Hello all,

I have a 1984 N/A 300D that has a vacuum leak somewhere i believe.

I have reduced the vacuum system to the single line going from the vacuum pump to the brake booster, with a gauge T'd into the line.

Upon starting the engine it takes approximately 20-30 seconds before the max vacuum is reached (about 22 in Hg) where it will remain while idling. revving the engine increases vacuum about 2-3 in Hg.

Upon stepping on the brake pedal, vacuum decreases slightly, and decreases more when the pedal is released (down to about 17) where it takes a few seconds to regain the vacuum. if i press the pedal multiple times quickly i eventually lose all vacuum and it becomes difficult to press the brake pedal.

are these normal vacuum levels/times? or am i looking at rebuilding the vacuum pump?

Thanks!