I have a '96 3/4 ton 4x4 and my crankcase blowby tube is starting to blow out a noticeably greater amount of oil. My 4x4 takes alot longer to engage and my cruise stopped working a few months back. All of these symptoms lead me to believe that i have a vacuum leak somewhere. where is the best place to test the vacuum and does anyone have any tips for me. Any insight would be greatly appreciated.

 

Check the vacuum line that goes to the cruise control module,, its under the drivers side battery, they tend to rot off alot in that location due to the acid from the battery.

 

Lines also tend to get knocked off around the fuel filter in a change.
Line on the firewall above turbo melted.

 

I tested my vacuum system using a mity-vac hand vacuum pump. I disconnected the rubber vacuum lines one at a time until I found the component that was leaking. I had a broken line at the CC actuator when I first bought the truck and just last weekend the diaphram on the CAD failed. After I replaced the CAD actuator I checked the entire system using the vacuum pump to draw vacuum through an unused port on the hard plastic line on the firewall. My vacuum system is leak free.

 

are these vac lines available from dodge to replace these aging, cracking plastic lines?

 

The line to the c/c is available by part# the rest are hit and miss.You can buy the line by the foot from a good parts supplier