How do I know my rotor's need to be replaced

Well it appears I may have solved my front brake grinding issues. It seems that the new pads were just adjusting to the new rotor’s on the front, and just needed a bit of adjustment by the Goodyear Tech, said that should resolve the issue and that they saw no other problems with the front end as they did a full inspection. HOWEVER, they stated that my back brakes need replacing and that would include new rotors. I have never had a car with rotors on the back, always drums. What are signs that your rotor’s need replacement? I have no sound coming from the back in, looking at the rotors through the gaps in the hub cap the rotors don’t appear to be scratched or damaged and when I run my finger on them they are smooth. So are they just trying to stick me with new rotors or do you have to replace the rotors everytime you change out your pads.

I have no idea how old the brakes are on the back, just bought this car back in Dec, but the dealership I bought it from did a complete brake job on the front with new pads and rotors, so kinda surprised given it’s just 5 months later that the backs now are so bad that everything needs to be changed out. I would think if they were so bad back in December the dealership just would have done them at the same time as they did the front. And I can’t believe they would go to “danagerous” in just 5 months. So how can I tell if the rotors need to be replaced? Also Goodyear suggested that a full break flush ($89) be done also on the car, not sure if that is needed either and if that is a good cost.

Car: 2003 Impala LS
Miles: 105,000

This is not anywhere near the correct way to measure rotor wear, but can you see or feel a rotor wear pattern in the rotor such that there is a pronounced lip at the inside or outside edge (normally both) of the shiny part where the pads rub? Don’t touch the rotor right after driving, it will normally be hot enough to burn your finger.

It is not unusual to need rotors, even rear rotors, by 105k miles, but if the wear groove where the pads touch is only a few thousandths of an inch deep, I would drop in new pads and keep driving. If the lip is anywhere near a tenth of an inch deep, toss the rotors. Choose brake pads that are identical to the fronts if possible so the fronts and rears behave the same, hot or cold, wet or dry.

As for the adjustment done to eliminate the noise from the front, tech almost certainly just took the car out and got the brakes good and hot. There is an elaborate ‘break in’ sequence suggested by the instructions in the box with the pads. It varies slightly depending on the pad compound. Most techs will not bother to do it unless there is a complaint, which is rare.

What you need first is a description of how much pad material is left on each of the 4 rear pads. And I’m not a fan of tire chains for this kind of work, are there any good independent mechanics near you? You can check on ‘mechanics files’ above.

The rear rotors need to be replaced when; 1) they are deeply scored and can’t be machined smooth again, 2) they are too rusty around the edges for full pad contact or they are too thin right now. The rotors have a limit marked (usually on the backside) that indicates replacement if they get this thin.

I’d replace rear rotors at 105K miles if they haven’t been done before. I’d get the brake fluid flush, too. THAT should be done every 3-5 years or so to prevent internal corrosion of the brake parts. $89 seems a bit high to me.

I don’t like chains either. Their job is to UPsell, UPsell, UPsell.

They wanted $600+ to replace rear rotors/brake pads, flush the system and put “better” new pads on the front as they believed the pads on the front while brand new were not “high quality” pads and thus why it was taking them a while to “break in” to the new rotors and getting the occasioanl grinding sound.

I’d definitely find another shop. How do they know they have ‘better’ pads? And $600 is high for that amount of work.

I kindly passed on their offer, thanked them for the free check and adjustment on the front pads and will be going to my local guy right down from me who allows me to buy the parts and he just charges me labor.

Ii think you’ve made the right decision.

Personally, I replace my rotors if there’s any sign of pulsating, glazing, or scoring. Many people “turn” the rotors, which is a machining process on a lathe that cuts a thin layer of metal off creating a new and rotationally true surface, but removing metal reduces the rotors’ resistance to warping, and I’d rather just put new rotors on. They’re cheap enough.

Re: the pads, there are different pad materials with different characteristics, but IMHO none is “better” than another. Some are more prone to being noisy. He may have put “metallic” pads on, and they can take a bit longer to “seat”.

Technically, there are tools to measure the movement of the disc side-to-side, which checks for warpage (called lateral runout), and tools called micrometers to measure disc thickness and for variations in thickness (I’ve seen this condition on vented discs, common on front brakes). But if there’s any question, it’s cheaper and better to just put new discs on IMHO.

Even with nice smooth even brake wear…the THICKNESS is the key. With the rotor off the car there is a minimum measurement cast right into the steel on the back. If it were grooved , you’d measure the groove that cuts down the most , ie the thinnest part.
– one thing the all manufactures have done in recent years to lighten up the overall weight of vehicles is to make the rotors damn near minimum at the very start which is why you see SO many rotors needing replaced at the first brake job. ( if you were to lathe off any steel at all , it would be below specs. )

Checking online from the differnt parts stores, I see there is a number of different types of pads. Ranging in price from $29.00 for a pair going up. What is the best choice for my car. I know that is awful open ended, but I don’t see buying the cheapest (organic) or buying the top flight, but for a car with 105,000 miles on it that averages about 1000 miles or so a month on it in basically city driving, what is a good choice?

I would use a mid-line ceramic pad. They will be quiet, long lasting, and rotor friendly. Centric is a good mid-line brand and I also have had good luck with pads from Advance Auto and Autozone (as long as you stick with the ceramic ones).

$600 for rear rotors and pads??? On an 03 Impala??

Run away… Run away…

A pad AND rotor kit for both rear wheels from Rock Auto cost $81. Front pads would be $29 and $15 worth of brake fluid. Considering this should be less than 2 hours work you are being charged about $220 an hour labor plus tax. Run away…

+1 for @bloody_knuckles. I just threw on a set of Centric ceramics and they’re great

I’ve been using ceramics for years now very successfully. They’re quiet, stop well, wear well, and produce less dust than most OEM (organic) pads.

Get a second opinion from an independent, non-chain shop.