I have a mercedes 300D Iam getting no vacuum from the pump It is a 1 975 I run the car but no draw?

Answer 1

Are you sure there's no draw? If you are testing anywhere but right at the pump, it's possible that there is a leak elsewhere in the system. I usually begin at the pump itself. I there's vacuum there, I check each leg of the first branch, and proceed systematically through the vacuum system.

If the pump really isn't drawing, it will need to be rebuilt immediately. The reason you need to fix this quickly is because a ruptured pump diaphagm will allow oil to migrate into your vacuum system. The various vacuum motors, check valves and the brake servo aren't designed for oil contact, so the repair can become very expensive. If the oil pollution is very extensive, it's sometimes cheaper to scrap the car than fix it.