# COMAR Title 11 — Department of Transportation

## Subtitle 14 — Motor Vehicle Administration — Vehicle Inspections

### Chapter 05 — Safety Standards for Trailers

#### Regulation .04 Brakes.

*COMAR 11.14.05.04*

Trailers and semitrailers to be registered up to 3,000 pounds GVWR are not required to be equipped with brakes.  However, if such a trailer or semitrailer is equipped with brakes, all brakes shall meet minimum standards. Trailers and semitrailers to be registered from 3,001 pounds GVWR to 10,000 pounds GVWR shall be equipped with brakes on all wheels of at least one axle. Trailers and semitrailers to be registered over 10,000 pounds GVWR shall have brakes on all wheels. At least one wheel and drum shall be removed from each axle equipped with drum brakes. On disc brakes only wheel assembly removal is necessary. On trailers and semitrailers with brakes on more than one axle, wheel assembly removal shall be on alternate sides. Always inspect a brake assembly which shows evidence of leaking fluid or grease.

A. Drums and Discs.

B. Brake Linings or Pads.

C. Mechanical Linkage.

D. Hydraulic System.

E. Air Brake Leakage. Before conducting these inspections, it may be desirable to install in the system an air gauge (0—150 psi) which has 5 or 10 psi increments, so that small changes in pressure can be more easily observed. Also, to eliminate the possibility of leakage being in the system of the towing vehicle, conduct air leakage tests on the uncoupled towing vehicle before inspecting the system of the trailer or semitrailer.

F. Vacuum System.

G. Actuator Reserve.

H. Electric Brakes. Electric brakes are generally used on small and occasionally on large commercial trailers and semitrailers.

I. Emergency Brake. Every trailer, semitrailer, and pole trailer equipped with air or vacuum actuated brakes and every trailer, semitrailer, and pole trailer with a registered gross weight in excess of 3,000 pounds, manufactured or assembled after June 1, 1970, shall be equipped with brakes of a character to be applied automatically and promptly and remain applied for at least 15 minutes on breakaway from the towing vehicle.