[banshee28]

Need some help here. I THINK I may know what the issue is but want to get some suggestions first.

I recently did a complete brake upgrade:

'06 330i with OEM 335 Front Calipers, new Z4 Rotors, Rear has new Zimmerman rotors and stock calipers, and new Hawk High Performance Street 5.0 pads all around.

I had break squeak before this upgrade but had a mix-match brake pad set, stock rotors, etc. so it was time to clean things up and do a few upgrades.

Once this was complete I had ZERO squeak, everything seemed great. This lasted for 2-3 months, then the squeak returned.

Now the way the squeak works is without touching the brakes, ZERO squeak, as soon as I touch the brake lightly, squeak, but then once I push a bit harder, the squeak stops!

Here is where I THINK I may know what either I missed doing OR hopefully can still do to fix the issue: I never really broke in the pads/rotors. I did a few mild start stops but nothing really intense. I was thinking to do maybe 10 60-20 MPH stops all in a row and maybe this is what I need? This is simply a DD which goes to/from work (5 miles or less each way).

So I really dont get any high speed breaking on them ever? .

Any advise on what the issues could be?

[techwhiz]

Light braking is causing the pads to vibrate in the caliper.
Put some anti-squeal on the brake component mating surfaces (metal to metal).

[banshee28]

Originally Posted by techwhiz

Light braking is causing the pads to vibrate in the caliper.
Put some anti-squeal on the brake component mating surfaces (metal to metal).

Interestingly, I did not put any of this on during this upgrade, since I heard that "its not needed". Well maybe thats the issue, and it IS needed. Will try that once I get a chance.

Thanks.

[mefferso]

Originally Posted by techwhiz

Put some anti-squeal on the brake component mating surfaces (metal to metal).

Are you talking about the caliper pins and ears of the brake pads?

[SpartaEvolution]

Adding brake grease to the back of the pads will help, but as you mentioned you probably need to re-bed everything as well.

Bedding transfers a very thin layer of pad material onto the surface of the rotors. This increases initial friction and reduces vibration (due to like materials), and can prevent pad deposits on the rotor (often misdiagnosed as 'warped rotors') later on when you get the brakes really hot (quick stop on the freeway, or heading down a large hill).

To bed the pads and rotors together, you should get the entire brake system up to nominal operating temp by firmly pressing the brakes (without engaging ABS) and slowing from 30mph down to ~5 mph. Once up to temp, do the same thing 5-7 times from ~60 mph.

Immediately after this bedding process, drive the car on the highway for 10-15 minutes to ensure everything cools back down evenly. DO NOT hold the brake pedal when everything is still hot - if you absolutely must stop the car, use the parking brake, and try to roll the car every few seconds to get a different part of the rotor between the pads (otherwise the part of the rotor in the caliper will stay insulated between the hot pads while the rest of the rotor cools down).

The only hard part about this is finding a place you can safely drive 60mph then mash the brakes 5 times in a row! Good luck and stay safe!

Trevor
Sparta Evolution

[labrador]

Try some lube, see:
https://www.e90post.com/forums/showthread.php?t=1490582

However, I would not use Hawk pads, I do not think it meets European safety regulations ECE R90.

Zimmermann rotors are great. I would use ATE, Pagid, Jurid, or Textar pads. ATE being my first choice.

Also, when did you last bleed the brake system? Did you change these, $4.77 per axle:
https://www.rockauto.com/en/moreinfo...431850&jsn=412

[banshee28]

Yea, I may try to do some bedding of them first, and then try the grease:
Grease

This one seems good right?

Thanks...

[labrador]

That looks more like an oxygen sensor and spark plugs anti-seize, even if it says for brake system. I think it is more for "threaded fasteners". I use the Permatex version and only for oxygen sensors and spark plugs.

For brake systems I would recommend, as pointed out in the other thread I linked above, specialty lubes for brake systems:

Find these on Amazon:
http://www.ate-info.de/en/details/pr...astilube-75-ml
http://www.crcindustries.com/product...-oz-05361.html

Originally Posted by banshee28

Yea, I may try to do some bedding of them first, and then try the grease:
Grease

This one seems good right?

Thanks...

[banshee28]

Just ordered some of the CRC grease. Will try that out and do some bedding soon.