jaredq22

First post, so apologies for any dead giveaways.

I recently bought a 997.1 C4 with 64k miles. During the PPI, I was told the rotors have been turned, but they and the pads have a decent amount of life left.

Once I hit the ~1,800 mile mark of my ownership, the front left brake sound like it squeaks at low speeds and not under braking. I know it is the brakes because they only make noise when I am not actively braking. Once there is some pressure on the pads, the noise goes away. It also goes away for the most part after 25-30 mph. Anything under that, and its loud and pervasive. And embarrassing.

What gives? I didnt think I needed new pads/rotors so soon. But I will replace one or both of those if this will remedy the issue. Let me know if any of you all have run into this issue before, and how you solved it.

LexVan

Brake harder. They will quiet down.

jaredq22

The noise only happens when I am not braking

LexVan

Generally our cross drilled OE brake rotors are rarely turned.

A good starting point would be a measurement on your rotor and pad thickness.

groovzilla

Also Non-OEM Brake sensors can cause squealing

jbkusa

Sometimes sand or small rocks can get lodged between the brake pad and rotor.

Petza914

Sounds like your front caliper pistons might be sticking. Are the pads in that noisy caliper more worn than the others?

Turning rotors isn't a great idea. The minimum allowed thickness is only 2mm less than the new thickness. For a rotor to have enough wear to need turning and then to turn it far enough to get rid of the surface grooves, you're likely now well below the minimum thickness. Reducing the mass of metal in the rotor reduces the heat sink and will make them warp much easier. I'd start with a proper brake job using new rotors and pads and while things are apet you can see if the noisy corner has a stuck caliper.

8x57IRS

When doing my brakes I bought the genuine damping plates for front and rear brakes. I was not sure if these plates would be absolutely necessary, but the Porsche spare-part-specialist explained that the damping plate (whith doublesided adhesive tape) provide a mechanical connection between the brake pistons and the brake pads. At least the rear. The pads lift off the brake discs when the brakes are released and reduce noise. That makes sense to me. Because of the price of these plates there could be an incentive to go without ;-)
So best thing is to a) measure thickness of rotor if still in tolerance and b) check for pads and their damping plates.

Edit: Forget about the pad-sensors, wrap them up. Check your brakes on a regular base instead.

Wayne Smith

Just a note since not everyone has a micrometer in their tool box ... our rotors have wear dimples on the outer edge beyond the through holes. If you can see the dimple you still have more life in the rotors. A mirror is needed to see the back side.

jaredq22

All helpful advice. I will check it out this weekend when I can get it up on a lift