ElanMike

Going back a couple of months, I purchased some cross-driller rotors and semi-metallic pads from Brake Performance.com I also installed some Vossen wheels on Falken FK452 tires.
When I brake there is a very loud, high frequency clicking noise coming from one/some of the wheels. The Merc dealer is trying to tell me it's just the noise the air makes over the wholes on the discs i have. This makes no sense at all.
Anyone have similar issues, or any ideas what it could be?

StephenK

Did you try asking performance.com if they know of such an issue???

Benz-O-Rama

Are they just drilled, or slotted too? Is the sound only there when you hit the brake pedal, but disappears when you release the brake pedal?

If so, the dealer is probably right. I've had a similar issue with after market slotted/drilled rotors.

All the reason to stay with OEM rotors. I've learned my lesson with these cars.

ElanMike

I have contacted Brake Performance and they responded pretty quickly. My brakes are drilled only. They said that slotted can cause a noise, but that the drilled don't usually do that. I have a follow up email in to them and will see how it goes.

allenjdmb

lug bolts.
You said you installed wheels at the same time. Does it happen with OE wheels and lug bots?

ElanMike

I just got around to installing a new set of pads which PerformanceBrakes said should fix the noise. It didn't! The weather is good enough to put the roof down again but the noise from these brakes is taking away all the fun.

mkhurley

You'll be hard pressed to get rid of it, but one option we've done on motorcycles in the past when it was really bad, is to chamfer the crossdrill holes. Your hearing the very sharp trailing edge of the crossdrill hitting the brake pad, the chamfer removes that sharp edge and the noise goes away. Best to have a machine shop do it if possible, rotors are pretty hard, you'll go thru alot of countersink bits (or large drill bits) trying it at home.

Also, slots make it worse because there is a larger trailing edge, but they also clean the pad better to provide increased braking.....function over form. Crossdrilling allows built up gases to escape and provides increased cooling, the combination of both is the best option, if you wanna stop quick.

ElanMike

Each of the wholes is actually chamfered already.
Pwerformancebrake even sent me pads with chamfered lead in/out but that didn't seem to help either.
It seems to be related to the rear. Someone mentioned to me that because it is a single disc, the air in the holes heats up and expands under braking when the pad is over them, and it's this air escaping that causes the noise!
For 2007MB used solid discs at the rear vs drilled at the front. In 2008 they went to rear drilled also. I have been thinking about just replacing with 2008 rears but not sure they will fit?

sdg1871

The DA there should be fantastic. So is the track prep there. I need r compound tires for this for best times

Leester

the wheels bolts may be too long for the new rims, causing clicking sound as they roll.
You may want the jack up one side of the car and spin the wheels as see how it goes.
Cheers.