Brake pad and rotor replacement question

How would you know if the rotors are out of spec?

By use of a tool such as a micrometer to measure the thickness of the rotor in several areas and compare to the minimum thickness stamped or cast into the rotor. Also, the measurements would tell you if there is uneven wear or deposits on the rotor (varying thickness).

Measuring the rotors is a great way for a mechanic to find and correct problems on other people's cars that he doesn't regularly drive. Or gets to deal with super descriptive complaints such as "idunno, it just feels weird when I step on the brake pedal" from customers lol :unsure: Also, if you are in an area with corrosion issues (winter salt, ocean sea-water, etc) you could have more rapid deterioration of the rotors.

For me, I'm running around +/- 100k miles on brake pad replacement. The rotors (to me) are inexpensive enough that I'm not even gonna think about it or test or check them or take them to a shop to have them machined / resurfaced. I'm just gonna replace them. BOOM. Done. Good for another 100k miles.
 
How would you know if the rotors are out of spec?
In addition to 2 previous posts, here’s Mazda’s official inspection and repair procedure on brake rotors:

E0D17950-176C-4174-B458-54260CF76C7C.gif


Specifically on non-2.5T brake system, the minimum thickness for vented front rotor is 26.0 mm / 1.02”; solid rear rotor is 8.0 mm / 0.31”.

As HyFlyer mentioned above, the minimum thickness is stamped or cast into the rotor. What I’ve found is this number usually becomes hard to read due to the rust at the time you’re replacing the pads.
 
In addition to 2 previous posts, here’s Mazda’s official inspection and repair procedure on brake rotors:

View attachment 302047
Thanks for posting this. I can't tell you how many times I've heard people (mistakenly) state that you aren't ever supposed to turn rotors. This conclusively proves them wrong.

I've been turning rotors for decades, and there's nothing wrong with it. I'd much rather have freshly turned OEM rotors than generic parts store Chinesium rotors.
 
In addition to 2 previous posts, here’s Mazda’s official inspection and repair procedure on brake rotors:

View attachment 302047

Specifically on non-2.5T brake system, the minimum thickness for vented front rotor is 26.0 mm / 1.02”; solid rear rotor is 8.0 mm / 0.31”.

As HyFlyer mentioned above, the minimum thickness is stamped or cast into the rotor. What I’ve found is this number usually becomes hard to read due to the rust at the time you’re replacing the pads.
Thanks for this info!
 
Just my 2 cents

Surprisingly at 33k I needed a new set of rear pads
Dealer quoted me $349(just for the rear)

I decided to go with Duralast Gold (autozone) , bought front and rear pads which cost me around $100
And local shop installed them for another $100

Can't tell how many miles my new pads would last but so far I'm happy with overall quality
 
I now got my parts. What grease should I use for the brake pads plate. Would the copper anti-seize be better? or use the Sil glyde as well?
 
I use copper anti-sieze for the areas on the calipers where the ears of the pads ride as well as the backs of the pads.

For the slider pins, I use silicone paste.
 
I now got my parts. What grease should I use for the brake pads plate. Would the copper anti-seize be better? or use the Sil glyde as well?
$5

https://www.amazon.com/dp/ (commissions earned)

I used this just on the backs of the pads - pressing surfaces metal to metal. I used the grease that came with the Powerstop pads for the sliding surfaces of metal to metal.

I used silicone paste for the slider pins that have rubber/elastomer parts in contact. https://www.amazon.com/dp/ (commissions earned)

They have had absolutely zero brake noise. My OEM setup squealed from the rear at low speed when new. I took them in and they serviced them, which took care of 90%, but they still sometimes made some noise.
 
Can't emphasize enough that if you have a 2016 or later with the electric parking brake, that you have to go into maintenance mode for the rear brakes. Also. do not turn the rear caliper piston, ever.
I would also be very leery about taking it to an independent shop. They probably don't see Mazda's a whole lot, and more than likely do not know the proper way to do the rear brakes. These guys are not factory trained, and rely instead on their experience, and not a service manual.
There have been many posts on here from other members who found out the hard way that well intentioned friends and indie shops ruined the rear calipers because they thought the old tried and true way was the ticket to a quick brake job. Be careful.
 
I got all the parts and planned to start at the rear. But i can't seem to remove the caliper bolts no matter how hard I tried. Any tips? must be because it was not removed for a long time and I live in a heavy winter area.

The wrench should go up to loosen it right?
 

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Right tighty, lefty loosey is the motto when looking straight on from the front. You need to pull down on that wrench to loosen since it's from the back. Use a rubber mallet if you have one and tap the end of the wrench down to break it free.
 
I also notice the brake pads came with hardware plates. Is it recommended to replace them as well. Are those just snug fitted and easy to remove?
 

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Yes, replace them, they press off and on with your fingers. You'll always want to use copper anti-sieze on them.
 
I also notice the brake pads came with hardware plates. Is it recommended to replace them as well. Are those just snug fitted and easy to remove?
I believe Mazda OEM brake pad kit doesn’t come with anti-rattle shims and some don’t even come with them from factory. Some suggest you want to get a new set of pad retaining clips/springs but I reuse them most of time. If the aftermarket pads come with any additional hardwares, just use them.

I use rubber friendly AGS Sil-Glyde for caliper pins and some of the metal-to-metal contacts (retaining clips/springs and pads). I also use moly-type anti-rattle grease usually comes with the OEM brake pad kit (Honda but not Mazda) on the back of brake pads or between anti-rattle shims and pads.

Strangely Mazda Workshop Manual doesn’t show any usage of anti-rattle brake grease (brown Molykote 7439) on rear brakes with EPB.

Gen-1 CX-5 front brake:
FC2CB19B-FA38-436D-A8DB-EB9F27E6E48E.jpeg

D4AF30F2-C01D-44C4-9D4F-4F6A71A994C8.jpeg


Gen-1 CX-5 rear brake (without EPB):
EE51F8F5-B275-4477-87E9-35447E7C372D.jpeg

00C32EDE-2479-4F91-8A14-F9767E3F6EFE.jpeg


Gen-2 CX-5 front brake with single-piston caliper (2.5L):
ABF6D9B3-1F65-492D-867B-DBC2773B6FB6.jpeg


Gen-2 CX-5 front brake with dual-piston caliper (2.5T):
59E3C71C-C46B-450B-A72A-21863BC58F1A.jpeg


Gen-2 CX-5 rear brake with EPB:
BFFDA921-AB7A-4B81-95F4-CAA06BD2295A.jpeg
 
Yes, replace them, they press off and on with your fingers. You'll always want to use copper anti-sieze on them.
Anti-seize is for metal to metal parts contact with no relative motion while in use.

I use high temperature grease for the sliding surfaces.
 
Silicone grease on the slider pins, yes absolutely, but I've never heard of anyone using that on the calipers. Seems like it would attract too much dirt and grime.
 
Thanks for posting this. I can't tell you how many times I've heard people (mistakenly) state that you aren't ever supposed to turn rotors. This conclusively proves them wrong.

I've been turning rotors for decades, and there's nothing wrong with it. I'd much rather have freshly turned OEM rotors than generic parts store Chinesium rotors.
You did notice the part about "on the car lathe," yeah? A lot of new cars require this nowadays. I know Ford does. Looks like Mazda may as well.

My understanding is that the on-the-car lathe accounts for any runout present in the hub assembly, as well as mounting angle to the brake caliper, and is the only factory-approved method for turning rotors. From talking to techs, and from my own reading, it seems this is mostly due to a couple of reasons, the prime one being that the on-the-car lathe greatly reduces the incidence of runout in the entire assembly, reducing call-backs and warranty work due to customer complaints about shudder and vibrations.

Here are a couple of sources that explain the details better than I could, but keep in mind that both of these are from places selling brake lathes to shops:
Everything you wanted to know about On-the-Car Brake Lathes
Subaru requires the use of an on-the-car brake lathe by its dealers

I heartily agree with the position that putting new pads on old rotors is like installing piston rings without honing the cylinder. My position has been: you might get by with it, but it's a really bad practice. However, here is a source refuting that, if rotors are probably inspected and measured before reuse: Let the Chips Fly: On-Car & Off-Car Brake Rotor Service. This supports Jmaz's approach as he reported in post #13, and may cause me to re-think long-held beliefs. :)

But, if I take that position that new pads require a newly-finished rotor surface for proper, long-term operation, and if Mazda requires an on-the-car lathe for refinishing: In my mind it comes down to - which is more cost-effective? In most cases, simply buying new rotors rather than paying a shop to turn them on the car makes the most sense

Now, if you trust your machinist to properly measure and set up for a bench lathe, and if you're meticulous when remounting the rotors and torquing everything, then you're probably fine pulling the rotors and carrying them in to be turned. In practice, what I have done with my kids' Fords is replace the front rotors, which do most of the braking and where vibration is most likely to show up, and have the rear rotors bench turned by the local O'Reillys. This is probably what I'll do with the CX-5 when it his time.
 
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