Legal Question in Business Law in Maryland

Re: Is there a law that specifies , that a used car dealer is responsible for g

There is no specific law regarding brakes as such. However, there are either express or implied warranties that should protect you if the vehicle was sold to you with defective brakes. An express warranty is something the dealer offers you as part of the deal. If you didn't get such a warranty in this case, the law provides that the item must essentially be in proper condition to be used as intended, or you can exercise contractual remedies, including possibly returning the vehicle. You should let an independent mechanic inspect the brakes and give you a repair estimate that you can then take to the dealer to show it that the brakes were defective when the vehicle was sold to you. If the dealer won't agree to fix the brakes or return your money, you can sue it.