I have a 04 f150 fx4. I had problem with my 4x4 not engaging. I had vacuum to the IWE. The passenger side IWE not locking in. I when ahead and replace both IWE. And found water on the passenger side IWE. I went and replace the vacuum control valve to. My question is does any bode knows when you turn of the car does the IWE hold the vacuum or they lose the vacuum my holds the vacuum for a few second and then you hear the vacuum control valve click and lose vacuum is this normal. And how can I remove any water left on the vacuum line.

 

I leave mine engaged while parked in the garage and don't hear any engagement sounds after the engine is started. After backing out and don't need 4x4 I hear it disengaging.

 

The default is to vent vacuum and be in 4x4. This allows the use of 4x4 in the event of a vacuum leak.

JMC

 

So if you're buzzing along and lose vacuum you get 4wd engagement? That's dumb. An electrical circuit would last longer.

 

No I don't lose vacuum when the truck is on. Is when I turn the truck off after a few second. Is that normal to lose the vacuum to the IWE.