disco brakes

Hi I have a 1993 discovery and while parked up for a couple of months the brakes have stopped working, the pedal goes to the floor and the brakes hardly work, any ideas, the previous owner had some work done on the brakes last year and the brakes worked perfectly when I tried them last about a month ago. The car does not use any brake fluid.And also the engine smells very hot very quickly(temp gauge does not work) it does not use any water, is this normal????
thanks Ian

air in system through leak or seals in master cylinder,check rad hot all over core ,and check level by removing bung exspansion tank not good indicator unless bung out

air in system through leak ,or master cylinder seals is there a splash in res when pedal worked, check rad hot all over core to see if working ,check top hose hot to see thermostat opening ,remove rad bung and on engine if its got one to check level exspansion tank level not good indicator with bungs in