Brakes release when stopped on slope (Powerboost)

[Bikertrash]

First time it happened to me I thought the same thing. I looked behind me and the van was close but had not made contact.

I’m going to turn off auto hold and monitor to see if I can reproduce.

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[Oxford_Powerboost]

Now that I think of it. I recall one or maybe two instances where I was at a light and it felt like the driver behind me may have slightly bumper tapped me. Maybe a slight body shake, but don't think the tires moved. But when I looked in the mirror, a driver was clearly at least 6 feet back. Each time it confused me. I wasn't looking to see how fast their approach was and also not sure if the truck has some type of rear pre-collision anti whiplash function as no dash pop ups occurred. Not sure if this is similar to what any of you guys experienced.

I’d say that’s an accurate description. It has never been enough for me to lose trust in the brakes. Feels like something happens in the trans that adds pressure more than it does the brakes releasing themselves. Since I use auto hold and tend to brake lightly, I bet the additional pushing force from whatever is going on in the trans just overcomes the brakes. Then the truck sees the wheels move ever so slightly and clamps the brakes harder, knowing you don’t want movement on auto hold

 

[UGADawg96]

I don't use auto hold. Just adding that as a data point.

 

[Snakebitten]

I use auto-hold pretty often. With both the 2021 and now the 2022. I haven't experienced any glitch yet or I would lose confidence quickly in the whole package.

I have noticed more than one strategy while using the feature. While stopped behind another vehicle I will initiate the "set+" cruise control speed variable beyond the 15mph start value. Then as the light turns green and the vehicles in front of me start to move, I hit the resume button and the truck gracefully starts to follow the caravan at the appropriate ACC distance buffer. All without my feet playing a role.

I only mention this to point out that the truck has more than one approach to using software braking, depending on input from the driver. And that implies the potential complexity of the software and multiple modules in play. These trucks can be equipped with what appears to be absolutely brake by wire. So glitches will obviously be uncomfortable to experience.

 

[Ford Motor Company]

I often stop my truck on the down ramp of an underground parkade while I wait for the garage door to close behind me. The ramp incline is 11 degrees as measured by the truck. About 2 seconds after coming to a complete stop with my foot firmly pressing down on the brake peddle, the brakes let go and the truck rolls forward a few inches before the brakes reengage. I assume this has to do with the mechanical brakes taking over from the regenerative brakes, however, it is somewhat disconcerting. Has anyone else noticed this issue?

Hey there! I can look into your F150's break concerns on my end if you’d like. Will you send us a message with your VIN and dealership info?

 

[Severdog]

For you guys feeling the brake "creep," I think that it would be important to know whether the ICE is spinning at the time, or just on EV. I can't solve it, but someone will ask along the way and you'll need to know that data point. cheers

 

[thebigdu]

For you guys feeling the brake "creep," I think that it would be important to know whether the ICE is spinning at the time, or just on EV. I can't solve it, but someone will ask along the way and you'll need to know that data point. cheers

My "brake creep" with Auto-Hold engaged happened again this morning, and it felt like the truck moved a good two or three feet before reengaging. And I'm holding my foot far away from both pedals to ensure I'm not accidentally feathering the throttle or something. IIRC, the ICE has been off every time I've experienced this.

But I believe the OP has a much more serious problem if he's experiencing loss of brake power while actually holding the pedal firmly.

 

[Oxford_Powerboost]

For you guys feeling the brake "creep," I think that it would be important to know whether the ICE is spinning at the time, or just on EV. I can't solve it, but someone will ask along the way and you'll need to know that data point. cheers

Always in EV mode.

I paid more attention to it today. Seems like the electric motor applies No forward force as you come to a stop (unless you let up on the brake, indicating you want to creep). Once you stop, it seems like it spins the electric motor back up so as to mimic what a normal running engine with an automatic trans would do in drive. This could cause the creep

 

[Mhubbardva1]

Hello,

My name is Kyle and I am a Ford Technician. If I am reading this correctly the truck moves forward even when your foot is on the brake. The truck should not move anywhere when your foot is on the brake no matter which drive mode the vehicle is in. I ran a symptom based report through the Ford database and did not see any issues like the one you are having. I will keep an eye out if I come across anything like this.

I have a 2021 and it happens to me all the time.
I will be in heavy traffic, come to a top with my foot on the brake and the truck starts rolling forward. I quickly remove and reapply the brake with more force.

 

[Bettermoa]

I found this regarding the Powerboost brakes. It implies that our brake pedal is brake-by-wire, similar to our throttle. In other words, our pedal doesn't actually create brake fluid pressure, but rather sends a signal to the monitoring system what our pressure/travel of the brake pedal is and then the ABS system applies the actual hydraulic pressure.

Again, I'd get your truck looked at. So your gauge cluster doesn't show any warning lights when the truck lurches and then stops again? I wonder if your truck has codes stored as a result?

Found this about the brake system

https://thebrakereport.com/regenerative-braking-virtually-invisible-in-f-150-hybrid/

 

[AllFordTech]

I have a 2021 and it happens to me all the time.
I will be in heavy traffic, come to a top with my foot on the brake and the truck starts rolling forward. I quickly remove and reapply the brake with more force.

This is very interesting seeing as multiple people are having the same issue. I’m going to try and dig a little deep and see what I can find.

 

[Snakebitten]

Regardless of what's going on, these are the first F150's that have features that influence the way we use our hands & feet differently, which previously had become second nature and in our subconscious muscle memory.

I only say that from my own personal perspective and do not mean to imply anything beyond what I'm admitting myself. ??

It's a foreign experience the first time I was stopped and the engine was dead and the truck tried to roll forward with 0 rpms. I then realized that it's not dead. It's just electric and has the programming to behave exactly as it would if the engine were running. Fascinating, to be honest.

 

[thebigdu]

Regardless of what's going on, these are the first F150's that have features that influence the way we use our hands & feet differently, which previously had become second nature and in our subconscious muscle memory.

I only say that from my own personal perspective and do not mean to imply anything beyond what I'm admitting myself. ??

It's a foreign experience the first time I was stopped and the engine was dead and the truck tried to roll forward with 0 rpms. I then realized that it's not dead. It's just electric and has the programming to behave exactly as it would if the engine were running. Fascinating, to be honest.

There's some great engineering in these trucks no doubt, but brakes are brakes. It shouldn't move an inch whether they're applied by foot or electronically held.

 

[Snakebitten]

There's some great engineering in these trucks no doubt, but brakes are brakes. It shouldn't move an inch whether they're applied by foot or electronically held.

I agree.
I was just pointing out that for the first time in my 50+ years of driving, I've found myself sitting at a stop without my foot on the brake. It just scrambles my brain sometimes.
As well as when my dead silent truck accelerates when I let up on the brakes a bit.

It's hard to untrain my instincts

 

[thebigdu]

I agree.
I was just pointing out that for the first time in my 50+ years of driving, I've found myself sitting at a stop without my foot on the brake. It just scrambles my brain sometimes.
As well as when my dead silent truck accelerates when I let up on the brakes a bit.

It's hard to untrain my instincts

Yeah, definitely. I'm finally getting used the to auto-hold, which works fine most of the time, and it is very cool.

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