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BRAKES QUESTION


Poorboy

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when i brake into a stop, on dry pavement, the braking feels a bit bumpy....not the road, but the tire to brake friction. anyone else experiencing this, or know what could cause it? thanks!

 

Hi Poorboy. :D We really don't have much information to go on here.

 

Type of vehicle? How many miles on it? Disc brakes front and rear, or drum brakes on rear? Do you feel it in the steering wheel? Does it seem to be coming from the front or rear of your vehicle? If you release the steering wheel and brake, can you see the steering wheel wiggle, from side to side, in time to the brake pulsation?

 

As you can see, diagnosing over the Internet is rather futile.

 

You could have a warped brake rotor/rotors. If you see the steering wheel wiggle when you brake, it could be a front rotor. If you feel it, but do not see the wheel wiggle, it could be the rear brakes. Given the limited information provided, this would seem to be the most likely cause. But that is only an educated guess.

 

The problem could also be caused by a fault in the ABS system. I assume there are no warning lights illuminated in your instrument cluster?

 

It could also be a suspension problem.

 

Essentially, you need to take it to the Dealer or a good mechanic, and have it checked. All we can do is guess.

 

Internet guess is...warped brake rotor.

 

Let us know what you find out, and good luck! :beerchug:

Edited by bbf2530
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Hi Poorboy. :D We really don't have much information to go on here.

 

Type of vehicle? How many miles on it? Disc brakes front and rear, or drum brakes on rear? Do you feel it in the steering wheel? Does it seem to be coming from the front or rear of your vehicle? If you release the steering wheel and brake, can you see the steering wheel wiggle, from side to side, in time to the brake pulsation?

 

As you can see, diagnosing over the Internet is rather futile.

 

You could have a warped brake rotor/rotors. If you see the steering wheel wiggle when you brake, it could be a front rotor. If you feel it, but do not see the wheel wiggle, it could be the rear brakes. Given the limited information provided, this would seem to be the most likely cause. But that is only an educated guess.

 

The problem could also be caused by a fault in the ABS system. I assume there are no warning lights illuminated in your instrument cluster?

 

It could also be a suspension problem.

 

Essentially, you need to take it to the Dealer or a good mechanic, and have it checked. All we can do is guess.

 

Internet guess is...warped brake rotor.

 

Let us know what you find out, and good luck! :beerchug:

Thanks. 07 SEL AWD Edge, 9.5K miles

 

yes, i feel it in the steering wheel, but can't see the steering wheel wiggle. no warning lights. not sure of kind of brakes or drums.

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Thanks. 07 SEL AWD Edge, 9.5K miles

 

yes, i feel it in the steering wheel, but can't see the steering wheel wiggle. no warning lights. not sure of kind of brakes or drums.

 

You might have glazed your front rotors and pads during break in. Ive done this on more than one set of brakes on my auto-x cars before I went to drilled and slotted rotors. Basically if you brake too hard during the break in period (before the brake pads have a chance to seat or bed properly against the rotors) it forms just that a glaze on top of the pads and rotor. Afterward when you attempt to brake the heat build up of the brake pads produces gas which believe it or not causes pockets of gas much like boiling water. These need to escape, and with no room to go anywhere it feels exactly as you describe...bumpy.

 

This still occurs (the gas formation) even with proper seating/bedding of the pads, when you make panic/emergency stops. Hence the reason they created cross drilled and slotted rotors. The holes and slots on the surface of the rotor allow this gas to escape. Next time youre in for service or an oil change have a mechanic look at it and just ask him "Do you think these pads and rotors are glazed?

 

Hope this helps a little

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What causes brake pad glazing?

 

This is straight off the bedding instructions inside of my box of brake pads for my autox car.

 

Brake pad glazing is caused when the brake pad friction material is overheated.

This results in crystallized friction material on the pad surface and the brake disc.

Typical symptoms of glazed brake pads include: Poor stopping performance, vibration or brake judder, and cracks or fissures in the brake pad material.

Pad glazing is typically caused by operating the brake pads at a temperature above the specified temperature range of the friction material or not properly following the 'Bedding-in' instructions for the brake pads. Always follow the manufacturers brake pad bedding-in instructions and use a brake pad that has a temperature range that is sufficient for its intended use.

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What causes brake pad glazing?

 

This is straight off the bedding instructions inside of my box of brake pads for my autox car.

 

Brake pad glazing is caused when the brake pad friction material is overheated.

This results in crystallized friction material on the pad surface and the brake disc.

Typical symptoms of glazed brake pads include: Poor stopping performance, vibration or brake judder, and cracks or fissures in the brake pad material.

Pad glazing is typically caused by operating the brake pads at a temperature above the specified temperature range of the friction material or not properly following the 'Bedding-in' instructions for the brake pads. Always follow the manufacturers brake pad bedding-in instructions and use a brake pad that has a temperature range that is sufficient for its intended use.

Thanks! But is glazing covered under warranty?

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Thanks! But is glazing covered under warranty?

 

Hi Poorboy. :D Unless the Dealer can attribute the problem to some sort of misuse/abuse, and if you are within the first 1 year/12,000 miles, it should be taken care of under Warranty. You are obviously under the 12,000 miles.

 

Again, make an appointment with your Dealers Service Department, bring it in, have a Service Tech ride with you while you show him what your concern is, and let them take it from there.

 

One way or another, whether we guess correctly what the problem is, or not, that is what you will need to do.

 

Hope it is something simple, and covered under Warranty.

 

Good luck! :beerchug:

Edited by bbf2530
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Hi Poorboy. :D Unless the Dealer can attribute the problem to some sort of misuse/abuse, and if you are within the first 1 year/12,000 miles, it should be taken care of under Warranty. You are obviously under the 12,000 miles.

 

Again, make an appointment with your Dealers Service Department, bring it in, have a Service Tech ride with you while you show him what your concern is, and let them take it from there.

 

One way or another, whether we guess correctly what the problem is, or not, that is what you will need to do.

 

Hope it is something simple, and covered under Warranty.

 

Good luck! :beerchug:

thanks again :)

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Since we don't know how many miles are on your vehicle or if you are the original owner, it's hard to guess what the dealership might do - depending on what they find.

 

If it is warped rotors then it is likely driver error (or at least driver caused.)

 

They may fix it under warranty or tell you it's on your dime.

 

Regardless, in the future, whenever you make a hard stop, don't hold the brake down - roll it out or put the vehicle in park and let off on the brake. Heat (up to 1400 degrees) needs to disapate evenly arount the rotor. If you sit with the pad against the rotor, and hold the heat there, you can warp the rotor and it will have to be turned to true it up again.

 

Let us know what they did.

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Thanks. 07 SEL AWD Edge, 9.5K miles

 

yes, i feel it in the steering wheel, but can't see the steering wheel wiggle. no warning lights. not sure of kind of brakes or drums.

 

Hi Grey. :D Poorboy replied to my mileage question earlier, stating that his '07 Edge has 9.5K miles.

 

In addition, even if he is not the original owner, the 3 year/36,000 mile Bumper to Bumper Warranty would still stand, along with the 1 Year/12,000 mile on the rotors.

 

That is why either way, I was trying to impress upon him that he needs to take it to the Dealer, have it looked at, and then they will let him know what the problem is, and what will be done.

 

Your brake advice is very good though.

 

Good luck! :beerchug:

Edited by bbf2530
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