Hi, I have always wondered if the mechanics just automatically say you need new rotors even if you don't. How can I tell if I really need them? Do they have to be totally smooth, or if they're a bit grooved is that OK? Would you just lose a small percentage of braking power or a lot? I'd like to know before they see me coming. The car is a '98 Accord LX. Thanks for any info.

 

use a micrometer to measure rotors thickness and verify if it's in spec or not. A shop manual will list the minimum recommended rotor thickness.... i didn't find it in a search on the site.

 

Minimum thickness is usually stamped on the rotor itself, but sometimes hard to see with corrosion.

 

To know for sure, you would need to measure the rotor thickness as stated above.
To answer your question though, in my past experiences: (*edit*) some might. Especially in this economy, (*edit*) some shops and mechanics are going to tell you you need things you really don't need. I don't trust (*edit*) certain shops (*edit*) in my area due to past bad experiences. Hence why I became a member of this site. However, you won't know for sure unless you measure the thickness yourself.

FYI - on your car, brake pad and rotor replacement is super easy to DIY with simple hand tools - or at least it has been for me in the past anyway

 

no offense my friend but your statement is way ,way off..you are sending a total negative message about us mechanics that make an honest living .......just because you had a few bad experiences you cannot say that about all shops., few bad apples do not make the whole bushel rotten ,,,, there are a lot of honest mechanics and shops around ,, bad or good economy,,

When people make a comment about all shop being crooks it rubs me the wrong way......is all insurance agents crooks, all salesperson? electronic repair shops? plumbers? roofers? etc etc.. does it mean that if a person has a bad experience with a particular professional that all those in his ( her ) profession are not to be trusted??

if you feel like that you are going to be ripped off even before you go to a shop,, you might as well do all the work yourself , buy books and all the tools needed ..

to answer the question with the rotors......are you having any vibration when braking ?? rotors grooved? hot spots??

when measuring the rotors and they are above specs and could be machined, it also depends are much needs to be machined off to make rotors smooth .if rotors are not smooth could cause noise when braking ( growling, squealing ) . rotors could measure ok before machining them but could still be below specs after being resurfaced ,,thus should be replaced..

 

I sincerely apologize I offended you DH.
I did not intend to refer to "all shops" by any means. Now that I re-read my message I see I really did a bad job writing it. I'm going to try to edit it to reflect what I really meant to say. I hope you will accept my apology. I was way out of line.
I myself have a local Honda Certified Shop where I take my car if there is something I cannot do on my own. I also have a mechanic in my home town that I trust as if he was part of my family. There are plenty of honest shops out there.

The bottom line is: you have to be able to tell if you can trust the shop is shooting you straight or not. If you don't trust them, ask them what your rotor thickness is. They shouldn't have a problem showing you, on your car, why you need new rotors. There was an oil change place I used to use before I started changing my own oil that would physically show you what problems they found on your car. If they said your brake pads were almost worn out, they would show you.