Front brakes grinding
02-02-2015, 02:55 PM
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Front brakes grinding
I have a new to me 04 carrera with 92k miles.
When I brake hard, as I am coming to a stop, I get what sounds like grinding. Over the weekend I replaced pads rotors on the front and the back but it is still doing it.
I can feel it through the pedal and it doesnt feel good. Im no expert at ABS but it almost feels like I get it when the abs would kick in.
Anyone had a similar issue?
When I brake hard, as I am coming to a stop, I get what sounds like grinding. Over the weekend I replaced pads rotors on the front and the back but it is still doing it.
I can feel it through the pedal and it doesnt feel good. Im no expert at ABS but it almost feels like I get it when the abs would kick in.
Anyone had a similar issue?
02-02-2015, 03:19 PM
#2
Race Director
If you replaced the pads and rotors on all four corners, and you have bedded in the new pads, you're right. Something seems wrong.
If you can feel it in the pedal but not in the steering wheel, maybe it is an ABS pump issue. Any PSM/ABS/whatever lights? Do you have access to a Durametric to check for brake system faults?
One question: WHen you say "new to me" - have the brakes EVER felt different to you, or have they always felt this way? If you're just not sure if what you're feeling is correct, take it to your friendly neighborhood indie for a 2-minute test drive (which I can't imagine they'd charge you for), or see if there's another nearby RL member who wouldn't mind hopping in your car for 30 seconds. That would at least give you a "calibrated" opinion of whether what you're hearing/feeling is normal or not.
When ABS activates on my 996, it kind of feels like I'm braking on marbles - and it is a little more aggressive pedal feel than any of my other cars' ABS systems.
If you can feel it in the pedal but not in the steering wheel, maybe it is an ABS pump issue. Any PSM/ABS/whatever lights? Do you have access to a Durametric to check for brake system faults?
One question: WHen you say "new to me" - have the brakes EVER felt different to you, or have they always felt this way? If you're just not sure if what you're feeling is correct, take it to your friendly neighborhood indie for a 2-minute test drive (which I can't imagine they'd charge you for), or see if there's another nearby RL member who wouldn't mind hopping in your car for 30 seconds. That would at least give you a "calibrated" opinion of whether what you're hearing/feeling is normal or not.
When ABS activates on my 996, it kind of feels like I'm braking on marbles - and it is a little more aggressive pedal feel than any of my other cars' ABS systems.
02-02-2015, 03:24 PM
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I see one of your other recent posts mentions vibration at speed on the road. Is that still true? Those two symptoms together might suggest a bearing that needs attention...
02-02-2015, 03:26 PM
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If you replaced the pads and rotors on all four corners, and you have bedded in the new pads, you're right. Something seems wrong.
If you can feel it in the pedal but not in the steering wheel, maybe it is an ABS pump issue. Any PSM/ABS/whatever lights? Do you have access to a Durametric to check for brake system faults?
One question: WHen you say "new to me" - have the brakes EVER felt different to you, or have they always felt this way? If you're just not sure if what you're feeling is correct, take it to your friendly neighborhood indie for a 2-minute test drive (which I can't imagine they'd charge you for), or see if there's another nearby RL member who wouldn't mind hopping in your car for 30 seconds. That would at least give you a "calibrated" opinion of whether what you're hearing/feeling is normal or not.
When ABS activates on my 996, it kind of feels like I'm braking on marbles - and it is a little more aggressive pedal feel than any of my other cars' ABS systems.
If you can feel it in the pedal but not in the steering wheel, maybe it is an ABS pump issue. Any PSM/ABS/whatever lights? Do you have access to a Durametric to check for brake system faults?
One question: WHen you say "new to me" - have the brakes EVER felt different to you, or have they always felt this way? If you're just not sure if what you're feeling is correct, take it to your friendly neighborhood indie for a 2-minute test drive (which I can't imagine they'd charge you for), or see if there's another nearby RL member who wouldn't mind hopping in your car for 30 seconds. That would at least give you a "calibrated" opinion of whether what you're hearing/feeling is normal or not.
When ABS activates on my 996, it kind of feels like I'm braking on marbles - and it is a little more aggressive pedal feel than any of my other cars' ABS systems.
Ive had the car about 3 weeks - its done it since i have had it. It doesnt happen all the time at all. Just when you are coming hard to a stop.
No lights whatsoever, I do not have access to a Durametic. Thinking about getting one though.
It feels exactly like you say, braking on marbles. However I get a grind kinda noise and you can definitely feel it in the pedal. It doesnt feel like its normal at all but I have been wrong before.
02-02-2015, 03:28 PM
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02-02-2015, 03:32 PM
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It sounds like you may just be getting into ABS frequently, then. ABS is definitely not subtle on the 996.
Have you tried a "panic" stop in a safe place (empty parking lot) to make sure you're into ABS, and if so, does it feel any different?
A Porsche tech would be able to tell in no time flat if what you're feeling is ABS and if it feels like ABS is engaging appropriately...take a six-pack with you, make a new friend.
Have you tried a "panic" stop in a safe place (empty parking lot) to make sure you're into ABS, and if so, does it feel any different?
A Porsche tech would be able to tell in no time flat if what you're feeling is ABS and if it feels like ABS is engaging appropriately...take a six-pack with you, make a new friend.
02-02-2015, 03:57 PM
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It sounds like you may just be getting into ABS frequently, then. ABS is definitely not subtle on the 996.
Have you tried a "panic" stop in a safe place (empty parking lot) to make sure you're into ABS, and if so, does it feel any different?
A Porsche tech would be able to tell in no time flat if what you're feeling is ABS and if it feels like ABS is engaging appropriately...take a six-pack with you, make a new friend.
Have you tried a "panic" stop in a safe place (empty parking lot) to make sure you're into ABS, and if so, does it feel any different?
A Porsche tech would be able to tell in no time flat if what you're feeling is ABS and if it feels like ABS is engaging appropriately...take a six-pack with you, make a new friend.
Appreciate the help
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02-02-2015, 04:00 PM
#8
Instructor
Where do you live? What pads are you using? My brakes feel/sound pretty weird when cold, so you may want to consider that if you've been dealing with the cold temps that much of the country has seen recently.
02-02-2015, 04:04 PM
#9
I can't imagine this having anything to do with it but......If you've changed the pads and rotors you might as well bleed the breaks. Can somebody with knowledge (I have none) chime in if moisture or other impurities in the fluid cause something like this?
It sure wouldn't hurt.
It sure wouldn't hurt.
02-02-2015, 04:12 PM
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Im in GA so it hasnt really been that cold.
02-02-2015, 04:18 PM
#12
Race Director
rwiii, bleeding the brake system will remove air bubbles and will also (if you are replacing the fluid) remove moisture-contaminated brake fluid.
Air in the brake lines will make the brakes spongy. Moisture in the brake fluid can flash to steam when the brakes get hot enough, resulting in the same effect (since gas compresses, pressing the brake pedal when gas is present in the brake lines has less effect than when no gas is present).
Excessive gas/steam in the brake lines would make it more difficult to apply the brakes hard enough to engage ABS, which doesn't sound like what's going on here. However, it's important to service the brake fluid at least as often as recommended by the factory maintenance schedule, ESPECIALLY if you'll be doing any driving that will get the brakes very hot.
Air in the brake lines will make the brakes spongy. Moisture in the brake fluid can flash to steam when the brakes get hot enough, resulting in the same effect (since gas compresses, pressing the brake pedal when gas is present in the brake lines has less effect than when no gas is present).
Excessive gas/steam in the brake lines would make it more difficult to apply the brakes hard enough to engage ABS, which doesn't sound like what's going on here. However, it's important to service the brake fluid at least as often as recommended by the factory maintenance schedule, ESPECIALLY if you'll be doing any driving that will get the brakes very hot.
02-02-2015, 05:29 PM
#14
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Tire/wheel setup? Are you running factory size/offset wheels? Factory size tires? All tires matched in brand and condition?
Only mentioning because the more obvious candidates have already been discussed... Changing the front/rear tire diameter ratio or having mismatched tires can cause the ABS system to kick in more frequently, if it really is the ABS that you are feeling.
Only mentioning because the more obvious candidates have already been discussed... Changing the front/rear tire diameter ratio or having mismatched tires can cause the ABS system to kick in more frequently, if it really is the ABS that you are feeling.
03-03-2015, 07:51 PM
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To revisit this, I am now getting an intermittent ABS Failure message and the noise has not got any better
It clears as soon as I restart the car.
I am going to invest in a Good scanner and see what it says, I would rather not take it in as I have never had much luck with the local mechanics and the nearest Porsche dealership is an hour away at least.
Anyone had similar symptoms. Brake Fluid is full, new pads rotors.
I thinking possibly the pump is out. Going to take a look at that first.
It clears as soon as I restart the car.
I am going to invest in a Good scanner and see what it says, I would rather not take it in as I have never had much luck with the local mechanics and the nearest Porsche dealership is an hour away at least.
Anyone had similar symptoms. Brake Fluid is full, new pads rotors.
I thinking possibly the pump is out. Going to take a look at that first.