Front Brake Discoloration

[greggk]

Have a year old 35is with 326 wheels. I'm meticulous in cleaning wheels with soap and water every few weeks.

Today I noticed that the front only brake assembly piece that has the big single hole in it has begun to get black marks on it that elbow grease won't remove.

Wanted to see if anyone knows what this is and how can I remove it. Not sure if some oxidation thing is happening or what. Never noticed this before.

The normal gold oxidation on the inside of wheel went away normally when I drove around the block a few times after washing the car, but the piece I'm referring to did not.

Thanks

[juhap]

A photo would help, but I think you're referring to the same part that turned bright rusty orange in my car. I even considered having it painted until I found out that it's just a plate that costs about 15 - 20 dollars plus labor to replace.

[jparnes1]

That part is called the rotor. The marks are coming from your brake pad. How long have they been there? It seems like this would self correct as the pads wear marks off the metal

[greggk]

I attached a photo.

Its the flat silver piece in the middle of the photo that has the black spots on it. Maybe its been there and I havnt noticed , but not likely. I noticed when cleaning my wheels this weekend.

I am positive the piece was previously all silver.

I saw a Z4 28 version today for a comparison and it had a different front brake configuration so that didnt help.

Thanks

[HerrK]

Originally Posted by greggk

I attached a photo.

Its the flat silver piece in the middle of the photo that has the black spots on it. Maybe its been there and I havnt noticed , but not likely. I noticed when cleaning my wheels this weekend.

I am positive the piece was previously all silver.

I saw a Z4 28 version today for a comparison and it had a different front brake configuration so that didnt help.

Thanks

The "piece" you are reffering to is the "caliper spring clip" It is plated spring steel. As the environmental laws in the US and EU get stricter it becomes an increasing engineering challenge to prevent discoloration of the material. It is only cosmetic and won't affect function. They hide these ugly parts on BMW Performance calipers - Oh yeah, BMW does not offer those yet (I'm trying to be optomistic) for the E89 Z4.

[juhap]

Originally Posted by greggk

I attached a photo.

Its the flat silver piece in the middle of the photo that has the black spots on it. Maybe its been there and I havnt noticed , but not likely. I noticed when cleaning my wheels this weekend.

Yep, that's the one. It will turn orange next

[ManiacGT]

..and I thought I was OCD about cleaning!

[z4z4z4]

greggk
Here's a Norway owner's solution to your iS brake spring spoilage. Nice.

http://e89.zpost.com/forums/showthre...7#post13534477

[greggk]

Here's a Norway owner's solution to your iS brake spring spoilage. Nice.

Is that the actual rust/discloration or is it painted?

If replacing the part is only $15-20 as previously mentioned, maybe thats the way to go say every 12-18 months, as mine didnt start to turn black until month 12 of owning the car. And it hasnt even started to go orange yet.

[raven333]

You can rub ACF50 on them which stops the corrosion, but if they have already gone you cannot do anything but paint them. They should also be replaced when new pads are fitted!!!!!
As a master of corroded callipers, big argument with BMW, I can attest to the fact that probably 95% of cleaning agents used on wheels cause major discolouration issues over time.
The only one that does not do this is BMW's own brand but this is a Sonus product relabelled .....

[nicknaz]

wow great upgrade to M calipers there

[Rafale]

Originally Posted by z4z4z4

greggk
Here's a Norway owner's solution to your iS brake spring spoilage. Nice.

http://e89.zpost.com/forums/showthre...7#post13534477

Where can I get this?