disconnect this hose:




connect tester. test.

 

It should have been something they tested. after not finding a leak any other place.

 

Well 2 weeks now since it has made the noise, they must have accidentally fixed it.

 

Wow. First let me say great info. Second, my head is swimming with reading all 25 pages.

If someone could help me real quick I'd appreciate it. My truck started making a noise that sounded like a vacuum leak. Starts under load at around 40 mph etc which led me to this thread.

I swapped out the solenoid behind the battery box, still have same noise. If I switch into 4wd when I hear the noise, it goes away.

So, what's next to swap out? Vacuum lines?? Whole new harness is $80.

Thanks for any advice.

Capt

 

very good information .I found my problem had a bad check valve and a bad actuator .there was more information here than in any of the books I have .thanks

 

check the actuators on the axles

 

I pulled the hoses off each side and put a vacuum tester on them. Drivers side held 24 psi. The passenger side would not hold any vacuum at all. So I ordered and replaced just the passenger side and I still have the rattling noise but now it just sounds a lot worse.

Could it be a check valve?

 

yes, it could be a check valve, or the line from the solenoid to the actuator.

 

I have a 2004 f150 with my driver side front axle stuck in 4w/drive. I do not have any vacuum going to the actuator so I replaced the solenoid and still nothing. What could be causing me not to have any vacuum to the actuator?

 

i would start by looking through this thread.

check if you have vacuum at the solenoid. if not, go upstream from there.

 

Took my o4 f150 lariat to the garage, replace both wheel bearings, both iwe's, all control arms, new tires, and $4000.00 later. I have just over 200000 mi. hopefully will be good for the duration of its life (except for the tires).

 

is that canadian??

 

I have a 07 f150 4x4 automatic with the 4wd shifter in the floor (less than 50k miles) making drive train noise. It is a high pitch squeak…squeak…squeak noise coming from the front or middle of the truck (hard to tell). The noise corresponds to the revolutions of the wheels/drive shafts, even does it in neutral. It is a little louder durring acceleration than deceleration. There is a sweet spot where you are neither accelerating nor decelerating in which it makes no noise. Each time I use 4wd it gets a little louder. You do not hear anything with it jacked up, spinning the wheel by hand. Not the brakes either. I made a mark on the drive shaft leading to the front diff, to see if was turning while in 2WD - it is not.

does this sound like a IWE issue? Any diagnostic suggestions would be appreciated.
Thanks WB

 

No, does not not sound like this problem.

What is does sound like though is U-joints, or a T-Case problem. I would check out or just replace your u-joints. It's cheap and easy..

 

Same problem! Noise, goes away in 4wd. I jacked the truck up and spun both front tires wile it was running and in 2wd. They both spin the shaft and front driveshaft. Does this mean no vaccume on both sides?