IWE vacuum supply explaination

[fordfreek]

Vacuum line on brakes needed to be replaced. About 300 miles in, it started doing it again, and will occasionally trip the Check Brake System code.

So your saying that the hard brake pedal in the morning was caused by a defective vacuum line? The one going to the booster? Do you know which one specifically? I haven't noticed mine doing it anymore, but I remot start mine almost always in the situation that I used to find the hard brake pedal.

 

[Bracamonte]

So your saying that the hard brake pedal in the morning was caused by a defective vacuum line? The one going to the booster? Do you know which one specifically? I haven't noticed mine doing it anymore, but I remot start mine almost always in the situation that I used to find the hard brake pedal.

I’m just guessing that could’ve been it. I remote start mine a lot as well since I live in the heat. Driver side vacuum line. Thought it was a solenoid issue as well.

 

[fordfreek]

So I had my appointment today. Needs both uca's and right front "strut" as they called it for a clunk in the front end.
As far as the intermittent IWE engagement; no problem found.
After they tried to blow it off with the same bulletin that says to disconnect and plug vacuum line to the solenoid for the IWE's. I had to call them out on it. So I guess I'll give it a go and try and diagnose it myself.

 

[copperloss]

Hi there, I've been having a somewhat similar problem myself with my 2014 F150 3.5L XLT, was perusing the forums and came across your issue. Realizing its been over six months since your last post, hopefully the following may be of use for you.

I found this problem on the F150forum.com that someone had two years ago, which turned out to be the pinion bearings in the front differential which had managed to walk themselves out 1 or 2 mm. It played out like IWE issues very closely. I shim kit for the pinion bearings apparently is the 'third way' fix. Here's the link:

IWE vs. Check Valve - Ford F150 Forum - Community of Ford Truck Fans

2015 - 2020 Ford F150 - IWE vs. Check Valve - I complained twice to the dealer about grinding in the front. First they said nothing wrong and next time they confirmed grinding and replaced a check valve Now the grinding is back, not always, just once in a while. Are these two separate issues? I...

www.f150forum.com

If you're still stumped, maybe that is your solution.

 

[FordTechOne]

Hi there, I've been having a somewhat similar problem myself with my 2014 F150 3.5L XLT, was perusing the forums and came across your issue. Realizing its been over six months since your last post, hopefully the following may be of use for you.

I found this problem on the F150forum.com that someone had two years ago, which turned out to be the pinion bearings in the front differential which had managed to walk themselves out 1 or 2 mm. It played out like IWE issues very closely. I shim kit for the pinion bearings apparently is the 'third way' fix. Here's the link:

IWE vs. Check Valve - Ford F150 Forum - Community of Ford Truck Fans

2015 - 2020 Ford F150 - IWE vs. Check Valve - I complained twice to the dealer about grinding in the front. First they said nothing wrong and next time they confirmed grinding and replaced a check valve Now the grinding is back, not always, just once in a while. Are these two separate issues? I...

www.f150forum.com

If you're still stumped, maybe that is your solution.

There is no TSB for that described issue because it doesn’t exist. Pinion bearings cannot walk out; if the pinion bearings were damaged to the point that preload was lost, then you will have a high pitched noise from the front end in addition to possible R&P damage. Shim will not correct damaged pinion bearings, they need to be replaced.