View Full Version : blue vacume line?

December 21st, 2009, 20:06
90 4.0 auto, passenger side under the stock coolant return, there are several vacume lines blue, green, red ect.. the blue comes outta a 3 way set and hits a black round ???, then bo line outta that unit, ive seen others connected, what does this line do and go???

Wayne Sihler
December 21st, 2009, 20:12
It goes to the shift lever for the front axle disconnect,from the vacuum switch on the Transfer case.


December 21st, 2009, 20:21
4x4 seems to work well, i will look it up in the morn, should i be concerned? what/where should i be looking for bud?

Matthew Currie
December 21st, 2009, 21:00
One of those lines, I think it's the blue but it's been many years, should dead end to atmosphere through a filter. When you switch from one state to the other, the switch opens the unused side of the diaphragm to atmosphere. So don't change anything unless you have two open lines there.

December 22nd, 2009, 07:46
ill crawl under her and chech all if i see nothing than i'll do nothing! thanks