In Spite of Danger (1935)

Bill Crane racecar driver has an accident while racing and finds himself unable to return to the fastpaced racetrack Looking for another occupation he meets a girl Sally Sullivan who runs a roadside lunchwagon and she helps him get a job as a truck driver They fall in love and get married He gets a contract to haul a load of dynamite and when coming down a steep mountain he finds his trucks brakes have been sabotaged just as were the brakes on his racecar