What does it take to fix 135 front brakes?

[redrum36]

Do I need to go to Stoptechs? My pedal goes to floor on track. Fluid is srf. Something is wrong or the brakes just suck that bad? Hawk 70's not lasting long and very uneven wear. Inside pads thin plus tapered toward "top" and trailing edge too. Where's the cheapest place for ST40's?
Thnx

[N55_BBM]

tracked my car 3 times. 2nd time i bled them before tracking and by the end the pedal was complete spongy and shitty, dealership said my rotor was warped and changed the front ones. that was in november of last year

tracked the car yesterday for the first time ever since and my brakes now suck again, not spongy but I need to press the pedal SO far in to be able to make it stop. will bleed brakes this week and if that doesn't solve it to the dealership we go.

i'm kinda disappointed in these brakes to tell you the truth. they do an awesome job stopping the car.. in the first two heats or so of tracking. then they become shit...

[masetcp]

look at the thread for the fix for the brakes. someone is making new pistons for the brakes. basically a rebuild kit. should fix your problems.

[redrum36]

I had similar issues. Replaced fluid with SRF. Next time out, same pedal to the floor crap. Never experienced this before in my 150 track days. i am running SRF AND hAWK 70'S. The pistons are not going to fix this problem. it is a cooling problem or the pistons wouldn't shatter in the first place. The freakin rotors are too small for the calipers. I had st40'swith 355x32 on my e46 m3 with brake cooling ducts. that really helped. With this car, there is hardly any room to get ducts in there and nothing available to attach them too. After 12 years of BMW's I am feeling frakked by them. I should have bought a Lotus or Mustang. I will be buying stoptechs and selling the 135 brakes. BMW doesn't even have a part number for the caliper reting bolts wich should be replaced every time the calipers are replaced, which is every time we change pads! WTF! One of my bolts backed out and bent the other, That's how i found out about that, BMW still does not have a fix for that either.

[N55_BBM]

One thing I had my eyes on that could potentially help the problem is the performance bumper with brake ducts. But at a little over $700 I don't know that I can afford it right now. Still hurting from the $2400 spent with new wheels, tires, TPMS, and mounting and balancing...

[Dackelone]

^^It could also be the SRF that is coming into play.(I know that the 135i calipers aren't really cut out for track use!) Did you guys read what berk said about the SRF and boiling. Basically that onceyou get SRF really hot... it will become just as good as $3 brake fluid - as far as brake pedal feel goes. Sre it had a high boiling point... but Berk said that they prefer another brake of brake fluid. It was a really good thread. Look it up. It was just last week.


Dackel

[N55_BBM]

I'm running on the stock fluid and wouldn't want to change to avoid warranty issues... is SRF the stock one?

I think my driving has gotten to the point where I need to upgrade something to stop messing the brakes up... but now comes the problem with me living in an apartment and having limited tools and being on a very limited budget right now... god...

[Focusedintntions]

I run Motul rbf 600 and have had no issues since i put that in there. Run cool carbon pads as well and been running great. Only issue i've had is the uneven wear also which is pretty displeasing.

[N55_BBM]

so good news is that unlike the last time this happen (which the dealership diagnosed as a warped rotor), my pedal isn't spongy and it's not vibrating. Only problem is that the travel distance has really increased, I need to press it a lot harder to get the car to brake with the same intensity.

Prob thinking it's just air in my brake lines or I might've boiled the fluid? Does this mean I need to bleed the brakes or do a full flush?

[pixelblue]

you got air in your lines. need to do a better job bleeding

[N55_BBM]

How do I know whether to do a bleed vs a full flush?

[DriveHard]

Originally Posted by N55_BBM

How do I know whether to do a bleed vs a full flush?

Bruno... knowing that you have maybe 1 more event this year, just bleed them with the bottle I gave you. when you do it, just use up as much as you can..it will be kinda like a flush, but not 100%.

let me know how it turns out.. BTW how was your ride back !! we hit some heavy rain, but got home in record time.. was in my garage by 8pm...

[adrean8j]

I find this all very, very interesting...I have tracked my car multiple times and NEVER once had pedal to the floor or sponginess (just a little fade near the end of my sessions).

My thoughts:

Brake fluid: Use the stuff pictured below. It is top-notch and has served myself and others well:




Flush/Bleed: Make sure this is done properly. I personally take it to my local (depending on if I am in SC or GA) TRUSTED shop.

I have done 4 HPDE/AutoX's in 12 month time frame (2009/2010)...have had the car since 2008 still on original brake pads....no way they should be wearing like that.

CAVEATS:

1. I have the slotted/drilled front rotors - don't know how much, if any, difference this makes but I felt I should mention it.

2. I have the performance front bumper with the extra cooling venting to the brakes.


Just one other observation:

The "vibration" during braking...are you sure it isn't your ABS kicking in? I know it feels very strange to most people through the brake pedal when it occurs if they are not used to it.

[redrum36]

That bumper sounds like a good idea! Not bragging, just sharing some background trynig to validate my opinion based on my personal experience: I have done about 150 track days including some long sessions and long days. I've driven Road America, Mid Ohio, Grattan, Gingerman, Autobahn, Putnam, VIR, Blackhawk Farms, and the Milwaukee mile. I've done open lapping, DEs, and NASA Time Trials. I am an instructor for NASA, AUDI, LAPS, BMW, Track Time, and others. I ran Time Trials in NASA and win Regionals in TTA in 2009, 2nd in 2010, and 3rd in TTB in 2008. I only mention this becasue I have done a few laps and know something about brakes. Not EVERYTHING but SOMETHING. Of course I flushed the system etc. I usually use ATE Blue or Motul. Like to alternate colors to show that the fluid has been completely changed. Went to SRF because they say it is the best. No air in the lines. These brakes do not work for me. They may work for you, but they cannot take the pounding necessary to play in my world. I am switching to Stoptech and will make my NEW BMW Phoenix Yellow brakes available FS on the forum, once I switch to the Stoptechs. Your results may vary. This does not mean I am better than you or anything, just my own experience and my humble opinion. I hope it all works out for everyone.
Peace!

[adrean8j]

LOL...if we had known your full credentials BEFORE then I wouldn't have posted the basic stuff above(have known people with many trackdays under their belt and still didn't know how to change the oil....) I haven't heard of the SRF, or maybe I did in passing but never paid attention due to the blue/gold stuff working for me. (And the 150 track days from before just didn't click the first time I read it )

The ducting from the performance bumper is not really that advance persay.

I think it probably helps but I don't think it will help you in your situation if you are cooking the brakes that bad. Expensive experiment I would think. I would go for the ST's myself if I was able to do many more trackdays (still might in the future...car is a constant work in progress)

Curious how long was the sessions that were causing you to have this problem?

[N55_BBM]

For me it was 4 sessions 20 min each. By the third session my brakes get crappy and I need to depress it much harder for the same braking power.
Same story twice

[N55_BBM]

Originally Posted by DriveHard

Bruno... knowing that you have maybe 1 more event this year, just bleed them with the bottle I gave you. when you do it, just use up as much as you can..it will be kinda like a flush, but not 100%.

let me know how it turns out.. BTW how was your ride back !! we hit some heavy rain, but got home in record time.. was in my garage by 8pm...

Bought the flask and hose and will try it later this week. Thanks for the bottle and the advice!

[DriveHard]

Originally Posted by N55_BBM

Bought the flask and hose and will try it later this week. Thanks for the bottle and the advice!

awaiting your call to the "technical hotline" later this week...

[redrum36]

i bought Stoptech Trophy brakes STR60 for front. Still waiting for them. They come with 'cheese grater' rotors. 8^( These brakes are bigger and have better thermal properties but I still want to get more air in there. i have a few ideas.
thanks for all of the comments. I should have realized this before but those OEM brakes are so big I thought they would be great. Also, dealer replaced left one previously and now the right side but the new one is grey! they no longer have the yellow! this is going to make them hard to sell! Also went back to ATE blue because SRF is too expensive and I like to alternate colors so i can see the "old" stuff is gone.
thanks again.
d

[3002 tii]

I know Turner sells a brake cooling kit, maybe it's something you could look into. Or do a fresh flush before each event instead of once per season?

[N55_BBM]

Originally Posted by DriveHard

awaiting your call to the "technical hotline" later this week...

Operation brake bleed yesterday was a great success, thanks for the fluid and the help! Hardest part like I said was finding the lug nut my friend's dog sneakily stole and hid while we were at it. After 40 min of searching his backyard we gave him a second one and observed him from a distance. He took it right to the same spot he had hidden the other one .

I had a lot of air in the brakes. Bled them all but in the end I ended up using maybe only 200ml out of the 355mlk in that bottle. I kept bleeding a each one until I filled the little container, looking in retrospect I should've kept bleeding even more until I had no more fluid left, oh well..

As far as the brakes' performance goes, the pedal is no longer traveling as much as it did before. It's a lot firmer and has a better initial bite. It's much better but it's not as good as it used to be obviously.. but that's probably normal since I have old fluid there and since after 18k miles and 3 track days my pads are probably worn. At least the pedal is no longer traveling too much, there's no sponginess, no vibration, nothing abnormal... which is always good!

However, since this past week I noticed that my brakes are starting to squeal when I start breaking (squealing stops after 2-3 seconds on the brakes, and it's mostly under light brake load). Is this caused by a worn out brake pad? I have to take the car in for service in the next 2-3 weeks and am thinking I should just tell them to inspect the pads.. I know BMW US says 2 years to change fluid and brake pads and it's only been 1yr 3mo since I got the car, but 18k miles is a lot and I don't exactly drive like a grandma.

[adrean8j]

Originally Posted by N55_BBM

However, since this past week I noticed that my brakes are starting to squeal when I start breaking (squealing stops after 2-3 seconds on the brakes, and it's mostly under light brake load). Is this caused by a worn out brake pad? I have to take the car in for service in the next 2-3 weeks and am thinking I should just tell them to inspect the pads.. I know BMW US says 2 years to change fluid and brake pads and it's only been 1yr 3mo since I got the car, but 18k miles is a lot and I don't exactly drive like a grandma.

Normal and typical...had this happen with my old E39 and with my E82...pads are fine, rotors are fine....that being said I think it has something to do with outdoor temps and pad temps(this by no means is definitive and just a guess). Does it go away eventually or does it sound like that when the car is fully warmed up (as in driving around town for 20-30 minutes?)