From a speed of 20 miles per hour
 
Stopping distance in feet
Deceleration in feet per second per second
Brakes on all wheels   
30
14
Brakes not on all four wheels   
40
10.7
 
(j)   All brakes shall be maintained in good working order and shall be so adjusted as to operate as equally as practicable with respect to the wheels on opposite sides of the vehicle.  (ORC 4513.20)