Hi there! I recently resolved my problem of knocking noises from my 85 4kq. I removed the Piston and it ran fine, but my question is; what does that thing do anyways? I know it connects to the brake booster, but doesn't the engine provide enough vacuum without the vacuum pump? Well the car runs fine now... yeah! Aloha! David '85 4KQ '89 Maserati 430