: Can you identify this rubber hose/vacuum line?. 1984 Cadi Commercial chassis.

09-21-11, 12:16 AM
Replaced my broken power antenna and came across an apparent vaccum line running from under the dash out the passenger side kickpanel grommett (along w/ the antenna wire) and up to the front of the A/C unit. It runs along the front of the A/C unit and has about a 1 foot length loose and I cannot see where is should connect up. It is about the size of a pencil, and has about a 3/32 inner passage. The car is hard to start, but runs/starts easily when warm. I'm getting about 10mpg which seems a bit low, and it hesitates to accelerate at times, and sometimes seems to dwindle going uphill. I know vacuum leaks cause issues and wonder if this could be a source? Thoughts anyone? Car is a 6.0 V8, carburated, NOT the 8-6-4.

Thanks in advance.

09-21-11, 10:30 AM
Only hoses I can think that come out the dash would be vacuum source for heater controls, condensation hose for AC and cruise control vacuum brake. Does the heat change to different vents when you want it to?

09-21-11, 05:02 PM
Well, there is no cruise control, and I can't imagine a AC drain going uphill, so I will check out how my vents are switching, where does the line hook in under the hood would be next question.


09-21-11, 08:56 PM
The line for the heater would connect to manifold vacuum, not necessarily connected to the intake manifold(maybe) but something that has the same amount of vacuum. Maybe in front of the drivers head below the dizzy, but I dont know exactly how the 368 routes vacuum. Cruise control not optioned in the car or has it been disconnected?

09-24-11, 12:56 PM
Cruise was apparenty not optioned.

09-25-11, 01:36 PM
My guess is the hose goes to the coolent valve on the hose that goes into the heater core..When it calls for coolant to flow threw the heater core the programer sends vacume to open or close the valve...
the hard start when cold and poor gas mileage sound like a bad temp. sensor...