[BeeEhmWie]

Hi there,

I’ve got a ‘24 330i with the optional Msport brakes.

Is it just me or are the brakes very touchy and nonlinear on initial application? Like the first couple % is smooth then it ramps up big time then it becomes linear again.

Is it the master cylinder?
Is it the power brake assist?
Is it a mismatch between the bigger brakes and a (maybe) stock 330i master/power brake system?

Must be super careful on initial brake to go over the 5-10% “hump” in brake application smoothly. Super whack, it should be perfectly linear.


My Corolla had nicer brake pedal application, just shitty small brakes.

[Jerolec]

I have a 2019 with the Msport brakes too and they are very sensitive at low speed and a bit vague when braking strongly at 50mph+ speed.

My theory is that at low speed they are very sensitive but what's making them non-linear is not the brake themselves but the engine braking effect used to recharge the battery. When the transmission is downshifting from 3 to 2nd and 2nd to 1st you really can feel the engine braking and that is creating the non-linear feeling on the brake pedal and even the car lurching (pretty ordinary for a nice car like that I would say).

Pay close attention when you slowdown to a stop and look at the battery icon in your cluster when the car downshift.

[cyam]

Just the pads. Different pads can eliminate this.

[Jerolec]

You experienced this with OEM pads? They had changed discs and pads when I bought the car. I thought the twitchy feeling would have desapeared over time or after the break in period but no. Might worth trying while the discs are not much used.

[helmet91]

I went from the stock 1-piston gray brakes to M-Sports - I also had Turner stainless lines installed while using RBF660 fluid. On stock pads and discs the setup has been fantastic.

Originally Posted by cyam

Just the pads. Different pads can eliminate this.

He has a 2024... it seems OEM and iSweep are the only options for the revision thus far.

[BeeEhmWie]

Originally Posted by helmet91

I went from the stock 1-piston gray brakes to M-Sports - I also had Turner stainless lines installed while using RBF660 fluid. On stock pads and discs the setup has been fantastic.




He has a 2024... it seems OEM and iSweep are the only options for the revision thus far.

I played around with it. It’s mainly the transmission. If I put it into neutral it’s more linear. Sometimes the engine braking / clutch engagement is strange when getting on the brakes initially.

However when in neutral and then applying the brakes while coasting, it’s still touchy but more linear.

Also, while the brakes are touchy, when you actually lay on them the stopping power isn’t that great, it falls off in linearity.

A lot of initial bite but not a lot of actual power.

[BeeEhmWie]

Originally Posted by cyam

Just the pads. Different pads can eliminate this.

Hopefully less initial bite but still solid friction

[Jerolec]

Same experience on my 2019 with M sport brakes. Will change the pads for probably Project MU PS and see if there's a difference in the initial bite and hard stop. Will let you know in a month or so.

[snekjumpr]

Originally Posted by BeeEhmWie

Hopefully less initial bite but still solid friction

Ceramic brakes should solve the initial bite issue caused by the OEM semi-metalics and eliminate jerky stops. I'm still on the fence between the iSweep 1500 and 2000s...

[BeeEhmWie]

Originally Posted by snekjumpr

Ceramic brakes should solve the initial bite issue caused by the OEM semi-metalics and eliminate jerky stops. I'm still on the fence between the iSweep 1500 and 2000s...

Good suggestion

[BeeEhmWie]

Originally Posted by Jerolec

I have a 2019 with the Msport brakes too and they are very sensitive at low speed and a bit vague when braking strongly at 50mph+ speed.

My theory is that at low speed they are very sensitive but what's making them non-linear is not the brake themselves but the engine braking effect used to recharge the battery. When the transmission is downshifting from 3 to 2nd and 2nd to 1st you really can feel the engine braking and that is creating the non-linear feeling on the brake pedal and even the car lurching (pretty ordinary for a nice car like that I would say).

Pay close attention when you slowdown to a stop and look at the battery icon in your cluster when the car downshift.

Yea it’s the downshifting for sure. I don’t have the battery indicator you speak of but that’s the main thing.

I’ve put the car in N and smoothly braked down to 0, although the brakes are still very touchy even in neutral.

However it doesn’t have those weird irregular and way too powerful downshifting as in D.

I notice too the torque converter must be like really trying to lock up and/or engine producing tons of torque at idle, because if you let go of the brakes the car jumps forward quite quickly.

Horrible drivability honestly, shocked. And I know others have said this. Overall still a great car, just a pain in the ass sometimes stop and go.

I notice Comfort+ transmission smooths it out slightly over Eco Pro

[RCM78]

I feel the main offenders are the pads. It’s even worse in cold/damp weather. I have a set of Project Mu PS pads ready to go in when the weather warms up in NJ.

[Jerolec]

Originally Posted by BeeEhmWie

Yea it’s the downshifting for sure. I don’t have the battery indicator you speak of but that’s the main thing.

I’ve put the car in N and smoothly braked down to 0, although the brakes are still very touchy even in neutral.

However it doesn’t have those weird irregular and way too powerful downshifting as in D.

I notice too the torque converter must be like really trying to lock up and/or engine producing tons of torque at idle, because if you let go of the brakes the car jumps forward quite quickly.

Horrible drivability honestly, shocked. And I know others have said this. Overall still a great car, just a pain in the ass sometimes stop and go.

I notice Comfort+ transmission smooths it out slightly over Eco Pro

When I got the car with brand new OEM pads and discs the brakes were very touchy but it kind of faded out a bit over time or just got use to it. They were also very clunky when reversing but it got away when i greased the pads. Strangely, dealership didn't put any when installing them...

The worst is really the battery regen when downshifting from 2nd to 1st gear.
Don't wanna go that route yet because car is still under warranty but I read on the xHp website that with the transmission flash you can prevent the car from downshifting into 1st gear. I don't know if anyone ever tried it and if it would "resolve" the jerkyness but would definetly consider it in year when warranty ends.