Giorginetto

I replaced the front brake disks and brake pads all done at Porsche with original Parts ( was thinking for Zimmerman ones but deiced to go for the originals) , when hot the brakes make this horrible squeak noise at low speeds when braking to a stop especially. I have been advised at Porsche to drive the car for a bit and that the noise will disappear ....

is that a common issue with new OE brakes ? shall i check for anything else ( dirt, springs etc ?) , any advice how to get rid of this extremely annoying noise ?

Paul Waterloo

I would think they used new anti-squeal pads.....if so, I would just drive it for a bit and see what happens.

However, I've never had brakes that started squealing and then it went away. Normally you do your brakes with a different compound, they are great at first, and then as they wear in, they start squealing at low brake pressures.

I hope your results are different. Just drive it for a while.

TonyTwoBags

Step 1: Accelerate to 100mph on a deserted road
Step 2: brake to 10mph
Step 3: repeat a few times

should get rid of new pad squeal.

Ahsai

If all the parts are genuine (like you said), I would suspect a bad installation. Usually stock pads don't create such noise even before fully bed in.

lingpoen

took it back to the shop a few times...their answer was go fast and break hard a couple of times. horrible on and off squeaking for a year, OEM pads for as 2003 4cs. Has stopped now for the most part. Mostly did it when dirty. next pads will be dustless ones, if there really is such a thing-

m

Macster

Horrible squeak is relative. Without hearing the noise it is hard to say if it the noise is really horrible or something less than horrible.

Assuming the noise is truly worthy of concern my first recommendation would be to take the car back and stress that because the brakes are a safety critical system with the level of noise the brakes are generating you have lost all enjoyment of the use of the car do to anxiety about the functioning of the brakes and insist this noise be dealt with.

Depending upon consumer protection laws in your area this can get the results you want or get you shown the door and told to never come back.

If you are up to it to really check the brakes you have to get the car safely and correctly in the air and remove the wheels.

Then you might have to remove the brake hardware and in doing so confirm the hardware is installed correctly and all hardware is present and accounted for.

You also might have to actually remove the brake pads to check their condition. These can be hard to remove if they have an anti-squeal pad "stuck" to the backing plate.

If you end up removing the pads check the friction surface of each looking for something out of the ordinary. A crack, void, signs of glazing (shiny) or localized overheating.

(I've taken a coarse file to the pads beveling the edges a bit. In at least one case -- though this has *not* been necessary with my Porsche brakes -- I've even used a coarse file edge to cut shallow grooves at a bias to the rotation of the rotor on the pad faces to help cut down on squeal. Just 3 grooves at 90 degrees to each other has proven sufficient.)

Likewise check the rotor surfaces for anything out of the ordinary. Signs of scoring, excessive heat, lack of full contact by the pads.

Have a can or several of brake cleaner -- the kind that comes in in aerosol can -- and spray down the brake pistons and their dust boots to remove any brake dust. This should have been done when the brakes were done and if you get a lot dust this is sign it wasn't done and to me would cal into the question of the quality of the brake job.

As for noise, I've had mixed results with new brakes. I can't recall with the brake jobs I've done having any squealing. But the last time I had brakes done on my Boxster, the rear brakes, the brakes emit a bit of a squeal sometimes. Not bad though and this even though I did my usual bedding in process.

(Might mention that the squealing has fallen off quite a bit and is nearly gone except when the brakes are warm and I'm using them at low speed.)

Regarding brake bedding in: I've always done a brake bedding in procedure real soon after installing new brake hardware. What I have found works for me (and my Boxster and my Turbo) is to accelerate the car up to highway/freeway speed then brake hard, short of triggering ABS. Do *not* bring the car to a stop!

But you want to really work the brakes. As soon as the car slows to a speed from which you can still accelerate reasonably quickly back up to high speed release the brake pedal and accelerate the car back up to speed and apply the brakes again. Hard. Repeat this one more time then drive the car around at moderate speeds a few minutes (err on the side of caution and give it a generous few minutes) to let the brakes shed their heat load.

When I've done the above each time I apply the brakes I can feel the brakes biting harder. After 3 times the increase in bite was below my threshold to notice the increase if there was any so I just do it 3 times now and call it good enough.

Might add that I don't bed in the brakes if they are making any noise when I first road test the car after finishing the brake job. After dropping the car back on the ground and doing a sanity check to make sure I didn't forget anything I like to drive around a bit just kind of making sure the brakes are ok.

But during this road test/shake down test you must avoid making any stops from speed. If you do if you bring the car to a stop and leave the hot new pads in contact with the rotors there can be pad material transfer to the rotors and this transfer is permanent. The result is the brakes will pulse like the rotor is "warped".

If you end up checking the brakes what you find or don't find determines your next step.

Giorginetto

thanks a lot for the detailed advice and information . Will check the brakes at Porsche Athens tomorrow as they installed them and all hardware is original and then follow a ' bedding procedure'. Porsche asked me to drop the car tomorrow morning to check the installation and once this done they suggested I brake a few times hard on the motorway ( they will give me details tomorrow once they have checked the car etc ) . Will update when i have some news

DBJoe996

It sounds like a very good plan....having the installation checked. Even experienced mechanics have been known to install a brake pad backwards now and again. Once everything has been checked, bed the pads as has been described. New rotors and brake pads need a good bedding.

JayG

100 mph is a little excessive

60 mph to 20 mph with hard braking
repeat until the brakes are fading and not really stopping you, probably around 5 times. Bake hard, but don't engage ABS

Once they are fading, drive for a bit to cool the pads and rotors down WITHOUT using the brakes. The reason for this is to not deposit a spot of pad material

That will bed the brakes and should stop any squealing. The purpose of bedding is to deposit a thin even layer of pad material on the rotor

Frankly, new street pads and rotors should not have any squeal

Giorginetto

The sqeak noise is gone . thyanks for the tips above

I also replaced the rear disks and pads at Porsche but this time there was no noise or anything. 996 has brand new brake disks and pads all round now

rockhouse66

So....what was the fix? A mechanical fix at the dealer or the "bed the brakes from high speed" fix?

Giorginetto

After 30miles or so of normal driving the squeak from the front brakes dissapeared. Most of this noise was coming from the rear brakes though as I found out but as I also replaced yesterday the rear brake disks and pads this noise dissapeared completely