[charade 1,0]

As 62/1 already said, the break-cylinders in the break-drums could be the reason for the leaking break liquid. Check the inside of the rims for tracks of break-fluid or you park the car on a dry concrete surface, build up pressure in the breaking system by stepping on the break pedal and if it leaks you should be able to localise the leak more easily by the tracks on the ground. If the break pedal sinks down while you step on it but there is no lose of breaking fluid the break booster might be the problem aswell.