2016 CX5 GT Needs new pads

I decided to get another opinion on the wear on my brakes, so today went to an independent tire/brake specialist. They took my wheels off and showed me the wear on the pads. Instead of the 3mmm(~1/8 in) remaining on all pads as reported by Mazda, the brake guy today showed me that my front inner pads(piston side) were considerably more worn than the outer pads, 3mm vs 7 mm left on the outer pads. So over twice as much pad left on the outer front pads as compared to the inners!!!Now the rear pads had almost 5mm left on the outers as compared to 4mm left on the inner pads. So the rears showed quite similar wear on both inners and outers. SO, what is going on with the front pads!!! There wasn't any rust on the clips as they were still well lubed. I suspect the caliper pins would still be well lubed as well. Does anyone know why the inner front pads would wear so much. I read on another Forum that the outers usually wear faster than the inners. DEFINITELY the opposite in my case. Both the front and rear rotors showed very little wear in my opinion yet the brake guy said that as a matter of course these days they usually replace the rotors when they replace pads.
 
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the brake guy said that as a matter of course these days they usually replace the rotors when they replace pads.

Yes, many of them say that...

But why? Is there actually a good reason??

I heard someone say thta the rotors as much thinner??

But even then, if they are still in good condition, whta is the complusion to replace them every time the pads are done?? We used to replace several sets of pads in cars years ago without replacing discs.....
 
I have never replaced rotors that are in good condition. I see no problem in taking a 0.010 skin cut to clean up some minor scrapes. Ed
 
Yes, many of them say that...

But why? Is there actually a good reason??

I heard someone say thta the rotors as much thinner??

But even then, if they are still in good condition, whta is the complusion to replace them every time the pads are done?? We used to replace several sets of pads in cars years ago without replacing discs.....

The rotors get thinner upon use, and when it comes time for pad replacement, the rotor thickness can be gauged and inspected to see if the rotor can be "turned" or re-machined on a lathe. There are normal brake lathes, and also there are "ON CAR" brake lathes where the rotor is machined while still bolted to the vehicle. The time and labor for a suspect rotor to be removed from the car and turned is sometimes comparable to the cost of a brand new rotor. Repair shops hate having customer comebacks from brake jobs, so they will lean towards recommendation of REPLACING the rotors instead of resurfacing them.
 
I went back to my dealer 2 days ago to talk to them again about what I considered premature wear at (~25,500 miles) on both my fronts and rears, but particularly my inner fronts. They looked up my service record to note that I came in for the $100 brake service at the end of my first year (~9,500 miles) but did not come in at the end of my second year of ownership, and that probably caused the problem of a potentially ceasing caliper. They serviced my calipers at my recent service(~25.500 miles) but did not mention that the calipers were ceasing. So, how could they cease last year (and prematurely wear my inner front pads) but not still be ceasing up now?? More importantly, if they were so insistent that I get my brakes serviced at the end of the 1st year why did they NOT even ask me to have them serviced at the end of the 2nd year?? The service manager sure seemed to be alluding that it was my fault for not bringing it in for brake servicing at the end of year 2. Now as I have previously mentioned, in the 5 vehicles that I have previously owned, I never once had ceasing calipers or premature brake wear, and I had kept some vehicles at least 10 years. It's looking more like poor quality Mazda oem brake pads and/or calipers!!
 
There is absolutely nothing in the service schedule that says the brakes must be serviced every year.
 
I went back to my dealer 2 days ago to talk to them again about what I considered premature wear at (~25,500 miles) on both my fronts and rears, but particularly my inner fronts.
Like Anchorman said, there is absolutely nothing in the maintenance schedule that says the brakes must be serviced yearly! Your dealer was trying to rip you off by forcing you with unwarranted brake job. Had they really done a proper re-lub job on caliper pins at 9,500 miles, you shouldn't have issues right now! Your Mazda dealer definitely is not helping you and it's time to contact Customer Relations Centre of Mazda Canada Inc. at 1-800-263-4680 and file a complaint. I believe your 2014 CX-5 is out of new car warranty hence anything Mazda Canada is willing to help would be a gesture of goodwill.
 
I just read on another forum that if silicone grease is not used on the sliders it will cause the small rubber boot seals to swell (as petroleum based moly greases which are to be used on the clips and backs/ends of the pads only is NOT compatible with rubber) and will turn the pin-caliper into a piston-caliper arrangement, so when the calipers heat up the trapped air inside the boots will push on the pin and gently press one of the pads on to the rotor. Over time one of the pads will subsequently wear more than the other. Now this sounds exactly what may have happened to me as my front inner pads are worn WAY more than the outers (2mm vs 7mm). Could the guy at the Mazda dealer who serviced my brakes at 15,000 km be so stupid as to use moly based brake grease on my caliper sliders instead of silicone grease. I'm starting to think so.
 
It's a complete fairy tale. If the guide pins are sliding freely, the caliper will centralise itself. It works on the basic principle that for every force there is an equal and opposite force. IF, and only IF the guide pin boots were able to create enough air pressure to apply pressure (and the notion that it could is absolutely ridiculous) then the piston side would respond by following the fixed side and in any case, that would wear the outer pad. If the inner pad is wearing prematurely it is because the guide pins are sticking or because the outer pad isn't free to slide in the carrier. I've had all this before with dealers, they claim things aren't as they should be but I spent 17 years testing and developing brakes so my dad is bigger than theirs. It's no big deal to look through the wheel at the rubber boots and see if they are distorted. They would have to be inflated like balloons to do what you are suggesting in order that the tiny amount of force they can generate could do such a thing. For the price of a set of pads, you could either do it yourself of find a decent local mechanic to put some in and just chuck the old ones away. That would give you the opportunity to look at any uneven wear yourself because I had mine last week after 12 months and 12000 miles and they were all dead even at 6mm and mine was built in the same factory as yours. Brakes are easy money for dealers and usually when the service receptionist says the word, the credit comes out in a nanosecond because the prospect of not being able to stop properly strikes fear into the heart of most people and they won't question it for a second. I would take the dealer out of the equation until you find out what is going on but remember that while forums can be a useful source of information, there is many a Walter Mitty likes to come up with some form of profound bollocks. Air pressure in guide pin boots is award winning bulls***.
 
⋯ my front inner pads are worn WAY more than the outers (2mm vs 7mm). Could the guy at the Mazda dealer who serviced my brakes at 15,000 km be so stupid as to use moly based brake grease on my caliper sliders instead of silicone grease. I'm starting to think so.
Brake pads are cheap comparing to other major problems such as transmission issues. If you don't want to file a complaint to Mazda Canada Inc. about your dealer, then like Anchorman said you should take the Mazda dealer out of the equation and try to replace the pads、machine the rotors、lubricate the caliper pins with rubber grease, either DIY or by a reputable brake shop. Personally I would still contact Mazda so that they have a record about your dealer's improper behavior and by very slight chance they may decide to help you a bit.

You really don't need new rotors unless you rotor is too thin or out of spec. The minimum rotor thickness on CX-5 according to Service Manual:
Front: 26.0 mm / 1.02 in
Rear: 8.0 mm / 0.31 in

The minimum thickness after machining:
Front: 26.8 mm / 1.06 in
Rear: 8.8 mm / 0.35 in

I also agree with Anchorman that the uneven brake pad wear is caused by air pressure in caliper guide pin boots is absolutely incorrect!
 
I also agree with Anchorman that the uneven brake pad wear is caused by air pressure in caliper guide pin boots is absolutely incorrect!

I agree that the suggestion of air pressure build up in the boot did seem odd, but not being that knowledgeable about brakes I thought that maybe there was something in this possibility. Now, I have read in several places that when rebuilding/servicing the brakes that after greasing and reinserting the sliders to squeeze the boot to eliminate any air. There must be a reason for this...maybe to help keep the boot seated against the caliber, therefore keeping dirt and water out.

I definitely won't be getting the dealer to put in new pads and rotors. I'll be going to an independent garage where the bill will be half the price, and doing regular inspections myself.
 
I saw the grease and inflated rubber thing on a Miata forum but dont know enough about the problem. The problem seemed to spin around a Permatex product. Sounds like someone used the wrong kind of lubricant or something causing some rubber parts to swell in that forum. If you used petroleum based grease around certain internal rubber parts in the brake system you will get swelling. Natural rubber and petroleum based lubricants dont go well together. But most brake greases that I know of are synthetic so I cant see that as a culprit. Have to agree with Anchorman that air pockets arent causing your problem. Im on my second set of brake pads/rotors in the rear after getting almost 37k miles on them and the outboard pads are wearing more than the interiors. The reason they are wearing is because both rotors are starting to warp. Maybe thats your problem.
 
In order to wear evenly on both inside and outside pads the calipers must "float" as the outside pads are fixed to the caliper. Friction can cause the caliper not to move the outside pad into the rotor when brake pressure is applied thus putting most stopping pressure on the internal pad that is pressured directly with the caliper piston. The outside pad should be getting the opposing force into the rotor but that force may be absorbed in the caliper not floating freely. You can pull the pads and you should be able to slide/float the caliper in and out freely.
 
You can get air trapped in the main piston seal like this,

IMG_3090_zpsvtxwicjd.jpg


Most rubber around a modern brake is pretty well bomb proof. It would have to be something nasty like solvent to distort it. They are quite resistant to normal lubricant. If the inner pad really is wearing excessively, then the caliper simply isn't sliding as suggested above. It just needs stripping and cleaning as detailed here.

https://www.mazdas247.com/forum/showthread.php?123859608-Brake-caliper-clean-up
 
Since no shops that I contacted turn rotors anymore (as the price of new ones are reasonably inexpensive) I decided to replace all pads and rotors. Most franchise shops wanted up around $1000 so I found a guy who has a shop at his home (and was an automotive teacher at a local community college, so was certain he would know what he was doing). AND he charges half the hourly rate of the dealer!! My total cost, parts and labor....$458!!!

When he broke the caliper down he told me that whoever did the brake service at my Mazda dealership did a REALLY poor job. All he could see was a bit of lub on the lower clips on all wheels, and even less lube on the inner front pad clips. None on the upper clips or backs of the brake pads (where the caliper/piston come in contact with the pads). He suggested that this lack of lub on both top and bottom clips may have contributed to the inner front pads not sliding in and out freely therefore sticking to the rotor causing the premature wear that I had. In addition he said that a proper service would also include removing the clips and cleaning them before lubing them, filing off the rust from the calipers where the clips attach and lubing the slots where they attach to slow down or prevent further rusting. He even lubed the inside of the rear piston rubbers as the pistons on the rear turn in, rather than push in, and if not relubed can stick to the pistons and rip when turned in to replace the pads. He pulled out all the sliders, relubed where necessary, reinserted and `burped` the rubber boots.

BOY WAS I IMPRESSED WITH HIS WORK. He explained it all to me as he was doing the work and where many mechanics take short-cuts, so I would know what to do if I wanted to try and do it myself next time. No more brake work at the Mazda dealer for me!! And since my 3 year bumper to bumper warranty is now up, any none drive-train work I will DEFINITELY be taking to my new `backyard` mechanic.
 
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Since no shops that I contacted turn rotors anymore (as the price of new ones are reasonably inexpensive) I decided to replace all pads and rotors. Most franchise shops wanted up around $1000 so I found a guy who has a shop at his home (and was an automotive teacher at a local community college, so was certain he would know what he was doing). AND he charges half the hourly rate of the dealer!! My total cost, parts and labor....$458!!!

When he broke the caliper down he told me that whoever did the brake service at my Mazda dealership did a REALLY poor job. All he could see was a bit of lub on the lower clips on all wheels, and even less lube on the inner front pad clips. None on the upper clips or backs of the brake pads (where the caliper/piston come in contact with the pads). He suggested that this lack of lub on both top and bottom clips may have contributed to the inner front pads not sliding in and out freely therefore sticking to the rotor causing the premature wear that I had. In addition he said that a proper service would also include removing the clips and cleaning them before lubing them, filing off the rust from the calipers where the clips attach and lubing the slots where they attach to slow down or prevent further rusting. He even lubed the inside of the rear piston rubbers as the pistons on the rear turn in, rather than push in, and if not relubed can stick to the pistons and rip when turned in to replace the pads. He pulled out all the sliders, relubed where necessary, reinserted and `burped` the rubber boots.

BOY WAS I IMPRESSED WITH HIS WORK. He explained it all to me as he was doing the work and where many mechanics take short-cuts, so I would know what to do if I wanted to try and do it myself next time. No more brake work at the Mazda dealer for me!! And since my 3 year bumper to bumper warranty is now up, any none drive-train work I will DEFINITELY be taking to my new `backyard` mechanic.

A good, trustworthy mechanic is worth its weight in gold.
 
Since no shops that I contacted turn rotors anymore (as the price of new ones are reasonably inexpensive) I decided to replace all pads and rotors. Most franchise shops wanted up around $1000 so I found a guy who has a shop at his home (and was an automotive teacher at a local community college, so was certain he would know what he was doing). AND he charges half the hourly rate of the dealer!! My total cost, parts and labor....$458!!!
He's an automotive teacher and he knows what he's doing. Like banjos-n-beer said, it's nice you can find a good mechanic you can trust. For us can't find a trustworthy mechanic or want DIY we can follow Anchorman's great write-up and he's doing the same thing but reuse the old pads and rotors.

Brake caliper clean up.

If I were you I'd still call Mazda Canada and file a complaint on that unnecessary annual brake job by your Mazda dealer which actually may speed up your brake problem. Tell them all the evidence the automobile teacher found about previous poor brake job and ask for the "reimbursement" with your receipt. Of course they won't pay anything for you since you didn't do the brake job at Mazda dealer, but sometimes you never know.

BTW, what kind of new rotors and brake pads did you put in?
 
BTW, what kind of new rotors and brake pads did you put in?

My pads are AGNA-Vast Ceramic Performance Plus and the rotors are Dura International uncoated. I had originally thought of getting the coated rotors but my mechanic suggested that they were a waste of money at $60+ extra for all 4 rotors when even coated rotors eventually start to rust, plus they were special order and I couldn't wait 3 more days for them to come in.
 
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I'm new to the forum and in the process of buying a 2017 cx5 gt awd. Is this problem still on going with the new cx5's or was this a problem just with 2014 models and older? The believe the 2016 and 2017 cx5s have an electronic parking brake. Maybe Mazda solved the problem with the rear brakes by making it electronic instead of a manual brake? Any thoughts?
 
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