BRAKE ISSUE WITH 135i CALIPERS

[cuizhuoyi01]

Originally Posted by Evolution Racewerks

True, however the Evo and STI with the 4 piston caliper were also made by Brembo as well.

Now I'm not saying that it's not the caliper issue, it might end up being so. However, to properly figure out what has gone wrong, we need to look at the situation objectively instead of assuming things and start pointing fingers. By doing so, we may not look at all the variables and miss the solution.

I have NEVER seen caliper pistons come apart like this, very puzzling mystery.

evos' owner never had problem with caliper piston.maybe because the piston is steel.

[atr_hugo]

It's not cracking per se - but rather disintegrating - YIKES, those pix are scarry!

This thread has gone 'sticky'.

[bluemoon]

Maybe this has happened before but I've never heard of caliper pistons crumbling like this at any level of racing. I hope BMW/Brembo step up to the plate on this problem. I don't know how anyone can have any confidence in the calipers after looking at these photo. Not

Any update on the rear calipers yet?

[WAY]

I don't think the rear caliper is going to be an issue as it is the front brakes that does all the work.

[bluemoon]

Originally Posted by WAY

I don't think the rear caliper is going to be an issue as it is the front brakes that does all the work.

Normally that's true but with our cars leaving DSC on and an extremely hot rear caliper is not out of the question.

[larryn]

Originally Posted by WAY

I don't think the rear caliper is going to be an issue as it is the front brakes that does all the work.

The rears make that major chatter when actuating the E-LSD. People have asked me about it as I had driven by them on the track and at autocross.

Granted, the piston is bigger in back, I wouldn't rule out the rear, as it continually hammers the pad against the rotor.

If you're thinking this is heat related, my back calipers discolored long before my fronts did...

I'm thinking it's material related.

[Evolution Racewerks]

That's assuming that the pistons aren't steel in our 135i. We don't know that yet as nobody has found out whether they're steel or aluminum.

Originally Posted by cuizhuoyi01

evos' owner never had problem with caliper piston.maybe because the piston is steel.

[Evolution Racewerks]

Another question for Scott and Way. Which caliper (driver or pass) is shown in the picture and is it the inboard or outboard pistons? Is there damage on both inboard and outboard pistons as we can only see one side?

[carno]

Originally Posted by Evolution Racewerks

Another question for Scott and Way. Which caliper (driver or pass) is shown in the picture and is it the inboard or outboard pistons? Is there damage on both inboard and outboard pistons as we can only see one side?

The photographs are on the driver's side (that's my thumb in there), but the passenger side had similar disintegration. I didn't observe any problems on the rear, but I didn't look closely either. I was able to compress the rear pistons by hand, but the fronts required a spreader and were very difficult even with the tool.

The borrowed calipers weren't nearly as bad, but they were only raced one weekend (3 sessions x 2 days). We didn't have time to photograph them after our last session at Sears Point.

[Evolution Racewerks]

So, I got some new information. The OEM Brembo caliper pistons have a ceramic insert at the end of the piston. That is what is damaged, the pistons themselves should be fine. This same type insert is used in the Porsche GT3 Cup Car calipers. Probably explains why the damage looks like it shattered and disentigrated instead of cracking that you would see with metal.

This issue points at potentially a heat related. It's not a metalurgic issue as they're not metal, but possibly a maximum temperature issue.

At the same time, it could also be the pads. Maybe excessive movement of the pad under hard braking causes uneven pressure on the piston. All the pistons inserts seem to be cracked on the same side in the same area.

[atr_hugo]

Fred, any idea of why they'd use ceramic in that application (other than as an insulator)?

[takahashi]

Thanks for that Fred. I think your explaination is the closest if not the actual truth.

Hmmmm....... does it mean I have confidence in buying the 135 again. I have not signed on the dotted line yet.

[cuizhuoyi01]

Originally Posted by Evolution Racewerks

So, I got some new information. The OEM Brembo caliper pistons have a ceramic insert at the end of the piston. That is what is damaged, the pistons themselves should be fine. This same type insert is used in the Porsche GT3 Cup Car calipers. Probably explains why the damage looks like it shattered and disentigrated instead of cracking that you would see with metal.

This issue points at potentially a heat related. It's not a metalurgic issue as they're not metal, but possibly a maximum temperature issue.

At the same time, it could also be the pads. Maybe excessive movement of the pad under hard braking causes uneven pressure on the piston. All the pistons inserts seem to be cracked on the same side in the same area.

sorry i don't understand what is insert???

[Papito135]

Subscribed. And my 2 cents. They are suppose to be high performance brakes from Brembo. If you upgrade from a regular brake system to a brembo brake system it will cost over $2500. If the oem brembo system can not even handle track runs then the oem should not be consider high performance or BMW and us with the brembo oem brakes just got ripped off by brembo. And let the conspiracy begins.

[davfagan1118]

Thought everyone would be interested in this patent. It mentions a lot of the reasons for using a ceramic insert in the piston.

http://www.wipo.int/pctdb/en/wo.jsp?...0&DISPLAY=DESC

I could also see that using a modified brake pad could cause uneven pressure on the piston insert and cause the disintegration.

[WAY]

Fred, the picture is inboard, but damage is on both sides. Your explaination makes sense, but if you look at my photo more carefully, you will see that there is a hairline crack in the middle as well, not just on the outside. Maybe Andrew@SouthernBM can confirm this but I believe he told me that they were crumbling inside as well.

Taka, don't worry about buying one of these cars. Just like you have put AP Racing brakes on your RX-8 race car, we should be doing the same thing on this car. I intend to do that at same stage and the time will depend on where we get to with this current issue. If it's a problem with the piston disintegrating completely, then AP Racing brakes will go on asap. If it's just the ceramic insert as Fred mentioned, then I am happy to leave it as is.

[Evolution Racewerks]

Well as you mentioned, the ceramic insert is there for insulation and offers excellent heat protection. This helps keeps heat from transfering to the piston which in turn transfers to the brake fluid. It is also cost effective.

Brembo uses titanium inserts for their top level racing caliper. Other than that, stainless steel inserts are used in other race calipers like the 6 piston aftermarket BBK's that we have on our car.

OEM manufacturers get a choice of all three. Obviously, OEM tends to go the cheapest route if they think they can get away with, which is probably the case here. Sucks that BMW is willing to throw in such nice calipers from Brembo and then skimp on a part that probably cost $20.

Originally Posted by atr_hugo

Fred, any idea of why they'd use ceramic in that application (other than as an insulator)?

[cuizhuoyi01]

Originally Posted by Evolution Racewerks

Well as you mentioned, the ceramic insert is there for insulation and offers excellent heat protection. This helps keeps heat from transfering to the piston which in turn transfers to the brake fluid. It is also cost effective.

Brembo uses titanium inserts for their top level racing caliper. Other than that, stainless steel inserts are used in other race calipers like the 6 piston aftermarket BBK's that we have on our car.

OEM manufacturers get a choice of all three. Obviously, OEM tends to go the cheapest route if they think they can get away with, which is probably the case here. Sucks that BMW is willing to throw in such nice calipers from Brembo and then skimp on a part that probably cost $20.

So if people want gop track, what should people to do with these stock caliper? just leave it? or get some aftermarket brake kit??

confusing :iono:

[takahashi]

I am sure there will be people outthere measuring the piston size and offer upgrade before hitting for track :wink:.

But will you trust them>????? hmmm

[cuizhuoyi01]

Originally Posted by squeak

if there covered under warrantie just keep getting new ones!!!

yeah, but the warranty does not cover our life.``:drinking:

I think if no track use, the brake should be fine for eveyday drive or even some mountain run.

[professor]

all this begs the question: if price were no object, what is the best brake kit option available for the 1er so that one does not have to tinker around or trial fit various pads; rather simply PnP?

[takahashi]

Originally Posted by cuizhuoyi01

yeah, but the warranty does not cover our life.``:drinking:

I think if no track use, the brake should be fine for eveyday drive or even some mountain run.

..... :iono: brake can get very hot in some....mountain run. If it fails there, it will be worst than losing it on the track - at least most track will have kitty litters.