2020 fordf-150 4X4 hubs

On 2020 ford f-150 3.3l the customers complaint was noise from the front wheels in 2wd. We found that the IWEs were partially engaged. We tested for leaks by connecting a vacuum pump and gauge to the vacuum line going to the IWE solenoid and no leaks and the IWEs fully disengaged. We tested the IWE solenoid with a scan tool and it functions. We found that the solenoid does not turn on on its own untill the truck has been driven for a half mile. Ford says this is normal but the customer says it just started. Does anybody have any experience with these hubs and that can tell me you thoughts. The tccm was also replaced with no change

I've found it's common for the one-way check valve in the vacuum hose assembly to fail and not retain vacuum in the system while driving down the road. You can sometimes catch the valve failing with a hand vacuum pump. It should seal in one direction.

The check valve is sold integral to a hose assembly. The orange part:



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