Slight brake pedal stutter after new pads

[PranK]

Hi guys, 

I just replaced my pads with blue stuff and flushed fluid. The pedal and brakes feel fantastic but I'm getting very slight pedal stutter under any kind of braking. Not every time, maybe 1 in 10 and not under any heavy braking, mostly occurs as I'm reaching a stop.

It feels like abs engaging but it's so fast, there and gone in under a second and no abs flash on the dash. 

Any ideas what could be causing this?

[GTSBoy]

It's almost certainly going to be some amount of pads compound transfer onto the rotors. It will probably go away after you've run them for a bit. If not, pull it all out, lightly sand the rotors, scuff the pads, and rebed.

[PranK]

Thanks, will do that. 

Thankfully they still feel great.

[MBS206]

What bedding in procedure did you use?

 

When you say stutter, what exactly do you mean? Like it feels like someone letting go of the brakes momentarily and regrabbing them again to get you to stop?

Re-reading your post, and that is what it kind of makes me think you're explaining, like theres a little bit of a jolt, likely just as you're reaching a stop.
I've only had this issue once. And if its caused by what caused mine, you will want to get the car up on stands again and check it over. Mine was a case of a caliper mounting bolt coming out and letting the caliper rotate on the other remaining bolt and gave play in a wheel as it came to a stop. But not every stop either!

Edited Friday at 05:09 AM by MBS206

[PranK]

The stutter is almost entirely in the pedal. I don't feel the brakes release and reapply as you would with ABS engaging but the pedal feels that way, without the brakes releasing. It only lasts for less than a second and the pedal is fine again. It's hard to explain, sorry. 

I'll get under this weekend and just double check everything is tight. Fluid is at max where I left it.

[MBS206]

Sounds more like what Brad said, that it's mainly transfer.

What pad bed in procedure did you use, and did you replace/machine the rotors, or just swap pads?

[PranK]

I did a few 80-0 stomps. I then just rode the brakes while I applied throttle for a while to get them nice and hot. I live on a big hill and have been down it a few times also with stomps and brake riding.

[PranK]

I might do a few more high temp bed ins as described here. 

I have a nice quiet 80kph road right near me. 

How To Bed-In Your EBC Brakes For Street Or Track Use - EBC Brakes https://share.google/AjnOTILXoiqQnLu8p

 

[GTSBoy]

Yeah, you need to do it properly. You need to start out slow and gentle, ramping it up until they are good and hot, but not cooking, then roll off the other side (instead of letting them cool down quick).

[MBS206]

Also, if you didn't machine or replace rotors, it will make it harder to bed the new pads properly. It is something I'll advised to do. And yes, I've done it many times before, and will likely do it again, so no judgement here if you didn't replace or machine the rotors.

[PranK]

The rotors only have about 5k on them so I didn't worry about the machining. 

[Murray_Calavera]

Sounds like doing a track day will resolve all your issues. 

[PranK]

45 minutes ago, Murray_Calavera said:

Sounds like doing a track day will resolve all your issues. 

You know what? I reckon you're on to something.

[MBS206]

2 hours ago, PranK said:

The rotors only have about 5k on them so I didn't worry about the machining. 

Murray has the right idea! Or just pretend you're a tow truck driver, they drive around as if it's a race track. Pads will be bedded in in no time! Or you'll arrive at an accident scene quickly...

[Dose Pipe Sutututu]

A great time for Alcons.

https://www.coore.com.au/alcon-front-bolt-on-big-brake-kit-bmw-m3-e90

 

[niZmO_Man]

No shit I've fixed shudder/noise by slamming on the brakes a couple of times from 60-80 km/h.
If they still made noise after that, take the pads out, rub on concrete floor/file the friction surface, install and bed in.
Fixed like 3x QFM pads for me.

Oh and if you're tracking it, never skimp out. You may recall my R31 at Oran Park many years ago with melted pads...

[Duncan]

what sort of caliper are they? If they are a slider and you gave everything a good clean, you might need to regrease the pins.

My guess though is they will come good after some abuse as suggested above

[PranK]

Ok so we have a smoking gun. 

A few weeks ago I had to replace a speed sensor that I'd fit incorrectly. I replaced the sensor and everything was fine with no lights or codes thrown any longer. 

When I was doing some more bedding in yesterday I got ABS and traction control lights again and, considering when this happens those things are disabled, the pedal went back to normal with smooth braking and no hiccups. 

The codes thrown are for the same speed sensor that I replaced. When I looked at the sensor I took out it looks like the tip of the sensor is damaged. So whatever happened to it, perhaps it has damaged the magnetic ring on the bearing (that I only replaced the other week).

I'll get my boroscope in the hole where the sensor goes and see if there is any damage in there. Hopefully just the tip of the sensor is in there and the bearing is fine. 🤞🏻 

It's worth noting also that the pedal hiccup happens more often and for longer periods now and totally goes away when the codes are thrown again which happens usually after 5 or so minutes of driving.

Love all your help here as usual guys, thanks!

[PranK]

On 13/09/2025 at 5:54 PM, Duncan said:

what sort of caliper are they? If they are a slider and you gave everything a good clean, you might need to regrease the pins.

My guess though is they will come good after some abuse as suggested above

Yeah they are sliders and this was in my head before I worked out it was the speed sensor.

[PranK]

Just to be clear, there were no lights or codes when the hiccups were occurring. Also nothing noticeable in the cars' braking. It brakes fine and the dash is clear. I only made the connection when it did throw a code and suddenly, despite the lights, it felt great again.