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Weird brake rotor wear pattern

Old Apr 20, 2026 | 06:32 PM
  #1  
chaosdsm's Avatar
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From: Central Florida
Weird brake rotor wear pattern

Just finally got around to inspecting the front brakes. Car has been running well & stopping well, so I haven't been overly worried about it. BUT, being new to me, I definitely want to check on as much as possible in the first 2 to 4 months. Passenger side is good, that's the side that was rebuilt after the last owner's accident, new rotor, new pads, looks like original caliper, but the driver side only has new pads.

Driver side rotor is another story.... I've never seen wear like this on a brake rotor.

It's hard to see in a picture, but if you look at the green reflections on the photo below, that's where angles have been worn into the rotor.


The wear starts at the outer edge, with ~1/4" wide flat with overall rotor thickness of ~0.828", then angles out/up for ~1/8" and another ~1/4" wide flat measures ~0.851" thick, another angle out/up & another ~1/4" wide flat measures ~0.883", and one more angle, then a smooth flat to the center that measures ~0.915 inches. So the outer inch of the rotor contact surface is well below the minimum allowed thickness, but the rest of the contact surface is still above the 0.898" minimum.

Here's an exaggerated not-to-scale drawing of what it looks like from side profile: The outermost lip sticks up between 1/32nd & 1/16th of an inch around the outside.


I also inspected the brake fluid in the reservoir. I think I mentioned how it looked like coffee before.... I used a straw to get some out & put it in a glass container, it smells like rubber, so I'm guessing the flexible brake lines are being eroded from the inside.



I inspected the rear drums last week and adjusted the parking brake, both pads on both sides have same wear pattern, about 0.2" (+/- 0.01") pad material remaining at the top of all 4 shoes, tapering evenly down to about 0.14" (+/- 0.01") pad material at the bottom of all 4 shoes. I forgot to write down the inner diameter of the drums, but they were still under the maximum diameter, I think they were both around 229mm.

So looking like a full brake replacement might be in my near future, drums & shoes, rotors & pads, all 4 brake hoses, maybe even new calipers, and possibly even the wheel cylinder pistons.
Old Apr 20, 2026 | 07:54 PM
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chaosdsm's Avatar
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On a related note: I know I can get the AC Delco brake lines no problem, but my personal preference always gravitates towards stainless steel.....

I've found a front brake hose set in braided stainless from TRQ
Amazon Amazon
for $50, but I'm not finding an HHR specific set for the rear. Summit Racing has "universal" 10 to 11 inch braided stainless steel brake hose, ranging from $12 to $40 each. They appear to have the correct thread pattern, but a slightly different end connector. Would that make any significant difference?


This is the one I'm looking at: https://www.summitracing.com/parts/cst-sbh1311 which is designed to meet or exceed FHVSS 106 standard and is 11 inches, about 1.5" longer than the stock hose.



Old Apr 20, 2026 | 08:13 PM
  #3  
greg8453's Avatar
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From: Davison MI
I think after you get the brakes fixed you might want to have your ears checked. That wheel was talking to you but you didn't hear it.
Old Apr 21, 2026 | 07:29 AM
  #4  
Oldblue's Avatar
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From: Welland,Ont Canada
That front rotor indicates to me a sticking caliper slide pin and or constricted flex hose. Time for new rotors, pads, flex hoses and calipers with hardware.

as for the rear hoses , it’s a gamble if they fit as they are universal fit.
Old Apr 21, 2026 | 08:37 PM
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fastsuv's Avatar
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From: lockport,ny
The AC Delco end connectors have that shape so they can fit into a bracket and use a clip to hold them in.

If the ends have the proper thread, they will work but you will have to come up with a different mounting system.

Steve
Old Apr 21, 2026 | 09:50 PM
  #6  
chaosdsm's Avatar
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Thanks for the replies guys! I'm fairly good at figuring ways around things.... like the universal hoses not having the groove for the bracket / clip... If nothing else, I could probably use stainless steel zip ties to secure in place!

Originally Posted by greg8453
I think after you get the brakes fixed you might want to have your ears checked. That wheel was talking to you but you didn't hear it.
Nope... just got this car 8 1/2 weeks ago, that rotor wear happened before I got it, and the dealer put new pads on the front before I even test drove the car - as mostly mentioned in my first paragraph
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