Spooled_Starion Posted October 21, 2011 Report Share Posted October 21, 2011 Ive noticed recently my vacuume is barely pushing -7hg. So to look for a leak I pulled the vacuume line off the cruise control and applied suction it held briefly before quickly bleeding off, I applied pressure to the lines and it instantly bled off at a weird black valve looking thing in front of the battery, behind headlight. This valve thing has a vacuume line going into it and a vacuume line coming out of it not attached to anything, any idea what this part is and where this vacuume line needs to be attached to? Why is it leaking pressure when I blow into the vacuume line? Link to comment Share on other sites More sharing options...
cooljs78 Posted October 21, 2011 Report Share Posted October 21, 2011 vacuum pump Link to comment Share on other sites More sharing options...
psu_Crash Posted October 21, 2011 Report Share Posted October 21, 2011 Remember your vacuum lines ultimately are connected to the intake manifold. This means that you should be able to blow into them. The cruise system has a vacuum pump that kicks in when the manifold vacuum isn't enough to operate the cruise and heater controls. In order for this to happen the valve would have to be energized to cut off the manifold source, which isn't going to happen with the car not under load. The better way to look for a leak is to disconnect a line from the intake and put a vac pump on that. On the underside of your hood there should be a vacuum diagram. Link to comment Share on other sites More sharing options...
Indiana Posted October 21, 2011 Report Share Posted October 21, 2011 If you put vacuum on that line it will take some time to draw down the actuators in your dash and if one is torn it will leak and you also have to draw down the storage tank. If you blow into that line yes it goes through that switch and out its vent and that's the pressure switch that turns on the vacuum pump behind the header panel. The vents in the dash and the cruise can't work without vacuum and under boost if they have to change their source is gone and there's also check valves so boost can't enter those systems to reverse what they are doing or even tear the diaphragms out and ruin them. Link to comment Share on other sites More sharing options...
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