Brakes Pulsing
11-22-2016, 01:58 PM
#1
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Location: Austin, TX
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Brakes Pulsing
The brakes on my 2000 GLE started pulsing a few days after I bought the car. The left outer CV boot was split, so I thought maybe some grease had been flung on the rotor. The boot has now been replaced, and I also replaced all the brake pads (front and rear). I cleaned the front rotors with degreaser and acetone before putting everything back together. Unfortunately, none of this fixed the problem. A few days ago I replaced the outer tie rod ends, and while I was at it, I checked front rotor runout. Both sides were within about 2-3 thousandths. Anyone else seen this problem? Is it possible for glazed rotors to cause this?
11-22-2016, 04:12 PM
#4
11-22-2016, 05:06 PM
#6
I'm just saying they're warped b/c it's the only common problem with the fronts. You don't even have to drive hard for it to happen.
Also, what else is going to cause it? Even with a destroyed wheel bearing I never had pulsing or a shimmy. I think you'd see it if you had a lot of pad material stuck on them (maybe not). Get a good look at them (or take pics).
The outcome is the same, though. There's no point putting stock size back on there. If you see deposits, then try wiring it off, I guess.
6th gen BBK or bust.
Last edited by Child_uv_KoRn; 11-22-2016 at 05:18 PM.
11-22-2016, 06:52 PM
#8
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Hey just wondering is 002-003 something u can actually feel?
Is this pulsing pretty bad or what?
The hub also has it's own runout so I think it's worth rotating ur rotor so for example ur runout is 003 and on the hub it's 002. and you just match the spots where it needs to go so you have 001 on the rotor again.
I'd just get new everything and use a torque stick on my airgun.
That **** warps rotors too.
Not torquing them right but that's like after 10,000 or whatever.
Is this pulsing pretty bad or what?
The hub also has it's own runout so I think it's worth rotating ur rotor so for example ur runout is 003 and on the hub it's 002. and you just match the spots where it needs to go so you have 001 on the rotor again.
I'd just get new everything and use a torque stick on my airgun.
That **** warps rotors too.
Not torquing them right but that's like after 10,000 or whatever.
11-22-2016, 07:56 PM
#9
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I don't think you can feel .002-.003, generally speaking. Most manufacturers have a spec of .003" - .005" for rotor runout, and that generally doesn't cause a problem. This vibrates like crazy when I hit the brakes at highway speeds, and the steering wheel shimmies. Even at low speed, like 10-20 mph, it seems I can feel the brakes grab then release, grab then release, as the wheels turn. Almost like part of the disc is greased and part is normal.
Anyway, I wasn't trying to start an argument, just wanted to know if something else regarding the rotor surface could cause this. I ordered new front rotors tonight. For what they cost, it's not worth screwing around with it.
Anyway, I wasn't trying to start an argument, just wanted to know if something else regarding the rotor surface could cause this. I ordered new front rotors tonight. For what they cost, it's not worth screwing around with it.
11-22-2016, 09:39 PM
#10
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Location: California
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My original (Nissan brakes) pulsated. I had them replaced with Brembo rotors (blank) and Raybestos pads (ceramic). Within 9 months or so, they developed the same problem..
Finally, I installed PowerStop rotors and pads. I installed them myself. When I did, I measured the runout and there was no need to install shims - so the hub was fine, and it must have been so for the previous rotors as well. It has now been three years since I installed my PoweStops, and they are awesome - quiet, clean, and smooth.
I can only identify two reasons for why my last attempt worked so well:
Finally, I installed PowerStop rotors and pads. I installed them myself. When I did, I measured the runout and there was no need to install shims - so the hub was fine, and it must have been so for the previous rotors as well. It has now been three years since I installed my PoweStops, and they are awesome - quiet, clean, and smooth.
I can only identify two reasons for why my last attempt worked so well:
- For some reason, the PowerStop pads and rotors get together very well. Or, perhaps the PowerStop rotors are superior to well-known brands such Brembo (this is hard to believe, as PowerStop is just another Chinese brand).
- During the installation, I paid a lot of attention to the angle between the pad and and the rotor. In particular, I made sure that the "angle of attack" was positive: in other words, that the leading edge of the pad did not contact the rotor before the trailing edge did.
11-23-2016, 11:51 AM
#11
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I've had a lot of issues with aftermarket brake parts in the last few years. It started when I did a brake job on my wife's older model Ford Escape a couple years ago. First, it took four attempts to find rear shoes that were correctly machined. There's a pin about 1/4" diameter on the shoes that holds one of the brake levers. The pin was incorrectly machined on one or both shoes in the first three sets, so the lever wouldn't fit. I finally bought a pair from O'Reilly that worked, but within two weeks, they were grinding. I discovered there had been some sort of contaminant in the linings (both sides), and not only were the shoes ruined, they had ruined the OEM drums as well. I bought new shoes and drums from Ford (also Chinese parts), and that solved the problem.
Then there were the inexpensive rotors I put on the rear of my Ford F150. They lasted about 15K miles, by which time they were warped like crazy. To make a long story short, I now use only Bosch Quietcast rotors and EBC green pads on our current vehicles (Ford F150 and Explorer). They seem to perform at least as well as OEM, and none have had to be replaced yet. I just bought Bosch rotors for the front of my Maxima, but I think they've been discontinued. The only place I can find them (for this car) is eBay. I'm debating whether to order a set for the rear too, even though those aren't needed yet. These rotors are just extremely good for a daily driver, and I think they'll last three or four years on this car.
Then there were the inexpensive rotors I put on the rear of my Ford F150. They lasted about 15K miles, by which time they were warped like crazy. To make a long story short, I now use only Bosch Quietcast rotors and EBC green pads on our current vehicles (Ford F150 and Explorer). They seem to perform at least as well as OEM, and none have had to be replaced yet. I just bought Bosch rotors for the front of my Maxima, but I think they've been discontinued. The only place I can find them (for this car) is eBay. I'm debating whether to order a set for the rear too, even though those aren't needed yet. These rotors are just extremely good for a daily driver, and I think they'll last three or four years on this car.
11-24-2016, 06:48 AM
#12
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Join Date: Nov 2002
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When I did the stainless braided lines along with new pads/rotors at 100k miles I used the best rotors I could get at the local Napa and some Mighty ceramic brake pads from my dad's shop. I currently have 30k miles on them and they work great. At the time of the install I also cleaned up the calipers and brackets and painted them. I also made sure the caliper pins were clean and moved freely. I suspect my results are more about the pads/rotors than the other details.
11-24-2016, 11:35 AM
#14
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Not in my experience. When they are cold they feel quite aggressive, especially when paired with the braided lines and new fluid. It brakes very different than the 2004 Grand Cherokee or my wife's 2012 Outback 3.6R.
12-17-2016, 04:04 PM
#15
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Just to follow up on this problem...
I ordered new rotors as a last resort. They arrived about two weeks ago, but the weather was too crappy to do the work. I've been driving the car to work everyday, and (of course) the pulsing almost completely disappeared by the time I finally did the work today. In fact, I wouldn't have replaced them if it had been so minor all along. The last small bit of vibration did disappear after the new rotors were installed, but there's no doubt in my mind this issue wasn't about warpage. There was clearly something wrong with the surface of the old parts.
So, take this for what it's worth - if you're having a problem like this and you're tight on cash, it might be that all you need is a minor resurface to clear it up.
I ordered new rotors as a last resort. They arrived about two weeks ago, but the weather was too crappy to do the work. I've been driving the car to work everyday, and (of course) the pulsing almost completely disappeared by the time I finally did the work today. In fact, I wouldn't have replaced them if it had been so minor all along. The last small bit of vibration did disappear after the new rotors were installed, but there's no doubt in my mind this issue wasn't about warpage. There was clearly something wrong with the surface of the old parts.
So, take this for what it's worth - if you're having a problem like this and you're tight on cash, it might be that all you need is a minor resurface to clear it up.
12-18-2016, 11:53 AM
#16
The brakes on my 2000 GLE started pulsing a few days after I bought the car. The left outer CV boot was split, so I thought maybe some grease had been flung on the rotor. The boot has now been replaced, and I also replaced all the brake pads (front and rear). I cleaned the front rotors with degreaser and acetone before putting everything back together. Unfortunately, none of this fixed the problem. A few days ago I replaced the outer tie rod ends, and while I was at it, I checked front rotor runout. Both sides were within about 2-3 thousandths. Anyone else seen this problem? Is it possible for glazed rotors to cause this?
12-18-2016, 08:23 PM
#17
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Join Date: Nov 2016
Location: Austin, TX
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We'll see, I installed Bosch QuietCast rotors. They've been excellent on my Ford F150 and Explorer. I only use them with EBC pads. An upgrade to anything else is probably a waste of time and money, at least for stock GLE like mine. Too bad, looks like they've been discontinued now, not many places still have them for the fronts.
12-26-2017, 04:58 PM
#19
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Join Date: Feb 2009
Location: Columbia SC
Posts: 2,292
Don't waste your time nor money....If you have 17" or greater wheel on the car just upgrade to 2004-08 6th Gen brakes (Caliper, torque member, rotor) 00-03 brake weren't to small the machining of about 1" of material off the inboard of both Front rotors is the problem to clear the larger knuckles...11" rotors have been around working fine since 1989...
12-27-2017, 09:29 AM
#21
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Join Date: May 2017
Location: Hudson, NH
Posts: 222
I have never experienced warped rotors. Its always glazing of the rotor surface from pads, or some other road debris like oil. I experience this usually by an emergency slam on the brake, come to a full stop and hold. Like on the highway or something. Long enough for the pads to fry an image of itself on the rotor surface. Now the next time you stop, its Slip, grab, slip, grab.. That slip/grab sensation is commonly referred to as a "warped rotor".
Many are convinced of warpage after visiting the local mechanic rotor turning machine. They always show rotors as slightly warped. The assumption is a brand new rotor is perfect circle. Nope, most new rotors appear to be "warped" right out of the box as well. Turning rotors gives you a clean surface, removing that glaze spot. It also removes some of the surface, thinning the rotor. Which means less metal to dissipate heat. More distance to push the pedal because the rotor is thinner. So, the fix is short lived.
If I'm right, its a glaze spot, all you need to do is take the front rotors off, spray some brake cleaner everywhere. Wipe with Clean rag or paper towel. Use a green scruffy or if you have really fine sandpaper, use that. Spray and wipe clean one more time. Put back on. Usually the front. If problem persists do rear. 9-10 thats all you need once a year. And an excuse to clean and grease the pins.
To prevent from happening again, get better pads, and try to avoid the slam on the brakes and hold move on hot days. Creep to stops on hot days to prevent glazing the rotors.
Many are convinced of warpage after visiting the local mechanic rotor turning machine. They always show rotors as slightly warped. The assumption is a brand new rotor is perfect circle. Nope, most new rotors appear to be "warped" right out of the box as well. Turning rotors gives you a clean surface, removing that glaze spot. It also removes some of the surface, thinning the rotor. Which means less metal to dissipate heat. More distance to push the pedal because the rotor is thinner. So, the fix is short lived.
If I'm right, its a glaze spot, all you need to do is take the front rotors off, spray some brake cleaner everywhere. Wipe with Clean rag or paper towel. Use a green scruffy or if you have really fine sandpaper, use that. Spray and wipe clean one more time. Put back on. Usually the front. If problem persists do rear. 9-10 thats all you need once a year. And an excuse to clean and grease the pins.
To prevent from happening again, get better pads, and try to avoid the slam on the brakes and hold move on hot days. Creep to stops on hot days to prevent glazing the rotors.
12-27-2017, 09:47 AM
#22
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Join Date: May 2017
Location: Hudson, NH
Posts: 222
Just to follow up on this problem...
I ordered new rotors as a last resort. They arrived about two weeks ago, but the weather was too crappy to do the work. I've been driving the car to work everyday, and (of course) the pulsing almost completely disappeared by the time I finally did the work today. In fact, I wouldn't have replaced them if it had been so minor all along. The last small bit of vibration did disappear after the new rotors were installed, but there's no doubt in my mind this issue wasn't about warpage. There was clearly something wrong with the surface of the old parts.
So, take this for what it's worth - if you're having a problem like this and you're tight on cash, it might be that all you need is a minor resurface to clear it up.
I ordered new rotors as a last resort. They arrived about two weeks ago, but the weather was too crappy to do the work. I've been driving the car to work everyday, and (of course) the pulsing almost completely disappeared by the time I finally did the work today. In fact, I wouldn't have replaced them if it had been so minor all along. The last small bit of vibration did disappear after the new rotors were installed, but there's no doubt in my mind this issue wasn't about warpage. There was clearly something wrong with the surface of the old parts.
So, take this for what it's worth - if you're having a problem like this and you're tight on cash, it might be that all you need is a minor resurface to clear it up.
12-27-2017, 11:51 AM
#23
Senior Member
Join Date: Jan 2003
Location: California
Posts: 1,445
I have never experienced warped rotors. Its always glazing of the rotor surface from pads, or some other road debris like oil. I experience this usually by an emergency slam on the brake, come to a full stop and hold. Like on the highway or something. Long enough for the pads to fry an image of itself on the rotor surface. Now the next time you stop, its Slip, grab, slip, grab.. That slip/grab sensation is commonly referred to as a "warped rotor".
Many are convinced of warpage after visiting the local mechanic rotor turning machine. They always show rotors as slightly warped. The assumption is a brand new rotor is perfect circle. Nope, most new rotors appear to be "warped" right out of the box as well. Turning rotors gives you a clean surface, removing that glaze spot. It also removes some of the surface, thinning the rotor. Which means less metal to dissipate heat. More distance to push the pedal because the rotor is thinner. So, the fix is short lived.
If I'm right, its a glaze spot, all you need to do is take the front rotors off, spray some brake cleaner everywhere. Wipe with Clean rag or paper towel. Use a green scruffy or if you have really fine sandpaper, use that. Spray and wipe clean one more time. Put back on. Usually the front. If problem persists do rear. 9-10 thats all you need once a year. And an excuse to clean and grease the pins.
To prevent from happening again, get better pads, and try to avoid the slam on the brakes and hold move on hot days. Creep to stops on hot days to prevent glazing the rotors.
Many are convinced of warpage after visiting the local mechanic rotor turning machine. They always show rotors as slightly warped. The assumption is a brand new rotor is perfect circle. Nope, most new rotors appear to be "warped" right out of the box as well. Turning rotors gives you a clean surface, removing that glaze spot. It also removes some of the surface, thinning the rotor. Which means less metal to dissipate heat. More distance to push the pedal because the rotor is thinner. So, the fix is short lived.
If I'm right, its a glaze spot, all you need to do is take the front rotors off, spray some brake cleaner everywhere. Wipe with Clean rag or paper towel. Use a green scruffy or if you have really fine sandpaper, use that. Spray and wipe clean one more time. Put back on. Usually the front. If problem persists do rear. 9-10 thats all you need once a year. And an excuse to clean and grease the pins.
To prevent from happening again, get better pads, and try to avoid the slam on the brakes and hold move on hot days. Creep to stops on hot days to prevent glazing the rotors.
To avoid this problem you need to measure rotor runout on/after installation. Both of my earlier rotors (OEM, and Brembo blanks) warped and vibrated as a results (runout was like 1/16 of an inch). I replaced them with a set of PowerStops from Rockauto. I installed them myself, and took great care to install them correctly. BTW, these PowerStop sets (rotor + pads) are so inexpensive it does not make sense to grind/repair the old rotors.