Author Topic: Brake Rotors  (Read 1300 times)

BudgetSlasher

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Brake Rotors
« on: July 31, 2018, 09:03:14 PM »
Perhaps someone can tell me how much of an issue/problem the attached images are. I will readily admit brakes are a part of the car I have not often worked on, so I am not sure how concerned to be.

The two shots are of the rear rotors on my wife's car, which I am driving while she is out of town. I noticed one is smooth, like the ones on my car and her front rotors (and how I expect rotors to be) and the other is grooved enough for rust to develop and not be removed by the pads during normal use(these shot was taken immediately after driving).

I am confident that I have the skill set needed to do, or learn to do, the work needed. But, I don't have the experience needed to determine if this is within the normal range, or it it is time to replace the rotor and pads (as far as I know the rotors are original, so they have 145,000 miles on them over 11 years).

If work needs to be done, I can handle it at my own pace. Rather than learning at the state inspection in a few months and paying the gotcha inspection prices.

SuperSecretName

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Re: Brake Rotors
« Reply #1 on: August 01, 2018, 06:36:24 AM »
if the car does not shake when you press on the brake the rotors are fine.  the only way to determine if they are still within spec is to measure them.   Get some brake cleaner and see if that cleans them off.

brakes/rotors are actually pretty simple to do if you are handy.

Mgmny

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Re: Brake Rotors
« Reply #2 on: August 01, 2018, 09:33:14 AM »
If you do need to do them, and you can't get them off (as was the case with my 2006 car original rotors coming off last year) even after hours and hours of pounding, watching every youtube video trick in the book, etc. Instead of taking it to a shop and asking them to replace the rotors for you (mine was going to cost some stupid number like $450 for this), just ask them to break free the existing rotors and re-assemble everything. They charged me labor only for this, and it took them like 15 minutes because they have some type of electric rubber hammer/pounder that broke them free quickly. I paid them $27 for something that I had struggled with and swore at for probably 4 hours on my own. One of the best $27 i ever spent.

That said, supposedly most rotors should be able to be knocked off easily, but mine were a PITA.

px4shooter

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Re: Brake Rotors
« Reply #3 on: August 02, 2018, 08:24:36 AM »
Very impressive for the rotors to last that long. Rears will wear slower, due to the weight shift and design of applying more brake pressure to the front rotors.

If you are thinking they are close, I check Amazon for replacements. Rock Auto was my go to, but the markdowns on Amazon can't be beat. Sure, my 4 cylinder Honda now has a racing brake kit on there, but it was the same price as 4 rotors and a pad set. How are your pads?

I am glad we got rid of the vehicle inspections last year. They were always reasonable, but it made me stress over their determination of tire and brake wear.

Car Jack

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Re: Brake Rotors
« Reply #4 on: August 02, 2018, 10:51:01 AM »
My first question would be: "Are the calipers on one side seized?".  It's certainly possible.  Likely worth having someone qualified pull the thing apart and confirm everything works. 

Mr. Metal Mustache

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Re: Brake Rotors
« Reply #5 on: August 05, 2018, 09:35:26 PM »
They don't look too bad. When replacing pads make sure to use the same type of material (i.e. Ceramic/Semi Metallic) otherwise I would highly recommend having surface ground for proper bedding of the new pads. Typically $8-$10 a rotor. Don't forget to grease your caliper pins while everything is apart.

If you have a caliper handy you can measure the thickness of the rotor. Usually somewhere on the rotor is a minimum thickness that is stamped on the rotor.

EricEng

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Re: Brake Rotors
« Reply #6 on: August 07, 2018, 01:20:14 PM »
Streaks like that are usually caused by the pad rather than the rotor from my experience.  They look fine though.  Watch for a vibration when braking hard, that's your surest sign to replace.

magnet18

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Re: Brake Rotors
« Reply #7 on: August 09, 2018, 12:55:48 PM »
Is the car breaking normally?
If so, I'd pull the wheels off and check the pad thickness of all 8 pads.  If all 8 are the same thickness and plenty of material left, keep rolling

The only reason I've ever had to replace rotors is when they get warped by someone at the tire shop cranking the wheel back on with an air gun.  Usually something else in the breaks goes out first, like a swollen drop hose or a siezed caliper, and I end up replacing the rotors while in there

BudgetSlasher

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Re: Brake Rotors
« Reply #8 on: August 12, 2018, 01:07:43 PM »
I mentioned this matter to the DW when she got back in town and she has decided to wait a bit. Her logic is that her next service interval and state mandatory safety inspection are coming up in the next few weeks. Her car has developed a rattle when cold (that I am fairly certain is a loose exhaust heat shield, but have not located) and she wants to make sure it is not something serious before spending more money on the car. Also the safety inspection should flag the brakes if they are an issue.

If it does get flagged I will address it.

I wouldn't be concerned about those rotors. The grooves are minimal and so is the rust.
I'm actually surprised by the age/mileage. BMW/MINI rotors don't seem to last more than 35k miles/3yrs in Northeast Ohio.

I've seen that complaint a lot for BMW/Mini when doing my research online. I have the same make (Subaru) of car with 45k and I am am still on the original pads and rotors.

BigMoneyJim

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Re: Brake Rotors
« Reply #9 on: August 12, 2018, 06:06:15 PM »
Looks like at some point the pads wore down to the metal backing and scratched it up. But since there's rust and no reports from you of scraping noises I'm guessing that's not the case now.

I think the "right way" to DIY would be to remove the rotor and take it in to have it turned, if there's enough metal left. Then reassemble with new pads.

But you may be able to get away with just replacing pads more often as this surface will wear them faster. It's been 2 or 3 decades since I've done this, but I seem to recall a parts shop (which could also do the turning) recommending softer (asbestos?) brake pads if I chose to leave the rotor rough.

EricEng

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Re: Brake Rotors
« Reply #10 on: August 13, 2018, 12:05:32 PM »
Her car has developed a rattle when cold (that I am fairly certain is a loose exhaust heat shield, but have not located)
Is her car a Subaru?  My wife's Subaru has the same problem.  I located it as the heat shield in several spots on the exhaust system (fun climbing under a running vehicle pressing stuff with a glove).  Worm gear clamps tightened it down enough to remove the rattle for a few months, but it returned.  It's a design flaw in the heat shield system.  If the bolts haven't rusted in place, you could just remove it.  Sounds terrible, but doesn't hurt anything.

My wife's car had similar rust streaks on the rotor.  New pads scrapped them clear again (didn't replace because of streaks, was just time).

BudgetSlasher

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Re: Brake Rotors
« Reply #11 on: August 13, 2018, 05:38:23 PM »
Her car has developed a rattle when cold (that I am fairly certain is a loose exhaust heat shield, but have not located)
Is her car a Subaru?  My wife's Subaru has the same problem.  I located it as the heat shield in several spots on the exhaust system (fun climbing under a running vehicle pressing stuff with a glove).  Worm gear clamps tightened it down enough to remove the rattle for a few months, but it returned.  It's a design flaw in the heat shield system.  If the bolts haven't rusted in place, you could just remove it.  Sounds terrible, but doesn't hurt anything.

My wife's car had similar rust streaks on the rotor.  New pads scrapped them clear again (didn't replace because of streaks, was just time).

It is a Subaru (~07 or 08 Forester). And I have crawled under there and poked every exhaust shield I could find while it was running, but nothing seems to change the noise . . . so I haven't figured out which one to put a worm clamp on. I suspect there is another heat shield close to the exhaust manifold concealed from below by plastic and obscured from above by the rest of the engine that is the culprit. She is also worried about some creaking and won't take my word for it that it is just worn-in bushings and shock top hats.

What will happen is she'll get her safety inspection and they will tell her everything is fine (or find a burnt out bulb) and then tell her how much it will be to fix the old car creaks and she will just decide to turn the radio up and live with it. And I will eventually locate the heat shield that rattles on a day when I have the time and the engine is cold and slap a SS clamp on it.

EricEng

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Re: Brake Rotors
« Reply #12 on: August 14, 2018, 03:12:40 PM »
So, yes exact same problem.  My wife's is 09 impreza, but generation.  Her rattle in the system was just aft of the front wheels.  From what I understand, they put a metal mesh between the heatshield and the exhaust and catalytic converter.  Over time as the system expands from heat that mesh gets compressed and/or the heatshield gets stretched out.  Then it will rattle.  Subaru tech told me to just remove the heat shield for a quick and easy fix, but sadly too rusted unless I really want to saw at it.  Hope you have better luck.  I hate and am so embarrassed by that sound.

sokoloff

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Re: Brake Rotors
« Reply #13 on: August 14, 2018, 05:11:36 PM »
I donít turn rotors any more. They usually run for two sets of pads and then get replaced.

New rotors are fairly cheap now.

reverend

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Re: Brake Rotors
« Reply #14 on: August 17, 2018, 09:14:32 PM »
It doesn't look bad to me.  Look at the pads and if you have enough material left, leave them on.

Grooved rotors?  new pads will partially wear down the ridges of the grooves and also wear to match the grooves and you'll be fine.


I've had excellent luck with Centric rotors and Akebono "Euro" brake pads.  Cheap, top quality, excellent performance (make sure to bed the brakes properly!) and no dust.

My current car got new OEM pads from the dealer that sold me the car so I know how bad the dust is and can't wait for when they're worn out but since I drive so little, that will take years. :D