my 79 300d euro has two problems, not sure if they are related. 1st it is not turning off. 2nd the brakes are acting odd. sometimes the pedal is rock hard, sometimes it is so soft it goes to the floor with almost no braking power. to make this a little more complicated,the longer you drive the tighter the brakes get. after a 30 min. trip simply pushing in the clutch causes the car to slow rapidly! when to shut the engine off you car hear the brakes releasing pressure. do you think it is the brake booster or vacuum pump or both?

You are having problem with your vacuum system. Diagnose it and replace the needed parts. Check the valve and the vacuum pump first.

when i take the hose from the vac. pump off of the brake booster i feel no suction on my hand is this normal? could the pump be working sometimes, this might explain the inconsistent braking?