.005 Front Rotor runout excessive?
Thread Starter
Heel & Toe
Joined: Mar 2015
Posts: 19
Likes: 0
.005 Front Rotor runout excessive?
Just bought a "new" 1998 that has a few issues.
Car has a brake pulsation that is very noticeable/annoying.
There is no pulsation when using only the rear brakes to stop (parking brake). My conclusion then is that the problem must be in the front brakes.
Both left and right front rotors have a run-out of about .005". Could that little of a runout cause a noticeable pulsation?
Front pads are worn, maybe 25-30% left.
If I buy new rotors and pads from local auto supply, the cost is about $160 - $170.
Any reason not to buy something like this from ebay. http://www.ebay.com/itm/FRONT-REAR-4-DRILLED-SLOTTED-PERFORMANCE-BRAKE-ROTORS-8-CERAMIC-PAD-ATL023185-/281034000539?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A1998%7CModel%3ACorvette&hash=item416eee889b&vxp=mtr
Or this. http://www.ebay.com/itm/FRONT-REAR-KIT-Gold-Hart-DRILLED-SLOTTED-Brake-Rotors-Ceramic-Pads-C1380-/121050745402?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A1998%7CModel%3ACorvette&hash=item1c2f2fca3a&vxp=mtr
Alittle over $200 on ebay for drilled and slotted, front and rear. A little under $200 local for standard front only.
Any ideas or comments would be appreciated.
Thanks.
Car has a brake pulsation that is very noticeable/annoying.
There is no pulsation when using only the rear brakes to stop (parking brake). My conclusion then is that the problem must be in the front brakes.
Both left and right front rotors have a run-out of about .005". Could that little of a runout cause a noticeable pulsation?
Front pads are worn, maybe 25-30% left.
If I buy new rotors and pads from local auto supply, the cost is about $160 - $170.
Any reason not to buy something like this from ebay. http://www.ebay.com/itm/FRONT-REAR-4-DRILLED-SLOTTED-PERFORMANCE-BRAKE-ROTORS-8-CERAMIC-PAD-ATL023185-/281034000539?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A1998%7CModel%3ACorvette&hash=item416eee889b&vxp=mtr
Or this. http://www.ebay.com/itm/FRONT-REAR-KIT-Gold-Hart-DRILLED-SLOTTED-Brake-Rotors-Ceramic-Pads-C1380-/121050745402?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A1998%7CModel%3ACorvette&hash=item1c2f2fca3a&vxp=mtr
Alittle over $200 on ebay for drilled and slotted, front and rear. A little under $200 local for standard front only.
Any ideas or comments would be appreciated.
Thanks.
Burning Brakes
Joined: Aug 2011
Posts: 1,071
Likes: 14
From: Odessa TX
You realize that the handbrake is not applying hydraulic pressure to the rear calipers right? It has it's own set of shoes and is essentially a drum brake setup using the inside hub of the rear rotors.
Thread Starter
Heel & Toe
Joined: Mar 2015
Posts: 19
Likes: 0
Oops. Thanks for setting me straight on that. I will check the runout on the rears tomorrow. I have not worked on parking brake on a car with rear discs before. I assumed that the parking cable somehow mechanically actuated the disc pads.
Thread Starter
Heel & Toe
Joined: Mar 2015
Posts: 19
Likes: 0
Runout on rears is .002 - .003".
I will be buying new rotors, as I don't know of anything else that could be causing the brake pulsation.
Any comments on the ebay rotors and pads I linked to. Probably OK? Probably junk?
I will be buying new rotors, as I don't know of anything else that could be causing the brake pulsation.
Any comments on the ebay rotors and pads I linked to. Probably OK? Probably junk?
Le Mans Master
Joined: Apr 2001
Posts: 5,941
Likes: 281
From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
Are you able to turn your existing rotors? You might be able to clean them up.
If you are going to buy new ones Centric makes a high carbon steel rotor that is good.
If you are going to buy new ones Centric makes a high carbon steel rotor that is good.
Team Owner
Joined: May 2001
Posts: 87,337
Likes: 1,590
From: Western NY
Just curious...when you were checking the runout, assuming you were doing it on the car, did you have 2-3 lug nuts, in place, hand tight, to secure the rotor to the hub, while you rotated it?
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Thread Starter
Heel & Toe
Joined: Mar 2015
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Instructor
Joined: May 2014
Posts: 106
Likes: 0
From: Miami FL
I just replaced my brakes two days ago. I ordered TPS motorsports slotted rotors and HAWK HPS pads. One word....WOW....I have never had a vehicle stop so hard in my life. TPS motorsports FTW. Total price for everything was $375 I believe and well worth it. They look amazing also. I ordered them with the black zinc option($10 extra) and it gives them that beautiful black finish on the parts or the rotor that the pad doesn't come in contact with. Silky smooth operation, great looks, no noise whatsoever, they bight right away, eyeballs wanna come out of your head. I know I'm saying a lot and it might sound like i work for them but I don't. lol. I'm just super happy with my purchase. One of the best parts I have done to the car. Oh and as a side not there rotors come directly from STOP-TECH so you know there high quality.
Advanced
Joined: Jul 2013
Posts: 50
Likes: 2
From: CA
chances are the rotors were fine runout wise (0.004" is the thickness of standard office copy paper) but didn't have even pad wear.
from the horse's mouth at stop tech:
http://www.stoptech.com/technical-su...nd-other-myths
from the horse's mouth at stop tech:
http://www.stoptech.com/technical-su...nd-other-myths
Cruising
Joined: Sep 2012
Posts: 10
Likes: 0
chances are the rotors were fine runout wise (0.004" is the thickness of standard office copy paper) but didn't have even pad wear.
from the horse's mouth at stop tech:
http://www.stoptech.com/technical-su...nd-other-myths
from the horse's mouth at stop tech:
http://www.stoptech.com/technical-su...nd-other-myths
Excellent information