained in this Standard Operating Procedure, and assure that applicable inspection station personnel are familiar with, and comply with the procedures and directives.

.03 Procedures

Electric Brake Application Inspection NOTE: All other regulations remain in effect as codified.

Amperage draw testing of electric brake application has been found to be ineffectual in determining the proper application of electric brake systems during inspection due to the variables in system voltages and resistances not allowing an accurate percentage of current draw to be measured.

Inspection Stations are authorized to remove the ammeter from the required tools and equipment maintained at their respective facilities.

Inspection mechanics shall inspect electric brakes for proper application using a tow vehicle to apply the trailer brakes in both forward and reverse and observe that all the brakes do apply and release properly. Alternatively the brake application may be tested as follows:

Lift the trailer until the tire(s) assembly may be rotated by hand;
Apply the trailer brakes using a tow vehicle, or an external power source;

Attempt to rotate the tire(s) assembly in both the forward and the reverse directions, and observe whether or not the electric brake applies and holds so long as rotational force is being applied to the assembly;

Reject any tire(s) assembly that will rotate by hand while power is being applied to the electric brake system.

Trailer Weight and Length Restrictions 

Class “A” and Class ”M” Inspection Stations which were previously limited to a maximum length of 20 feet for trailer inspections may now inspect any trailer which is not equipped with air brakes. Furthermore, trailers may be inspected outside of the inspection area, provided that they are performed on the premises of the inspection station.

Class “T” Inspection Stations which were previously limited to inspection of only 10,000 GVWR and under trailers, may now inspect any trailer which is not equipped with air brakes.