Chrysler played fast and loose with the truth about their hydraulic brakes. I have ads that say " like every Chrysler ever made this 1935 Plymouth has hydraulic brakes". Wrong! In 1924,the 1st year of Chrylser, they had split brakes with mechanical on the rear and hydraulics on the front. There is some indication the very first Chrysler 4s had mechanicals all around. Whether any of those got out is not known. But like Gary 30U says they still had rear mechanicals in 1927. External contracting at that. But by 1928 all Chrysler products had hydraulics all around with a mechanical band brake on the rear of the transmission for a parking/emergency brake. This setup would not change for 20 some years or until the parking brake went to an under dash pull chromed 'T' or 'L' and then to a pedal.