Brake/Caliper Corrosion on 2016 CX-5

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
nice video, looks like it's a widely spread issue
I hope this guy put the EPB in Maintenance Mode as he didn’t mention it in the entire video!

And there’s a brand new TSB 04-007/20 which covers all CX-5’s from 2016 MY to 2020 with EPB.

subject: GRINDING NOISE FROM REAR BRAKES
Bulletin No.: 04-007/20
Last Issued: 10/12/2020

DESCRIPTION
Some vehicles equipped with electric parking brake (EPB) may exhibit a grinding noise from the rear brakes when braking. This may be caused by the rear brake pads not having the capability to remove the rust from the rear brake discs. The red rust accumulated on the discs is exposed to high temperatures during braking, and consequently the rust turns black. As the black rust is too hard to be removed by the brake pads, the rust progress is accelerated, resulting in the grinding noise.
To eliminate this concern, the brake pad material has been changed in order to improve the rust-removing capability.


There is an TSB with the rear brakes grinding, due to the rear brake pads not having the capability to remove the rust from the rear brake discs on CX-3,CX-5,CX-9 and Mazda6, although you mention yours is in the front, so this might not apply, but good to check.
 
:
2018 AWD GT Premium Red/Black
and another one, this issue is becoming viral
The grease all over the rotor and brake pads was making me crazy. Even used the coated rotors that aren't oiled. I wasn't even going to say anything about putting anti seize on the lug studs. Also too much torque on the Caliper bracket and caliper bolts. Using the breaker bar and leaning on it.

But did appreciate stepping through the service mode, and it was well filmed and to the point. I like the video, but would be unhappy if that was my car, and hope other people who watch it know what they are doing.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
The grease all over the rotor and brake pads was making me crazy. Even used the coated rotors that aren't oiled. I wasn't even going to say anything about putting anti seize on the lug studs. Also too much torque on the Caliper bracket and caliper bolts. Using the breaker bar and leaning on it.
I can understand why the guy was putting grease and anti-seize compound all over, considering all the rust I can see on a fairly new gen-2 CX-5!
 
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2016 cx5
And there’s a brand new TSB 04-007/20 which covers all CX-5’s from 2016 MY to 2020 with EPB.

Does it mention new part number for the brake pads?
Was it an issue with Mazda pads or all compatible pads?
If it's with all compatible pads, are they going to be updated as well?
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Does it mention new part number for the brake pads?
Was it an issue with Mazda pads or all compatible pads?
If it's with all compatible pads, are they going to be updated as well?
Click the upper arrow next to the poster name Hawke at the beginning of his post which I enclosed in my post, it’ll take you to his original post with his TSB document attached. Yes the TSB does list the part number for new harder rear disk pads, although the original pads seem still available for sale. I believe this’s only the problem on OEM disk pads, at least for rear, for those areas with rust problem due to road salt.
 
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2016 cx5
After losing trust in my dealer there's no way I'm giving them $350 every 6k miles for pads replacement, so had to learn how to replace pads myself. With service mode and without greasing the rotors, but without resurfacing as well. My cost was $50 for the parts + less than an hour of my time vs dealer's $350

The ones I took out were pretty miserable, compared to the front near new ones that are the same age.

The wear is critical and uneven, will post pictures tomorrow.
 
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2016 cx5
Yes the TSB does list the part number for new harder rear disk pads, although the original pads seem still available for sale. I believe this’s only the problem on OEM disk pads, at least for rear, for those areas with rust problem due to road salt.

I wonder if uneven wear and noise are two different issues. There's no way pads replacement can fix uneven wear issue, can it?

Also, interestingly, after I put new pads (along with hardware) on not as new rotors the noise became more quiet but still there is some. I suspect it's rusted disk edges hitting the new hardware.

I got Duralast Gold Ceramic Brake Pads DG1846. I failed to understand what material the new ones KBY6-26-48Z are made from. Is there hope that Duralast ceramic are going to kill the rust and my rear brakes will turn silent?
 
:
Ottawa, Ontario
:
17 Mazda 6 GT
I hope this guy put the EPB in Maintenance Mode as he didn’t mention it in the entire video!
This is all too common on youtube.
Most of those posters are not trained mechanics. They're weekend warriors posting dubious procedures.
I'd take everything they do with a huge grain of salt.
I've watched more than one rear brake job on Mazdas wth EPB where nothing was mentioned about Maintenance Mode.
It's very misleading and dangerous for anyone following their procedures.
If you ruin a caliper, can you sue the guy that posted the youtube video? Probably not....
 
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2017 Mazda 6 Sport
This is why I keep saying here that the best thing to do for your brakes is to clean and relube the caliper slide pins once a year
 
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2016 cx5
This is what I took out
20201126_105808.jpg

This is my first ever experience taking brake pads out, so I'm really interested in understanding if a) this wear on 13k pads and b) inside pads wear 3x vs outer ones is an indication of a defect or it might be normal? Common sense tells me it's not normal, what could explain that?

These explanations don't apply:
- vehicle is not driven "enough" and rust eats the brakes (there's no such thing as enough driving, and how come front brakes are immune to rust)
- you live in the city - local driving means extra wear (I keep car just to go out of town)
- SUVs brake with rear more to avoid nose dive (I believe that's total ***)
- rear pads extra wear is normal for AWD (does not apply as I have a front wheel drive car)
- rear pads are thinner vs front pads - that's obviously not true

I put 400mi this weekend on my new pads without issue, a great endorsement of my pads replacement skills.
 
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yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
This is what I took out
View attachment 233336

This is my first ever experience taking brake pads out, so I'm really interested in understanding if a) this wear on 13k pads and b) inside pads wear 3x vs outer ones is an indication of a defect or it might be normal? Common sense tells me it's not normal, what could explain that?

And please don't repeat the crap my dealer keeps giving me, I'm really fed up with things like:
- vehicle is not driven "enough" and rust eats the brakes (there's no such thing as enough driving, and how come front brakes are immune to rust)
- you live in the city - local driving means extra wear (I keep car just to go out of town)
- SUVs brake with read more to avoid nose dive (I believe that's total ***)
- rear pads extra wear is normal for AWD
- rear pads are thinner vs front pads - that's obviously not true

I put 400mi this weekend on my new pads without issue, a great endorsement of my pads replacement skills.
You need a pair of new rear disk calipers based on the wear condition of inner and outer pads. In addition to uneven wear you’ll keep getting between inner and outer pads, you’ll also have possibility of rear disk locked up while you’re driving on the highway. See the 2nd scenario of pad condition in the TSB:

E74A525D-1D1E-4092-A46B-E92D9D843400.jpeg

CF8156F3-55A4-40B3-811E-8C67A3D83BB3.jpeg
 
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2016 cx5
You need a pair of new rear disk calipers
Thanks for the conclusion
Ironically *I* don't need anything as I was planning to replace the car back in summer, I'm just stuck waiting for Mazda to produce / install the recalled failed headlight unit.
 
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yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Thanks for the conclusion
Ironically *I* don't need anything as I was planning to replace the car back in summer, I'm just stuck waiting for Mazda to produce / install the recalled failed headlight unit.
I will do due diligence complaining about this issue everywhere I can to potentially save the future owner's live
If you’re not going to keep the car for long, yes “you” don’t need these calipers. ;)

A post from another thread reminds me we should report this EPB dragging problem to NHTSA and hopefully it’ll become a safety recall like those LED DRLs.
 
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