When I cycle the key the vacuum pump does not shut off even after starting the engine. Also noticed that the Max A/C setting was very slow to go to recirculate mode a couple of weeks ago. Is there a leak or did the pump take a dump? Any body have this prob? '04 6.0 39K miles

 

If the pump is constantly running and your A/C is slow to switch from defrost to vents, then you have a vacuum leak somewhere.

 

you have a leak somewhere. do you have a 4wd?

 

Yep, 4x4. How do I find the leak?

 

I found the leak. The line to the heater hose valve was disconnected. Thanks for the feedback !

 

great job. glad it was a easy fix.

 

Aren't they all that easy