I only have two lines coming off the vacuum pump. One goes to the brake booster and the other to the air filter housing. The hoses are both swedge fitted to the pump, one black to the booster, one clear going to the filter housing. The clear one use to have quite a bit of air puffing out of it, that has now turned to a bluish puff of oily smelling air, and the volume has dropped. I would have to assume from that, the diaphragm has gone bad. the one going to the brake booster would be hard to get off as it is also swedge fitted to it's nipple. I guess it's possible to be sucking oil from the injection pump, but how could you tell for sure if either one could ingest oil into the vacuum system?