I own a 2015 Ford F150 Platinum with FX4 Package. My front driver brake was seizing at times causing noise. The front brakes have been replaced with rotors, calipers, and brake lines to caliper replaced and fluid flushed. Noise is still there and when I switched to 4X4 Auto the noise disappeared. What is going on? Next step is to change the front differential. Has anyone experienced this same problem?

 

Welcome. Not sure if this exists on the 15, but earlier mistakes on earlier models folks would reverse the pads. If you pad set has one pad with ears and another without, the ears pad goes on the inside.

Newer sets no longer have the 2 different pads.

 

Thanks for your comment....safe travels!

 

Describe the noise.

 

Slight roar as if the brakes/calipers are not releasing

 

I have replaced the wheel bearing on the passenger front, the rotor, caliper, pads and brake hose that had a kink in it. The noise is still there when braking. Front end transfer case service is next.

 

Welcome.

 

I think I now the solution to my noise problem. The "Vacuum Hub Actuator" on the FX4 system may experience failure due to a malfunctioning solenoid leaking vacuum reservoir. Causing the clicking/ratcheting sound leaking vacuum line that cause random wheel hub engagement and grinding noises.
Has anyone else experienced this problem/situation?

 

It wouldn't be too unusual for a diff to be bad in your model year unfortunately.

Mine made a noise, generally when slowing down at/near parking lot speeds. No noise at normal driving speeds but was very noticeable in a parking lot. It was not constant, but it was fairly constant in cooler weather. Probably not a single peep in summer months here in CA where I live. Spring and fall was intermittent. During those periods I did hear the noises, 4a would shush the noise about 40% of the time.

Transfer case is pretty easy to service, but transfer case isn't in motion while in 2wd. I don't know what the front end transfer case is that you're talking about though. If you do tackle the transfer case service, make sure to loosen the fill plug first so you know it can be removed to fill it. You will probably need to get the little pump thingy for the quart bottle.
If the noise is only apparent while braking, it should not be a diff or transfer case though.

I'd take the suggestion from earlier in the thread to check the pad installation. I think the pad will touch the wheel the entire time though, not just while braking. Never hurts to double check your work though.

I don't know what kind of roar a caliper makes so I can't help with your sound description, but a diff can/does howl/goan. An IWE Rattles.


After readings your first post and your answer to me, I am leaning away from it being a brake issue. Like I said, I don't know what noise a stuck caliper makes, therefore I don't know if I can get on board that the caliper problem you found is the root cause of your noise. I think the noise led you to an inspection which helped you identify a brake problem.
The point I'm making is you said you had a noisy caliper and the noise exists after repair. Therefore, I think unrelated.

 

Okay, now you are on to something.
That rattling noise you're describing is what I was hoping you would answer when I asked you to describe the noise.

If you are capable of troubleshooting, don't throw parts at it. 99.854% of the time the solenoid is fine. It could be a check valve but 75% of the check valves being replaced did not solve the problem. The check valve in my 2016 was still working as it should in late 2022 when I traded it.
The vacuum reservoir fails even less than the solenoid.
Could be a leaking or clogged vacuum line to the wheel. They can clog sometimes reducing vacuum supply to the wheel, therefore causing a problem with disengagement.

The system functionality is defaulted to a locked hub. Vacuum will disengage the hub by 'pulling' the teeth away from the hub. With insufficient vacuum, the hub never fully unlocks.
My first suggestion to anybody and everybody troubleshooting is to simply disconnect the electrical connection from the solenoid and just drive it for a few days. The hubs will be fully locked 100% of the time. If the IWE is in fact the problem, the noise should never occur when the electrical is disconnected. It is harmless. Be careful with the connection, it's pretty snug -take your time so as not to break the locking clip.