Rear brakes gone at 15k..

I get free tire rotations with my oil changes, so, they get rotated right around every 5,000 miles. But, I have my local Goodyear store do it, so, I don't really get to take a look at the pads, I can probably have them check, especially if they think they're going to potentially sell an expensive brake job out of the deal.
 
I do not recommend using the transmission to engine brake VS mechanical braking as extra strain on a transmission may lead to premature failure. Brake rotors are much cheaper than transmissions.

Except that normal engine braking does not load the transmission excessively and it doesn't cause transmission failure. But using the brakes excessively does wear them out prematurely. The transmission does not CREATE the braking force, that is done by engine compression, the transmission merely transfers the force, which is what it's designed to do.

While I don't recommend downshifting at high rpm's every time you need to slow down briefly, engine braking should be used to maintain a steady speed down long inclines. You will save a lot of wear this way.
 
Except that normal engine braking does not load the transmission excessively and it doesn't cause transmission failure. But using the brakes excessively does wear them out prematurely. The transmission does not CREATE the braking force, that is done by engine compression, the transmission merely transfers the force, which is what it's designed to do.

While I don't recommend downshifting at high rpm's every time you need to slow down briefly, engine braking should be used to maintain a steady speed down long inclines. You will save a lot of wear this way.

Well, you can recommend whatever you want, and I will recommend YOU to pay the trasmission bill for premature failures to everyone who listens to your uncredible advice.

Anytime a transmission gear needs to move from gear cog-to-gear cog, or any parts inside are moved or use excessively, the trans will wear more than a trans that does not. But, what do I know, I've only worked in a transmission shop for 5 years (rolleyes)
 
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Another thing that can cause pedal pulse is parallelism on a rotor. Sometimes the pad material can transfer to the rotor in one spot making that area on the rotor a few thousandths of an inch thicker. This causes the brake pedal to pulsate every time the rotor passes through the clamped pads in that area. The same thing can happen if a vehicle is left for long periods of time and the rotors rust more or less on the exposed surfaces verses the area that the pads are resting on.

Then there's pad materials that come into play like organic, semi metallic, and metallic pads. Organic pads make the least amount of noise and tend to have good initial bite, but they wear the fastest and are prone to fade. Metallic pads, which are made of mostly softer non ferrous metals last the longest and have the best fade resistance but they can make a lot of noise on occasion and tend to score the rotors more. Semi-metallic pads are just a compromise between the two and the ratios vary from manufacturer to manufacturer? Many auto manufacturers use pads that are more organic than not because customers are sensitive to noise and it costs manufacturers a lot of money in warranty claims when in reality there really isn't anything wrong. The typical consumer expects the braking system to be completely noise free and to last for 75,000 miles and so auto engineers are always trying to strike the best balance between fade resistance, noise free operation, and longevity.

When you think about it the braking system lives in the harshest environment. It is exposed to salt, high heat, extreme cold, goes from extreme cold to extreme heat in seconds, gets bombarded with road debris like dirt and sand, and can get completely soaked with water when the rotors are at full temperature. The braking system has to withstand all of this on a daily basis and be completely noise free, fade resistant, have both good cold weather and hot weather performance and not lose much or any braking ability over thousands of miles. This is a very tall order for what is arguably the most important system in a modern automobile. It's just a lot to ask for such an important system and it doesn't get the credit it deserves.

Yes there are many more street pad and rotor materials like ceramic but I'm trying to keep this simple. As I've said before; the factor that really makes the biggest difference in how long your brakes last is driver habits. Simply put the less you use your brakes the more they'll last.
 
These transmissions are made to be shifted manually, no? So you are saying, that we should not use it that way, because it will shorten it's life?
 
These transmissions are made to be shifted manually, no? So you are saying, that we should not use it that way, because it will shorten it's life?

Simply put, it's just like what V8toilet said, just replace the word "brakes" with "transmission"
Simply put the less you use your brakes the more they'll last.

Yes, this trans has a manual mode. Yes, you can use manual mode. But, if you use the trans to engine brake everytime or more times than what Mazda considers to be average, you are putting more wear and tear internally on all the transmission parts. If my transmission shifts 10,000 times over it's life span , and you shift 50,000 times over it's life span, with all other things being equal, which transmission do you think will have a better chance at lasting 7-10 years without a rebuild? I mentioned above I worked in a transmission shop for about 5 years. Of all the Asian cars that came in for rebuilds, Mazda, Honda and Nissan were the most popular. But, it's your car and you can drive it any way you want. I'm just giving friendly advice from a mechanic's POV.
 
Well, you can recommend whatever you want, and I will recommend YOU to pay the trasmission bill for premature failures to everyone who listens to your uncredible advice.

Anytime a transmission gear needs to move from gear cog-to-gear cog, or any parts inside are moved or use excessively, the trans will wear more than a trans that does not. But, what do I know, I've only worked in a transmission shop for 5 years (rolleyes)

Good god, I shouldn't accelerate anymore either!
 
Good god, I shouldn't accelerate anymore either!

You forgot to quote me on "But, if you use the trans to engine brake EVERYTIME OR MORE THAN what Mazda considers to be average" part. If you don't believe me, call any reputable transmission shop and ask them if your trans will need a rebuild sooner or later if you constantly downshift on every down hill you encounter to save your ($150) brakes pads and rotors. It's not rocket science folks. But, like I mentioned, drive like you want, it's your car, it's your money. Just know some facts- transmission shops exists for a reason, NO transmission is bullet proof, and transmissions costs a lot more to R& R than brake pads and rotors.

Edit: the transmission shop actually may recommend you downshift on every hill to save your brakes, as they will want your business (lol2)
 
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I've noticed that my car downshifts on its own when I'm applying the brakes going downhill, or applying the brakes firmly while driving about 40mph or higher. Are you saying that it is because Mazda wants our transmissions to wear faster so we buy a new car sooner ?

Wait until you're going down a long hill riding your brakes and boil the brake fluid. By the time your at the bottom of the hill you'll discover you have no brakes, but your transmission will be fine.

http://www.lelandwest.com/brake-fluid-comparison-chart.cfm
 
I've noticed that my car downshifts on its own when I'm applying the brakes going downhill, or applying the brakes firmly while driving about 40mph or higher. Are you saying that it is because Mazda wants our transmissions to wear faster so we buy a new car sooner ?

Wait until you're going down a long hill riding your brakes and boil the brake fluid. By the time your at the bottom of the hill you'll discover you have no brakes, but your transmission will be fine.

http://www.lelandwest.com/brake-fluid-comparison-chart.cfm

Sure, the trans downshifts automatically, but not every time. I am referring to excessive downshifting just to save brake pads and rotors. Me personally, on a long hill, I keep my trans in 6th, as there is enough engine braking in 6th without having to go into 5th or 4th, then use my brakes when needed. If your brake fluid is boiling, then you have too much water in your brake fluid and it is beyond brake fluid flushing intervals, which is bad on internal brake components like expensive ABS motors and actuators. Or, do you think brake fluid doesn't go bad or need changing? Again, signs of owner negligence.
 
Unless you live on a rollercoaster, I don't see how engine breaking can significantly decrease transmission life. I mean, your tranny shifts six times to accelerate and another six times to decelerate. On a typical trip you might encounter more than 10 lights and stops. That's easily another 100 shifts. If you encounter stop and go traffic (as we almost all do) you can add another 50-100 shifts. So a typical trip to work might be 150-200 shifts. So what if I add 4-8 shifts because a have a couple steep hills on the way. That's like a 2 to 4% increase in transmission use, hardly significant...

The purpose of a transmission is to transfer power between the motor and the road and vice versa. Asking us not to do that is like a asking us to wear our shoes on our heads instead of our feet to prevent wearing them out.

That said, I'm no mechanic so what do I know...
 
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Unless you live on a rollercoaster, I don't see how engine breaking can significantly decrease transmission life. I mean, your tranny shifts six times to accelerate and another six times to decelerate. On a typical trip you might encounter more than 10 lights and stops. That's easily another 100 shifts. If you encounter stop and go traffic (as we almost all do) you can add another 50-100 shifts. So a typical trip to work might be 150-200 shifts. So what if I add 4-8 shifts because a have a couple steep hills on the way. That's like a 2 to 4% increase in transmission use, hardly significant...
Let's use your example and say your hills are in your daily routine to work. And say you will drive your car there for 5 years. That equates to 7,000-14,000 extra shifts in that time, using 350 days more or less to account for off days or lazy days. This does not include the over due fluid change that most drivers neglect to do. So, thats 7k-14k more than if you just use the brakes and let the trans do it's work on it's own. Still insignificant? Then prove it. I can prove that Mazda transmissions can and have gone bad, most with normal driving (no extra downshifting for hills). PM me and I'll let you speak to the master transmission shop owner I worked for.
 
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Let's use your example and say your hills are in your daily routine to work. And say you will drive your car there for 5 years. That equates to 7,000-14,000 extra shifts in that time, using 350 days more or less to account for off days or lazy days.. This does not include the over due fluid change that most drivers neglect to do. So, thats 7k-14k more than if you just use the brakes and let the trans do it's work on it's own. Still insignificant? Then prove it. I can prove that Mazda transmissions can and have gone bad. PM me and I'll let you speak to the master transmission shop owner I worked for.
Extend my example to 10 years, heck, extend it to 100 years if you want to. The numbers still remain 2-4% increase in transmission use. And yes, that is not significant. Do Mazda transmissions fail? Sure they do. Is it because of engine braking? Quite probably not. On a 10 year life span you tranny might fail a couple months earlier, that's what 2-4% represents, but it would have failed anyway.
 
Extend my example to 10 years, heck, extend it to 100 years if you want to. The numbers still remain 2-4% increase in transmission use. And yes, that is not significant. Do Mazda transmissions fail? Sure they do. Is it because of engine braking? Quite probably not. On a 10 year life span you tranny might fail a couple months earlier, that's what 2-4% represents, but it would have failed anyway.
I'm sorry, but I don't feel like your numbers equal anything that consistent in the real world. In other words, there won't necessarily be 2-4% failures out of all transmissions installed in a car. And a trans may go out 2 months early, or may be 5 years early. There is an existing post on this forum of a trans dying at less than 500 miles. I'm not saying it died due to extra shifting, but just an example of early failure. And can you prove some premature failure ISN'T From engine braking? And even though your number of 2%-4% sound insignificant, 10/100 years example still equal 14,000-140,00 extra shifts. That's a significant amount of UNNEEDED EXTRA shifts! Then let's times that by 2-3x because most owners never change their fluids or change it too late. Negligence plays an significant role in premature failure along with the thousands of parts inside a transmission moving 140,000 more times. Why ask a $4000+ transmission to do all of this when a perfectly modern 4 wheel disc braking system (which costs less than $200 to replace with proper maintenence) can do it? Folks, we have brakes! Let them do their job! (lol2).
 
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If you live in a mountainous wet area like Washington state, Oregon... your brake fluid can degrade very quickly, add to that the hilly environment and you have opened yourself up to disaster even if you change your brake fluid regularly. A 2% water content can lower the boiling point 200 degrees, and that 2% can occur much before you need to change pads.

Yes, it may be 14000 more shifts, but that is still 4% more shifts over the 5 years. So instead of my transmission lasting the 150K miles I expect it lasts maybe 4% less (144000 miles). I'd be willing to bet the vast majority of transmission repairs are more related to lack of maintenance or poor engineering like GM's shift solenoids, or their non-hardened 4th gear, Honda's torque convertor, even the CX-5 valve bodies. I doubt it is because the owner regularly downshifted for steep hills. If your theory is that it downshifting significantly leads to premature failure, all the transmission shops in the plains states should move to mountainous areas because they'll do much better business.
 
If they don't maintain their transmission they won't maintain their brakes either. At least Mazda is trying to say their transmission is "maintenance free".
 
I'm sorry, but I don't feel like your numbers equal anything that consistent in the real world. In other words, there won't necessarily be 2-4% failures out of all transmissions installed in a car? And a trans may go out 2 months early, or may be 5 years early. There is an existing post on this forum of a trans dying at less than 500 miles. I'm not saying it died due to extra shifting, but just an example of early failure. And can you prove some premature failure ISN'T From engine braking? And even though your number of 2%-4% sound insignificant, 10/100 years example still equal 14,000-140,00 extra shifts. That's a significant amount of UNNEEDED EXTRA shifts! Then let's times that by 2-3x because most owners never change their fluids or change it too late. Negligence plays an significant role in premature failure along with the thousands of parts inside a transmission moving 140,000 more times. Why ask a $4000+ transmission to do all of this when a perfectly modern 4 wheel disc braking system (which costs less than $200 to replace with proper maintenence) can do it? Folks, we have brakes! Let them do their job! (lol2).

Since you seem inclined to waving credentials around Skorpio, I'm a physicist. Physicist are basically mathematicians applying math to solve real world problems. It's my job to determine if numbers are significant or not in the real world. You are a mechanic, and from your other posts on mechanics you look like a realy good one. So if you have any mechanical arguments to why engine breaking is not good for a transmission, be my guest. But leave the numbers to me. And yes, if we assume that my example is representative of the average driving scenario, my numbers prove within reasonable doubt that the vast majority of premature (premature being significantly sooner than average) transmission failures are not due to engine breaking. Unless you have mechanical arguments to add to my example that I am unaware of that is, which would make my example unrepresentative.

There, we've exchanged credentials on a forum, I just hate having to do that...
 
Sorry, I wasn't questioning your math and numbers. Only how accurate they are in the real world. I'm not trying to brag about what credentials I have, it's just that we are in a car forum, on the internet, were many speak like they have on hands experience with what they're talking about, when in truth it's what it is only read on the internet. And what they read on the internet must be true, no?! I have no personal proof of actual percentage numbers. Like you said, I am a car guy, not a math guy. But we ARE on a car forum. And thanks for the accolade. I can only go by how many cars I've seen from personal experience go into and out of all the shops and dealerships I've worked in. And through word of mouth from local car clubs, organizations, and races. I've been into cars, trucks, motorcycles since I first drove a motorcycle when I was 9. Been driving cars since 11. Been working on cars with my dad since 11 also. Oops, I'm slipping out credentials again. Anyways, I have a lot of hands on experience. About the only thing I've not delved on is paint and body. But, I've never calculated car failure in numbers, only "wow, I notice there's a bunch more Mazda transmissions in this shop than Fords and Toyotas, but not many Chevrolets" (that last "Chevy" part is a joke btw). Over the years, I've just calculated in my head, some brands always stick out more than others. As far as online numbers, www.truedelta.com lists 7.5% of CX-9 owners have reported transmission repairs. Yes, it's not a CX-5, but our model has only been out a few years. As far as mechanical arguments to add, without going into a long list of transmission parts, I will just say that it contains many gears, valves, passages that can be affected by wear and tear. But we are getting a little off subject. My point is that transmissions costs so much more time and money than brakes. Assuming you have more sense than money, why risk pushing it? I apologize by having you be uncomfortable on this forum, unless that was a joke, too ;)
 
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You must see a lot of Honda's in your shop. http://automobiles.honda.com/accord-sedan/performance.aspx

The Grade Logic Control system differs from other computer-controlled shift programming because it can detect driving situations and then set appropriate shift points for the car. It helps your Accord avoid gear hunting on climbs and descents, and it downshifts for added engine braking when needed.

All cars downshift on some hills, that wasn't in question. It's the unneeded extra "playing" around with the trans that is.
 
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