Abstract: Towed vehicle braking systems which are flexible enough for use by rental agencies and provide good safety features use a compressor (15) to drive a fluid actuator (12) with a piston (11). The piston is attached to the towed vehicle's brake actuator (30), e.g., a brake pedal or hand grip. The free standing braking system case is positioned within the towed vehicle by a positioning mechanism (32), e.g., a scissors jack. The braking system is actuated by one or more of (a) a towed vehicle velocity decrease sensor (46 and 47) (46 and 52); (b) a separation of the towed vehicle and the towing vehicle sensor (63 and 64) and (c) coded signals from a transmitter (66), e.g., radio frequency, used by the driver to control the braking system of the towed vehicle when received by a towed vehicle receiver (67) and used to actuate the towed vehicle braking system.