[kiku007]

Originally Posted by vsrikkanth

What surprised both of us is that the disc was fine at 9k kms with the same driving style (recorded by the same Ass during 3rd service) and something went wrong in the next 3k. The ASS in Bangalore was very helpful and they were convinced that even with my driving style the disc should not have failed so early which is why they later reimbursed the cost of the discs 15 days after the replacement was done...

I did find one more owner reporting disc and brake pad issues almost every 1000kms. He is not a demanding driver like me but his reporting of the issue looks too bad to believe it to be a quality issue....

Thanks for clarifying.

Disc deteriorated in 3000 Kms and KIA reimbursed the cost of the discs. This is interesting.

A lot of emphasis is made on your driving style but I'm inclined to think there's some component issue here. Ask your friendly KIA A.S.S to visibly inspect the discs during the next service. May be it's a one off case but just to be on the safer side in may be worth while.

[vsrikkanth]

Originally Posted by kiku007

Thanks for clarifying.

Disc deteriorated in 3000 Kms and KIA reimbursed the cost of the discs. This is interesting.

A lot of emphasis is made on your driving style but I'm inclined to think there's some component issue here. Ask your friendly KIA A.S.S to visibly inspect the discs during the next service. May be it's a one off case but just to be on the safer side in may be worth while.

I ask for inspection/ pictures of the brake caliper, discs, engine oil, transmission oil, steering fluid e.t.c and their measurements every single time since I don't generally trust ASS as much... Infact this is one of the reasons, the KIA ASS was unable to refuse reimbursement given that I cited normal discs/calipers at 9k kms from their own service records sent to me... Somehow I was inclined towards paying 20k for all the brake pads since it felt like a genuine wear and tear part, more so given my demanding driving style...

[SenPai_GTi]

Originally Posted by Kosfactor

There is a lot of difference between rash driving in normal highway speeds and Carnival speed - which is much higher than what OP has quoted on his post by the way, this is a fast vehicle by all means and a lot heavier too.

Agreed, they might have failed due to fatigue, but then all vehicles are designed keeping the driving conditions and vehicle loading in mind. This may either be a minor production quality issue of one single part/batch or an extreme driving style issue(I do not know the exact speed as the post has been edited). This has nothing to do with the design/engineering quality of Kia. All vehicles are designed for working in extreme conditions.

Originally Posted by Mr.Boss

Do you mind explaining this with some facts and figures? How many such concerns were already reported?

brake-failure-issues-kia-seltos (Brake failure issues in the Kia Seltos) (I know its not about the discs but then it concerns the braking system as a whole)

Also I do not think that the company should wait for more such concerns to determine if it is indeed a quality issue or something else. After all it is a critical component of the vehicle. And by no means am I bashing the company. It is a relatively new market for Kia MPV's. It takes time to establish a good product in newer markets. Faults and niggles only increase the company's reliability over time.

[Kosfactor]

Originally Posted by SenPai_GTi

All vehicles are designed for working in extreme conditions.

I`ll give you an instance of a near death experience that someone I know had back in the days.

Octavia Mk1 was just launched, those who bought it were completely impressed by its driving dynamics, German build quality (this was before things went south after a few years). So the boys were rowdying their new skoda vehicle on the way back from Ooty through Sigur Ghat aka steep ghat and guess what they almost went off the road because the brakes had completely faded on the way down. (its not open anymore for vehicles coming down the hill for obvious reasons).

[PrasannaDhana]

Originally Posted by vsrikkanth

3. Combination of both

Definitely combination of both. I have been mental with driving not very long ago, but even for me, the disc pads always lasted 40k km and I never had to replace the brake discs before 6 digit mark on the odo.

Doesn't help with the already bad reputation that Hyundai group has, with part quality.

By the way, Kia carnival isn't really something that should be driven hard. It's a 5m van and needs to be driven with care. 200 bhp is meant to be used to move 9 passengers without strain, not to be doing top speed checks and driven like a sporty sedan.

Use engine braking along with brakes when you need to do aggressive braking. Infact, good drivers use engine braking at all possible times.

Take care!

[AdityaRai]

Originally Posted by vsrikkanth

... Somehow I was inclined towards paying 20k for all the brake pads since it felt like a genuine wear and tear part, more so given my demanding driving style...

Most of the vehicle is built of "wear and tear" components, even a strong metal chassis will lose its strength due to metal fatigue and corrosion eventually. Components are designed for "useful life", i.e, 2L km without major failures.

What seems to have happened in your case is one mishap damaging your brake discs.

If you brake hard from high speeds, and then keep your foot on the brake pedal for a long duration (common after hard braking for an emergency situation), the disc would cool down unevenly (portion covered by the pads remains hot, rest cools down) causing the discs to warp.

This is a test case that is evaluated during brake-disc design (and dictates the dia/thickness of discs), but, as I said earlier, it's designed for "useful life under usual circumstances".

My 2 cents: Don't keep your foot on a brake pedal for a second longer than necessary. It can also lead to brake failure due to fluid boiling thanks to conduction via the pads and pistons. It is best to brake gradually from speeds, unless you are setting lap times across a race track.

[Fiestaboy]

Enough is said on your driving behavior, but take those in positive side.
Since no one touched on vehicle, I would like to say something.

There is some thing called as "Target customer" when a car is designed.

In this case, for Carnival, Kia will be thinking someone like, 40+, well settled in life, looking to show the car as one of his success factor to the society, chauffer driven, priority in comfort compared to Dynamics & Handling.

Design of the car will be done considering in mind the above factors.
However, does that mean others will not like the car? - No is the answer, but the target customer (40+ professional, attending a meeting in 2nd row powered seat) will enjoy the car more than a petrolhead in 20/30+ who wants to drive the car in 1st row at triple digit speeds.
Moreover, features will also be loaded keeping those in mind. {2nd row powered seats, 2nd row infotainment controls, laptop placement provisions, 2nd row powered sliding doors}

From what I can see, Skoda Rapid, Octavia VRS segment of cars are designed keeping in mind the petrolheads & those cars will help to enjoy the drive in 1st row compared to Kia Carnival.

[sgmuser]

Originally Posted by vsrikkanth

I have to confess here that I have been quite an aggressive driver. After this disc warp incident I have become a more sedate driver to ensure I don't face this issue again.

2. Quality issues with the discs/pads and if yes, how to deal with this issue with Kia in future.

Braking is not something special for a car. It is a must. This issue, to me, is a quality issue, which Kia is not unknown for. I had this one in my Nissan X-Trail, brand new as well and it was promptly replaced free of cost by the dealer. It was a quality issue as per the workshop. Unless otherwise, we are talking talking about speeding and braking in 'insane' levels not just 'aggressive' level.

[Jeroen]

A couple of thoughts / comments on disc warping:

No, it does not happen due to metal fatigue.

The clearance between the pad and the disc is only about 0,1 so a very small gap. This does not allow for much! When the disc heats up, which it always will whilst braking the gap will be even less.

In my opinion there are a few factors, often overlooked that cause disc wrap:

- contentious accumulation of dust and mud. (Yes, hosing down your brakes now and then it actually a good idea (make sure they are cooled down)

- Sticky brakes. There can be multiple reasons for the brakes to be sticky, including the above. Sticky does not mean the wheel is stuck solid, as long as the brake pad does not get totally free and keeps touching the disc you will see considerable more wear on pads, and possibly a warped disc.

When in doubt, it pays to check the temperature of your brakes regularly. Left / right should have the very same temperature. Even very moderate sticking will cause the temperature of the brake assembly and your hub to rise quickly. You can attempt (carefully) to feel the temperature of each wheel/brake. Better yet, use an Infra red thermometer. These are notably unreliable, especially on aluminium, but we are interested more in temperature differences than in exact temperature.

- Problems with the bearings; Which means the pad and disc will touch unevenly.

The BIGGEST, most overlooked and very relevant: Incorrect tightning/torqued wheel nuts.

Over -, under -, and uneven tightening of the wheel nuts/studs/bolts can deform or distort both the brake rotors and the wheel hubs.

In practice, the plane of the clamping force that slows the vehicle down is offset from the plane of the clamping force that holds the rotor against the wheel hub. This means that every time the brakes are applied, a twisting force is generated that attempts to dislocate and or deform the brake rotor, and the only things that prevents this are the correct torque value(s) of the wheel nuts/studs/bolts, and the absence of rotor run out.

Interestingly enough; wrong sequence of tightening/torquing causes even bigger problems than over or under tightening!

I would say the likelihood of driving style causing these sort of problems is much smaller than some other problem with your brakes.

In fact; many so called warped discs are not warped at all. They have just accumulated a lot of debris from the pads. Easy to fix. This is what also happens after a very hard stop and you keep your foot on the brake. Contrary to popular belief (i.e. as everyone tells you on the Internet), it won’t cause the disc to warp. What happens is some of the brake pad material gets imprinted on the disc. It feels like the disc is warped, which in fact it is not, most likely.

As I have said so many times, when you have a problem you must diagnose the problem first. A wobbly steering wheel under braking, does not mean you have a warped disc! The only way to tell is to actually measure the disc, clean it properly and see what happens next.

I would say 75% of the discs being replaced, are actually other problems. But as with new discs also new pads are installed, the callipers are removed, cleaned and re-installed etc, so the problems tends to go away.

A very expensive way of solving brake problems.

Jeroen.

[Romeo_Mike]

Without prejudice to OP's driving habits, If a certain mass market car is capable of hitting certain speeds, then its brakes should be capable enough to bring it down from those speeds reliably. Period.

This rather looks like another value engineering project gone sideways. If Kia expect the Carnival to be driven gently to have the brakes last as long as expected, they should mention this in the brochure. I find it appalling that they denied to bear the cost of the shot discs initially.

[alphahere]

As many have already commented on the driving style, I do not want to place more comments on that. But that is the first point that comes to mind that causes excessive heat buildup in the discs. This is a heavy vehicle isn't it? It's not easy to haul a 2.5 ton equivalent mass from triple digit speeds down to 0 in a matter of seconds. All that energy has to go somewhere if not transferred to another object in front.

Also it is good practice to be always be aware of the brakes and not use them as just another piece of equipment. My personal best practice when it comes to maintaining peak performance of the brakes is like so. Never keep the pedal pressed while stationary. As soon as the vehicle stops move over to the parking brake. This helps to avoid the brake pad from fusing on to the hot rotor and later causing a shudder when brakes are applied. This phenomenon can happen on all road vehicles, not just Kia or any other brand. Having an electric parking brake is a bonus. All it takes it a push on the gas pedal when ready to move and off you go if you are already in Drive. No need to manually release the parking brake (of course this feature may be manufacturer dependant).

[ValuableRecluse]

Originally Posted by Jeroen

A very expensive way of solving brake problems.

Jeroen.

Amazing explanation! I’m feeling an intense urge to walk down to my vehicle and re-torque the wheel nuts, in the correct sequence!

Originally Posted by Romeo_Mike

Without prejudice to OP's driving habits, If a certain mass market car is capable of hitting certain speeds, then its brakes should be capable enough to bring it down from those speeds reliably. Period.

Brakes just covert kinetic energy into heat. This heat is stored in the disks primarily and left to radiate into the supporting structure as well as passing airflow.
This heat generated is cumulative.
Unless, there is an adequate cooling period between each high speed braking event the brakes will overhead, leading to fade/juddering.
I agreed with you, the manufacturer has to provide brakes, adequate enough to stop the vehicle well, from the speed it is capable of achieving. But, if there are repeated high speed stops without an adequate cooling period in between, any braking system, on any production vehicle, will eventually fail.
Years ago, I remember watching a TopGear episode, where one of the presenters was trashing a BMW M5 on a track. He had to stop after a few laps due to brake fade.

[headers]

Originally Posted by vsrikkanth

According to the ASC, the front rotors/discs were warped and all brake pads were worn out.

I have to confess here that I have been quite an aggressive driver. After this disc warp incident I have become a more sedate driver to ensure I don't face this issue again.

Were you shown the rotors / disc? Its not easy to warp them!!

Originally Posted by vsrikkanth

2. Kia ASS are clueless about this vehicle. They check with the plant, write to Kia about every problem since this vehicle is new in India.

3. Even as a 40 lac vehicle owner, we have to go through the service experience of a car maker who sells Sonet and Seltos alongside a 40 lac car. Little to no premium service experience, more so since they always assume it's the chauffeur waiting for the service, not the owner himself as is in my case.

#2 is why the rotors were replaced at KIA, they learn at our experience, especially in modern cars!!

#3 is very true in when brands try to accommodate across the spectrum!!!

Originally Posted by Jeroen

A couple of thoughts / comments on disc warping:

No, it does not happen due to metal fatigue.


The BIGGEST, most overlooked and very relevant: Incorrect tightning/torqued wheel nuts.

Over -, under -, and uneven tightening of the wheel nuts/studs/bolts can deform or distort both the brake rotors and the wheel hubs.

In practice, the plane of the clamping force that slows the vehicle down is offset from the plane of the clamping force that holds the rotor against the wheel hub. This means that every time the brakes are applied, a twisting force is generated that attempts to dislocate and or deform the brake rotor, and the only things that prevents this are the correct torque value(s) of the wheel nuts/studs/bolts, and the absence of rotor run out.

Interestingly enough; wrong sequence of tightening/torquing causes even bigger problems than over or under tightening!

I would say the likelihood of driving style causing these sort of problems is much smaller than some other problem with your brakes.

In fact; many so called warped discs are not warped at all. They have just accumulated a lot of debris from the pads. Easy to fix. This is what also happens after a very hard stop and you keep your foot on the brake. Contrary to popular belief (i.e. as everyone tells you on the Internet), it won’t cause the disc to warp. What happens is some of the brake pad material gets imprinted on the disc. It feels like the disc is warped, which in fact it is not, most likely.

As I have said so many times, when you have a problem you must diagnose the problem first. A wobbly steering wheel under braking, does not mean you have a warped disc! The only way to tell is to actually measure the disc, clean it properly and see what happens next.

I would say 75% of the discs being replaced, are actually other problems. But as with new discs also new pads are installed, the callipers are removed, cleaned and re-installed etc, so the problems tends to go away.

A very expensive way of solving brake problems.

Jeroen.

Excellent points sir, especially wrt wheel tightening sequence as well as the correctness of the job!!

[IP_Man]

Originally Posted by vsrikkanth

I have to confess here that I have been quite an aggressive driver. After this disc warp incident I have become a more sedate driver to ensure I don't face this issue again.

After purchasing such an expensive car, why you should change your driving style? That said, I don't mean you drive at dangerous speed.

I can understand issue of brake pad warn out but I can not digest disc warpage due to heat. IMO this is a quality problem.

[vsrikkanth]

Originally Posted by headers

Were you shown the rotors / disc? Its not easy to warp them!!

Excellent points sir, especially wrt wheel tightening sequence as well as the correctness of the job!!

Originally Posted by IP_Man

After purchasing such an expensive car, why you should change your driving style? That said, I don't mean you drive at dangerous speed.

I am now suspecting the heavy payload I had during those 3k kms when I had my carnival boot filled floor to roof combined with my driving style, since even at 9k kms my discs were fine when the ASS assessed them during the 3rd service.

Originally Posted by Jeroen

A couple of thoughts / comments on disc warping:

Sir, I am not sure if extraordinary payload could be the cause because I had mentioned that until 9k kms, my discs and pads were fine when they were assessed at 9k kms during the 3rd service. What happened post that is I drove about 3k kms with an extraordinary payload, we managed to fill the carnival boot with the 3rd row folded from floor to roof. In addition we also had heavy items such as traditional grinding stones bought for home use. Moreover, with all this payload, I also made a trip to Kolli hills and Yercaud - both of which are reasonably challenging ghat drives. After hearing all the comments, I am starting to suspect if the heavy payload along with the practice of regularly touching high 3-digit speeds caused the discs to fail between 9k and 12k kms on the odo. Also even though I don't have access to running water, I have started degreasing and rinsing the wheels/rims using water sprayers once in 2 weeks to remove as much dust as possible...