pbjc2008

It's a manual shift, all the tires are the same size.
The transmission engages but the front tires do not engage and the dash lights are not indicating that it's in 4 wheel drive.

pbjc2008

When I disconnect the vaccum line behind the battery I can hear a hissing sound.

ford4wd08

maybe your actuators at the hubs?? i would get a vaccum test then check the solenoid and then check the motor on the transfer case that engages 4x4

Fx-all-4-me

I just wandered my way back to this thread to say the same thing ^^^

drwillis

I have the same probelm with the Front wheels not engaging. What does a person need to check to check the vaccum lines? What should the reading on the gauge be? how do you test te IWE soleniod?

Any help would be appreciated

ford4wd08

the IWE is hard to test from what i know, i would just replace it with the redesgined model with a hood over it to keep the water out of it, thats why they go bad, for the vaccum lines i would just pay a shop to do it shouldnt cost a whole lot, the new IWE solenoid is under 30 dollars i believe

drwillis

Here's another question. The vaccum lines go to a round black unit, middle front of the front axle. Does this push/pull the axles to hubs, or what does it do? I haven't found any lines/wires to the hubs other than the anti-lock brakes. It also has a vent hose that goes up in the motor compartment. Is this the IWE solinoid?

I guess this is an education session.........1998 f150, 4x4 Lariat 136,000

ford4wd08

not familar with the 98 4x4 system maybe youll get more responses if you ask this in the 97-03 section.... just start a new thread

pbjc2008

if i disconnrct the vaccum line after i put it into 4 wheel drive it locks into 4 wheel drive put it wont do it just by sifting into 4 wheel drive

seniorFORDtech

check for a vaccum leak