The vacuum pump on the engine in my '86 300SDL has two ports; one is for thebrake booster, the other is a smaller port that appears to handle the emission control system. Does the pump supply vacuum to both of these ports? I have vacuum on the brake booster port, but not on the smaller port. Is this a normal condition?
No, I don't think so. (Assuming you disconnected all the potentially leaky stuff and just hooked up a vacuum meter.) -- Jim
