[GTF34]

So I recently posted a thread about a possible slipping clutch codes which is still ongoing and in the process of being quoted for the clutch replacement.

However, I have something else now that seems to be getting noticeably worse.

I know that my car, a 318 GT (2013) has brake assist on a hill. So when on a hill leaning backwards, the brakes release a little bit later to help give the driver time to get the clutch point or the equivalent of a hand brake.

However, I am now noticing it doing this simply by being on a forward-facing inclination.
Engine running, foot on the brake, not in gear. The weight of the car is all on the brakes. I fully release the brake, and the pedal comes up, but brakes take a second or two to release, so much so that you can hear them slowly releasing and the car then moves forward.

I thought this was only when the car was inclined backwards as I have never felt it facing forwards. But it also feels like it happens during normal driving.

Has anyone experienced this? Like I say I am only posting this as I feel that there is an issue as I have never experienced this before.

TIA

[ssozen]

Mine is auto, uphill brake support is documented to last for 2 secs, then release. It is a precaution if car is in neutral, that it will roll back. It also happens for forward inclination, if gas is not pressed it waits 2 secs.

Seems normal operating status.

P.S: Just thinking - no inclination sensor, apply always?

[GTF34]

So I was driving back from Lisbon to the Algarve last night at 23:30 trip started and is a 2.5-hour drive.
I'm cruising with Cruise control at 125km/h on the motorway and suddenly the car brakes by itself as If I was braking fairly heavily...

There were no other cars around me, it had just started to rain as we were heading into lightning in the distance (where that came from in July is beyond me!).

Anyway, I knew something was not right. the issue with the delay on brake release had also become a lot more noticeable in recent days so much so that I had already spoken to the garage about it and we were monitoring it.

I slowed down a little obviously to around 100km/h and the car continued as normal for a couple more km and then again, started to brake by itself quite abruptly but then released again.

I thought it may be something with the Cruise control so I deactivated it and drove normally, still in the rain. A few more km but even slower now doing around 70km/h and again the thing starts to brake by itself quite hard and then released again.

I now knew I was not going to get home safely on my own so pulled into the next service station on the motorway and called road assistance.

Back home now after 4.5 hours waiting for the tow truck and a taxi at 01.30 in the morning, but I was wondering if anyone else might have any insight as to what this may be.

I'm guessing electrical and to do with ABS, but then what would that have to do with the delayed release on the brakes that has been getting slightly worse?

Appreciate any feedback anyone may have.

[GTF34]

Furthermore after doing a bit more digging, I thought it a good idea to add the following link which pinpoints EXACTLY what I have been experiencing...

https://www.bimmerfest.com/threads/b...ction.1394662/

In a nutshell:

Jan 25, 2024
After a long time investigating this problem, I concluded that it has nothing to do with changing modules, much less spending a fortune for nothing...
The problem is caused by the Dry Braking system, for those who don't know, BMWs have this braking system, which involves "drying" the discs so that they are more effective in rain. This system is activated by the automatic windshield, that is, when it rains and the rain sensor activates and turns on the dry braking system, which starts operating every x time from around 80KM/h. This system should exert 1bar less pressure on the pads in order to only clean water and not be felt on the floor of the vehicle. When this system is malfunctioning, it causes braking (increasingly stronger over time) which causes the car to slow down momentarily. It could also be a problem for some people who feel "pits" lose slight power in some situations. (but the common point is that it is raining)

To resolve the problem there are several options:

1st replace brake oil (who REALLY knows how to do that), the oil could be compromised. Check the braking system.
2º Do not set the windshield to automatic (use manually)
3rd code the car to disable "Dry Braking"

Note: this situation is only for those who do not see any errors on the dashboard, the OBD scan does not show errors in the ABS, DST or DSC system

I hope to help many people because BMW just wants to suck us in...

[Mkesler75]

I’d change the brake fluid. Should be done every few years anyway. Easy process.

[GTF34]

OK More info on this case...
Car was in BMW for a week whereby they had never experienced anything like this before.
Long story short fixing what was needed would set me back 6.500 EUR give or take a few bucks.
So I have now sold the car as was. Sorry to see that back of a great vehicle that has served me well over 8 years and 250.000km

Now looking at a 2020 X1 or a 2018 420d

Edging towards the newer X1