So I just noticed that turning the wheel almost to lock or to lock and slightly letting off I get a hissing noise or the sound of a loss pressure air leak from the steering wheel. What is in the steering wheel that could be causing this? Haven't had time to take things apart and look but wanted to see if anyone else experienced this.

FYI truck does have adaptive steering if that matters.

 

That's probably the sound of the steering pump pushing hydraulic fluid when there's no where to go. You should let the steering wheel back off a degree or two when you get to the end of rotation.

 

The sound is in the cab at the steering wheel. No noise outside the truck at all. I know the sound your referring to and that's not what I'm experiencing.

 

I've noticed the same thing and my wife commented it almost sounds like the sound is being amplified in the cab, like through the radio. A hissing, gurgling sound like the hydraulics are right in the steering column. I thought I was just nuts.

 

Pretty sure it's the Adaptive Steering. Mine does the same. My guess is it's the mechanism hitting it's limits. Kind of the equivalent of the noise made under the hood, but all the adaptive steering technology is behind the wheel.

 

I don't have adaptive steering, and still have the same noise. Other threads in the forum seem to say it's common/normal.

 

Same here.

 

No adaptive steering and I also have that fluid noise at my steering wheel. I thought maybe it was from the steering pump. I did notice that part of Ford's 10,000 mile check up is listening for steering noise.

 

I also dont have adaptive steering and have the exact same noise as well when turning all the way. Been meaning to post it on here to see if anyone else knows what it is, but I keep forgetting.

 

This is awesome. Either I'm not nuts, or a whole bunch of us really are. No adaptive steering here either. I am also familiar with the maxed out steering wheel rotation sound on normal power steering. That sound comes from the pump.

Not necessarily considering it a flaw, just notification to back of on the rotation a bit.

 

I have it also and don't have adaptive steering. I couldn't remember if it was there from day one or not but it has been like that for a while now. I go in for my 10K maintenance this week and will mention it to the service advisor.

 

Same here. It's not hitting the stops either.
I'll keep my ears tuned and get it looked at soon too.

 

My brand new truck has it too... My Duramax made a similar noise, though it had hydroboost, and my 72 Buick GS with power steering did it. I don't think it is anything to worry about and sounds pretty common (no pun intended). It sounds like the power steering is at it's limits and the pump is straining, causing what sounds like cavitation or a hydraulic vibration.

It​​​ might sound like it is coming through the steering wheel due to structural acoustics sound conduction through the hard metal steering train. It's kinda of like when you wear ear bud headphones and the sound from the cables hitting things gets conducted and sounds really loud in your ears. Any vibration in the steering train could very well be transferred through the steering shaft into the cab.

To demonstrate how powerful this phenomenon is: I had to have the hydroboost hard and soft hoses on my dmax changed out due to a leak. The shop did a crappy job and one of the metal tube portions was every so slightly bent, which made it kiss the side of the hydro boost pump. This caused a terrible whining sound (really just the normal whine of the pump) to get amplified and transmitted through the whole steering system and right into the cab which you could hear and almost "feel" through the steering wheel. Granted, this was a different sound than what we are hearing on the Ford, it just goes to show that sometimes structural acoustics can be a pain in the ****.

 

Its just sound transmission from the pump, think of the steering shaft as kind of a tuning fork.

 

But that's the strange part, the pump is not making a noise outside my truck, i stood outside with my head against the fender listening while i had someone turn the wheel. It's only inside the cab right around the center of the wheel.

Does anyone have a diagram breaking down the parts for the steering wheel?