While tracking down a hvac vacuum leak ( bad check valve ) as I was vacuum testing certain areas of the vacuum system to check for leaks. I isolated the vacuum line to the cruise control line and applied vacuum to the line but it did not hold. Does anyone know if it should or only when engaged? Also the 4wd CAD does not hold vacuum when tested seperately. I know I got more than one vacuum leak around the transfer case area where the plastic lines go into hard lines. More concerned about Cruise control cause its inop. Checked fuse, fuse is ok.

 

The line runs to the cruise servo, which is under the battery..... the battery drips rude, nasty stuff down there, and it corrodes everything. Need to pull the battery, and, unfortunately, the battery tray, and see what things look like.

For the 4x4, there are steel lines that long along the frame that like to rust out.... may wanna have a look at them too.

 

I will pull the battery/ tray out and have a look. Is there a diaphram in there that is suppose to hold vacuum even is not activated?

 

I don't think it should just vent like that. The PCM controls a couple valves to maintain proper speed..... My guess is either the line broke, or, the diaphragm got holed.

 

And I bet its non-serviceable and the entire assembly would have to be replaced.

 

Are you sure you have to remove the battery tray?? If it's the same 3 bolts as it is on my 94, you don't have to. Hell, I got mine servo out without even taking the battery out. I removed the Christmas trees that hold in the rubber flap between the radiator and frame, and had a peek in, and I was able to get to the bolts with a small extension and a swivel piece. A little tight but it's possible.

 

my cruise control stopped working and I found the vacuum lines at the back passenger side of the motor to be very brittle and have some cracks.. I got some line and fittings from O'reilly's and everything now works as it should.. prior to this I had my cruise stop working.. I believe it was due to a badly blown plenum gasket on my 360

 

Yes, it should hold the vacuum.