[Junaed08]

Just had my 428i brakes upgraded to M-performance brakes from stock BMW brakes non-msport. Brakes have been coded and bled 3 times yet i still have a bit of travel on them. Can someone please help me figure this out

Thanks

[cfm56d7b]

Was the installation done by a qualified shop?

Is the travel noticeable before the first bite can be felt?

[Junaed08]

Yup. I just checked on the forums my coder added 2NH, do i need to add SPBR?

[cfm56d7b]

Excellent thread to read:

https://f30.bimmerpost.com/forums/sh....php?t=1666002

[johnung]

Originally Posted by Junaed08

Just had my 428i brakes upgraded to M-performance brakes from stock BMW brakes non-msport. Brakes have been coded and bled 3 times yet i still have a bit of travel on them. Can someone please help me figure this out

Thanks

Make sure that brakes were bled with this BMW ISTA procedure. It’s the only way to shake loose air bubbles that are sticking inside walls of brake system components. Not doing it causes the exact symptom that you described.

https://youtu.be/o7XsCMqZXw0?si=aPG-jLvORlwxZW-s

[White435]

My M-Performance brakes were spongy even though I bled them with Motive Power Bleeder. After taking it to indy shop to bleed with ISTA the problem was gone.

[Junaed08]

Thanks guys. Got it booked in for Friday to get it done via ISTA 😁

[Junaed08]

Hi guys

i've had the brake bleeding routine done through ISTA today and still the guys cannot locate the problem. The only thing i can think of now is do i need new master cyclinder?

[TurboWeasel]

Are they the 370/345mm blue brakes? Did you do discs and pads, or just pads?

They can take an age to bed in fully and give a solid pedal. Just putting that out there.

[Junaed08]

The full kit. I’ve already done about 1500 miles since they’ve been added on. The garage will try again next week with a Hydro Brake Bleeder Kit

[TurboWeasel]

OK. Maybe there is an issue then as after 1500 miles you would expect a solid pedal.

[rlesko]

What kind of pads are you using?

Unless you leave the brake lines open for extended period of time, the The ISTA procedure shouldn't be necessary (albeit can't hurt if done properly). The real reason the procedure exists is for master cylinder replacement.

I clamped off my plastic brake lines while I painted my calipers and installed stainless steel braided cables once my calipers were ready and I don't have any spongy-ness. Obviously I immediately bled both sides of the caliper on installation.

Also, no new DSC should be needed for the brake kit.

[TurboWeasel]

During my VW days, they also cycled the ABS pump during a brake fluid flush. It's mandated in the procedure. I suspect it's the same for BMW dealers.

When I enquired as to why they do that, the VW master tech told it's to exercise the ABS pump pistons for a complete purge of every last scrap of old fluid. It's not just for master cylinder/ABS pump replacement.

Sounds plausible to me because unless ABS, TC or DSC is activated during normal driving, the ABS pump doesn't do a lot, if anything, so rotten old dirty fluid can linger in there.

[Junaed08]

just wanted to check because i've gone from stock brakes to m-performance will i need to replace the master cylinder?

[E90lova]

This sucks I can bleed my Audis of the same year range with just pumping the brake pedal and a catch bottle and there is absolutely no air in my Audis. The BMW is different but I did mine and no air bubbles. I am still questionable about the outside valve first inside valve second thing since Brembo states to bleed the inner valve first.

[E90lova]

Also I noticed the bleed sequence is different on that clip on youtube. Rear Left, Front left, Front right then last Rear right.

[johnung]

Originally Posted by Junaed08

just wanted to check because i've gone from stock brakes to m-performance will i need to replace the master cylinder?

The BMW instructions for the M Performance Brake Kit are meant to install it on any F30 so they are thorough. They make no mention of any master cylinder changes so you are fine.

BMW M PERFORMANCE BRAKE KIT INSTALLATION INSTRUCTIONS
https://rparts-sites.s3.amazonaws.co...Perf%20BBK.pdf

[co_440i]

I just had the coding done for my M Perf brakes on Tuesday, after originally installing a little while ago. Some of the sponginess remains, but the pedal travel-to-braking power is now far more linear, so it doesn't really bother me.

I want to have a shop install the Stop-Tech stainless steel brake lines before the winter, but I don't know if I'll get around to it. They're supposed to improve pedal firmness.

[rlesko]

Originally Posted by co_440i

I just had the coding done for my M Perf brakes on Tuesday, after originally installing a little while ago. Some of the sponginess remains, but the pedal travel-to-braking power is now far more linear, so it doesn't really bother me.

I want to have a shop install the Stop-Tech stainless steel brake lines before the winter, but I don't know if I'll get around to it. They're supposed to improve pedal firmness.

I did StopTech brake lines, rear M Perf calipers, and coding all in one go so I can't speak for the individual improvements of each step but...why didn't you put the new brake lines on during installation of the MP BBK? How old are your lines at this point? Probably not worth it to pay labor on installing the brake lines...

Wrt to pedal feel, its a bit hard to explain. The car definitely squats better under hard braking (makes sense, bigger rear calipers). The pedal isn't spongy or vague, but its not sensitive either. It took a little bit of getting used to but I have no complaints.

[co_440i]

Originally Posted by rlesko

I did StopTech brake lines, rear M Perf calipers, and coding all in one go so I can't speak for the individual improvements of each step but...why didn't you put the new brake lines on during installation of the MP BBK? How old are your lines at this point? Probably not worth it to pay labor on installing the brake lines...

Wrt to pedal feel, its a bit hard to explain. The car definitely squats better under hard braking (makes sense, bigger rear calipers). The pedal isn't spongy or vague, but its not sensitive either. It took a little bit of getting used to but I have no complaints.

I assume the current brake lines are original from manufacture, my 440i is MY 2017 built in either August or September 2016. I had a road trip planned through the mountains for my GF's birthday at the end of July of this year, my plan was to change lines when I did the rest of the project before that. But ECS Tuning sent me emails that they didn't know when the brake lines were going to be in stock and ship (even though I had placed the order and it didn't say out of stock on the site ) and I couldn't take the risk of the trip on the original brake kit, so I had to do the job and re-use the current lines. The SS lines didn't end up getting delivered until the second to last week of August.

That's definitely a good way to describe the pedal feel post-coding.

[rlesko]

Originally Posted by co_440i

I assume the current brake lines are original from manufacture, my 440i is MY 2017 built in either August or September 2016. I had a road trip planned through the mountains for my GF's birthday at the end of July of this year, my plan was to change lines when I did the rest of the project before that. But ECS Tuning sent me emails that they didn't know when the brake lines were going to be in stock and ship (even though I had placed the order and it didn't say out of stock on the site ) and I couldn't take the risk of the trip on the original brake kit, so I had to do the job and re-use the current lines. The SS lines didn't end up getting delivered until the second to last week of August.

That's definitely a good way to describe the pedal feel post-coding.

Ah, makes sense. Well to be honest, if you're mechanically inclined at all you can swap the lines relatively easily. You just need the appropriately sized flare nut wrench. bleed the caliper on both sides after the install, minimize the amount of time you leave the brake lines open to avoid introducing air into the system.

Btw, I had a similar negative experience with ECS tuning, and for that reason, I won't order from them again. Their website listed the item as 'in stock'. A week later I had to contact them wondering why I hadn't gotten tracking info yet, and then they notified me the part was on backorder. I told them to cancel the order since they listed incorrect inventory status on their website (lead time was like 4-6 weeks) and they gave me a bunch of trouble over it. Eventually I had to initiate a chargeback against them. Absolutely terrible company.

[Alarbus]

Originally Posted by johnung

The BMW instructions for the M Performance Brake Kit are meant to install it on any F30 so they are thorough. They make no mention of any master cylinder changes so you are fine.

BMW M PERFORMANCE BRAKE KIT INSTALLATION INSTRUCTIONS
https://rparts-sites.s3.amazonaws.co...Perf%20BBK.pdf

This is true. The BMW instructions are only for the calipers, pads, and rotors. (And coding)

However, after having a local shop bleed my 440, it's still shy of the feeling from my 335, so I started looking at parts numbers. If the car comes with 2NHA, at least for the 335, it'll have the master cylinder and brake booster that would come on the M3/M4. If you retrofit SPBR, it will be different, and the pedal will feel different, even with a pro bleeding it with much fancier brake fluid.

I know this because I have the two cars parked next to each other, and I had just refreshed the 335s pads and rotors with OEM, and put all new on the 440, and can drive them side by side. The 440 is probably 95% of the way there, but I didn't feel like chasing the last 5% for a daily driver by swapper the MC and booster. But they are different.