Brakes release when stopped on slope (Powerboost)

[Jerry Can]

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?

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[AllFordTech]

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.

 

[Mxp0w3r25]

Very interesting, I have noticed when I come to a stop on my powerboost it will try to creep forward a bit. I feel like I have to put extra pressure on the brake pedal to ensure it doesn’t creep.

 

[imnuts]

If I'm lightly pressing on the brake, it will eventually want to start to creep forward, but it takes a little. I just have to press on the brake harder and problem solved

 

[Jerry Can]

If I am reading this correctly the truck moves forward even when your foot is on the brake.

That is correct; the truck moves forward and then slams on the breaks again. The first couple times this happened, I thought I might not be pressing the pedal hard enough. However, the 3rd time and onward I’ve made a conscious effort to press the brake pedal down hard, yet the truck still rolls forward a few inches.

 

[Jerry Can]

Very interesting, I have noticed when I come to a stop on my powerboost it will try to creep forward a bit. I feel like I have to put extra pressure on the brake pedal to ensure it doesn’t creep.

If I'm lightly pressing on the brake, it will eventually want to start to creep forward, but it takes a little. I just have to press on the brake harder and problem solved

My issue isn’t creep from not pressing the brake pedal firmly enough. I can press it down as far as it will go, and it will still release and roll forward a few inches before it automatically slams on the breaks again

 

[thebigdu]

Very interesting, I have noticed when I come to a stop on my powerboost it will try to creep forward a bit. I feel like I have to put extra pressure on the brake pedal to ensure it doesn’t creep.

Exacy this!!! I drove my wife's CR-V today for the first time in a while, and I couldn't believe how lightly I had to hold the brake to keep from creeping. Same with my old GMC Canyon. It's almost dangerous how much pressure is required to hold the brake in my F-150. I've started using Auto Hold to help out, but that's taken some getting used to. I also have noticed the truck occasionally seems to release the auto hold and then regrab after maybe 1/4 second.

 

[thebigdu]

My issue isn’t creep from not pressing the brake pedal firmly enough. I can press it down as far as it will go, and it will still release and roll forward a few inches before it automatically slams on the breaks again

You need to get this thing to the dealer stat, man. That sounds scary.

 

[Bikertrash]

had a 2021 PB that did not have this issue (lots of others) My new 2022 I have only had for 100 miles but have experienced the momentary release with auto hold twice. I’ll have to keep monitoring it

 

[Snakebitten]

No way is it normal for the calipers to release from the rotors if you have the pedal pushed. Nothing about the Powerboost is meant to override the driver's intention of traditional braking.

What IS different about the Powerboost is the design of the brake system regard vacuum. Since the ICE isn't running often, the required source of vacuum for the brake boost is electric. You can clearly hear it running when you press the brake in Park and the engine isn't running. It spools up everytime you press the brake pedal.

I wonder if your electric brake boost is malfunctioning?

I have a steep incline to get into and out of my barn. I use the brakes to gradually come down that incline every time I leave. I would freak out if the brakes released for even a second. And it's steeper than any parking garage I've ever been in. I have to use 4A to get up it.

 

[Snakebitten]

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?

 

[Oxford_Powerboost]

Mine has always crept an inch or two after being stopped for a bit. Even on level ground after being stopped (on auto hold as well) for like 5-10 seconds, it’ll creep and then grab the brakes again

 

[Snakebitten]

Hmmm. I wouldn't like that feeling.

I love technology and the amazing features that come with it. But my BRAKES are not up for some kind of interpretation of my intent.

I can live with the ACC having influence over creep and adjusting, but not overriding my boot on the STOP pedal.

 

[UGADawg96]

Trucks with these symptoms need to be checked out by a dealer. My ~5,000mi Nov 21 built PB's brakes feel like old school brakes. I can't tell as a driver if they are brake by wire or not. Nor can I tell when the brakes are doing regen versus actual braking. I've never had the truck move when my foot has been on the pedal. Sucks you guys are experiencing this. It almost seems like some type of unintended acceleration. Just yesterday I saw a recall blast for a software issue with some of the mach-e having as unintended acceleration issues. May not be related.

 

[UGADawg96]

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.

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