[Jeroen]

Originally Posted by ChoosetoCruze

I think you may have misinterpreted what was posted in the last paragraph of the opening post.

It was mentioned that even changing the brake booster did NOT eliminate the problem. It reappeared again even with the new brake booster.

Thanks, I had read it differently, but you are correct.

Originally Posted by lapis_lazuli

the booster isn't the root cause but probably the boost enabler that's the issue perhaps.

Irrespective, when a brake booster / enabler fail the brakes should still work normally. They will require considerably more force, but you should still be able to break.

Would be interesting to hear from somebody how much force is needed with the booster inoperable. Because I have come across cases where it is really ridiculous how hard you need to press. Just a little anecdotal comparison; There have been cases where cars with ABS fitted still skidded all over the place. When investigated the brakes and ABS were found to be in perfect order. The problem was that some drivers (noticeably women) just don’t press hard enough on the brake pedal for the ABS to engage properly.

And that could be the case here as well. I have been in a few situations where I had to drive a car without brake booster. This is usually the situation when you need to tow a broken down car. Power steering and Power brakes don’t work without engine running.

I remember one case where I really had to use all my weight, muscle and power to get the brakes to work. (A VW Touran I believe).

For me that would be a design fault. It’s fine that you need to push harder, but not to the extend that most people would simply not be able to operate. And people, amazingly, are somewhat reluctant to step very hard on the brake, even in emergencies!

It is a very simple test, just disconnect the vacuum line to the booster and try it out. Make sure you do it safely, but you will be surprised on how hard you need to push that pedal on most cars without boost helping you.

Jeroen

[lapis_lazuli]

^ Too hard, probably is the same thing as some unfamiliar users describing as " impossible to brake" @Jeroen! This is where it starts becoming subjective and qualitative, what's hard for me is impossible for others and easier for a burly man! I am certain, there's a standard, that car makers follow, like, e.g. X Newton pedal force will cause deceleration from 50 to 0 in 6 seconds time, for a factory spec brake. Or something on similar lines.

[Sudarshan_N]

The curious case of Hyundai, and now Kia, and their problematic brakes. Thank you for creating this thread.

I’ve read through the entire post and i can totally relate. I’ve been through the exact same ordeal, but with the my 2014 Hyundai Verna. Always had brake issues, always went to the service centre, they always test drove it, but the damn problem never showed up during their test drive. I was soo frustrated .

OMG!! Thank you for this thread.

Story time:

I have been on the lookout for a personal vehicle and had taken short testdrive for KIA SELTOS, have read the initial review and hype/blings on offer. It seemed all great and seemed like a good deal.
During test drive , the same issue happened with the car. My heart sank and mind went blank (Disclaimer - I am a new driver and have driven cars sedatively and with caution). Somehow managed to stop the car, used handbrake before hitting anyone (trust me, i would have been viral on social media and newspaper for killing/injuring someone)

Wow Hyundai. You have introduced different iterations /generations of vehicles and even brought us your partner (KIA), but you are still adamant about maintaining the inherent character of your vehicle (read as stupid brakes).

A friend of mine has bought the Kia Seltos few months back and our main point of discussion before the purchase was the infamous braking issues in Creta. Since we were aware about the parts sharing between Hyundai and Kia, we were very skeptical about the decision to go ahead with the purchase.

But still, we kept our faith in Hyundai/ Kia as a company, believing that they would have addressed the issue in this generation of Creta/ seltos. Alas, you have proved us wrong.

You have been very successful in brushing these issues under the carpet. But how long can you continue to do that. There has been no action right from 2014.

Considering the number of Seltos and Cretas running on our roads and the danger that it may cause to the passengers and road users; this is utter irresponsibility from the manufacturer.

[Nalin1]

It is scary to read when the brake suddenly does not work at just a random time!. That too on a Seltos which is on top of the list of compact SUVs!.

This is probably an underlying issue which needs technicians straight from the manufacturer to investigate, do RCA and finally maybe announce a recall for whatever the fix is. It might be beyond the expertise of the mechanics at the service centre, even more so if they cannot reproduce it.

[CEF_Beasts]

This is a serious issue that Hyundai-Kia have to address, no cover up should be done now! This should be published everywhere on the internet! Brakes failing anywhere and that too randomly without Kia/Hyundai knowing about the issue is criminal on their part! 1st gen Creta has sold 4 lakh units and the Seltos 1 lakh, 5 lakh cars on Indian roads and Kia/Hyundai are happily raking in bookings without addressing this crucial braking Issue. Had this been any other country Hyundai/Kia would have been penalised severely!

[--gKrish--]

This problem was there even from the days of the i10 and it is surprising that they have not figured out a proper solution after all these years.

Come on, how many engineers does it take to properly ascertain the minimum vacuum pressure required for the brake servo to work sufficiently and the minimum engine rpm to be maintained to produce the same?

Also, the anti-stall on Hyundai/Kia vehicles are excessive and on higher gears, this exacerbates the issue. Drivers would get accustomed to keeping the engine at lower revs and the ECU's anti stall would mask the low throttle inputs and people would get caught off guard when the brake gets unexpectedly hard (especially during gradual braking in higher gears or in b2b traffic).

As a rule of thumb, whenever I drive these cars, I follow the following:
Try to maintain a minimum rpm of ~1500 during driving;

While braking to a stop:
if rpm < 1500 : Clutch first then brake( or downshift then brake).
if rpm >1500 : Apply brakes as in a normal car and fully depress the clutch pedal when engine rpm drops to ~ 1300rpm.

[AMG Power]

This apprehension has been at the back of my mind as far as the Kia Seltos was concerned as it has happened to other Hyundai's too - Cretas and Verna's.

Now it has eventually happened with the Seltos too.

The Kia Seltos was quite tempting - especially the 1.4 Turbo manual.

Probable reason:

The pedal becoming hard is an indication of lack of boost. From what has been mentioned I think driving the car slowly (with lower rpm) may have probably led to lower vacuum boost build up (booster failure). This is not a justifiable reason though.

When the pedal becomes hard as a lack of vacuum boost build up, panic sets in and the brain will only register brake failure. Usually when the brake is wooden, it essentially points to a temporary booster failure. To replicate the wooden brake feel experienced by these drivers - roll the car in neutral with the engine off and press the brake - you will get the wooden / reduced braking feel. Although the brakes may not have failed the feel of vastly reduced braking would have led the drivers to think of it as a complete failure.

Nevertheless a booster failure for all practical purposes leads to the same situation as a complete brake failure as most people would not be able to think properly when the pedal becomes very hard and the only thought is the brake has failed leading to panic / lack of proper reactions and the resultant hazardous situations.

[Bibendum90949]

Originally Posted by Jeroen

Brakes do work without brake boost. You will have to stomp a lot harder (and the pedal will feel a lot harder too), but it will brake.

Originally Posted by Jeroen

Irrespective, when a brake booster / enabler fail the brakes should still work normally. They will require considerably more force, but you should still be able to break.

Yes Jeroen, but isn't it easier said than done. Our muscle memory is attuned to the force we normally apply on the pedal. So in the event of an emergency or otherwise, it's highly likely the driver press the panic button since he's caught unawares of the abnormal pedal feel.

Also the owner is not sure of the circumstances(during their diagnosis exercise) that led Kia to decide to change the brake booster.

Originally Posted by srini1785

I cannot but help notice that in both incidents mentioned by @Bibendum90949, the cars were in their highest gear while the speed is only 50Kmph. I am not sure if its AT or MT.

Yes all were during slow speeds. The car where the brake booster has been changed is a manual transmission, 6MT petrol. And the other car where no parts replacements were carried out is an IVT.

Originally Posted by lapis_lazuli

Especially in b2b low speed traffic with AC on. It was due to insufficient vacuum for the brake booster, derived from the intake manifold as there was no separate vacuum pump. They later added a vacuum pump and there was a ECU update for earlier batches, which detected low rpm and on declutching, increased rpm momentarily to create some vacuum enough to brake.

This is exactly what the Kia technician told the owner when he reported back the latest instance of his brake failing, just few days back.

Originally Posted by --gKrish--

Also, the anti-stall on Hyundai/Kia vehicles are excessive and on higher gears, this exacerbates the issue. Drivers would get accustomed to keeping the engine at lower revs and the ECU's anti stall would mask the low throttle inputs and people would get caught off guard when the brake gets unexpectedly hard (especially during gradual braking in higher gears or in b2b traffic).

While braking to a stop:
if rpm < 1500 : Clutch first then brake( or downshift then brake).
if rpm >1500 : Apply brakes as in a normal car and fully depress the clutch pedal when engine rpm drops to ~ 1300rpm.

Valid observation and possibly a good precautionary step one can practise. But just wondering what could possibly a driver do in a car with AT. In this case too, the second car is an IVT. At least in MT, one has the option of forcefully downshifting to the lowest possible gear in an emergency when the brake fails. But AT cars are handicapped in that sense with the revv limiter in play, one can't manually downshift too unless the car reaches a certain rpm, which doesn't help the cause. Only help can be from the hand brake and if it's not used judiciously, one may fishtail or drift off the track.

Originally Posted by guyfrmblr

The brake pedal stars vibrating on bad roads (when there is a change in elevation due to a pothole or when driving over unpaved/broken roads). When this happens, the brakes just don’t work. The pedal doesn’t turn hard but it just vibrates with a sound

This I guess is typical of ABS kicking in and the pulsating feel what you get is as a result of that, and one would indeed feel a loss of braking for a fraction of second. When cars run over broken patches, there would be momentary loss of tyre contact with the road that makes ABS to come into play.

Coming back to the topic, i've the VIN of both these cars. Few common things.

1. Both are manufactured in Feb'20, 6th and 12 th.
2. Both have all four discs.
3. All these issues which had taken place are at slow to very slow speeds.(30-40-50 kmph range).

Point 1 could just be a coincidence, may be not.

[guyfrmblr]

A bit off topic. I face a rather different kind of issue with the brakes of my Seltos. The brake pedal stars vibrating on bad roads (when there is a change in elevation due to a pothole or when driving over unpaved/broken roads). When this happens, the brakes just don’t work. The pedal doesn’t turn hard but it just vibrates with a sound as though some stones are stuck along with the break pads. I complained about it to my SA during 2nd service but he was unaware of this issue. Releasing the brakes and applying again resolves the issue. I have owned 4 cars prior to Seltos but have never experienced this. I thought something was wrong with my car but came across this post in the Sonet thread.

Originally Posted by Saitama

I found the ABS to be a little bit aggressive. The brakes would vibrate sometimes on bad roads for gentle breaking. The SA told me that it was common for KIA cars and Seltos owners also faced the same and complained a lot. He told that on bad roads ABS also kicks in if one of the tyres are about to lose contact due to undulations. He demonstrated the same on the Test car, and told me not to worry.

[vipul_singh]

I have to say, I am getting a 'I told you so feeling'. After pages and pages of complaints on Honda quality, this is what I had to say:

"But I have to say, the only real upgrade option I see is Toyota, based on all the threads I see here, because:

- Maruti: safety, service costs
- Hyundai: service costs, many random issues, some with key control systems
- Kia: looks very promising but too new, plugging unproven tech (iMT, dry clutch DCT). Plus could suffer the same issues as Hyundai"

https://www.team-bhp.com/forum/india...ml#post4907496 (Is it time to move on from brand Honda?)

One can deal with creaks and even water leakages, but it is on-and-off issues with critical control systems which prevent me from aspiring to buy Hyundai / Kia products.

I am also surprised at how long such critical issues have persisted with Hyundai / Kia.

This is not to defend Honda, but just to say that we, as buyers, should be able to judge based on the nature of issues with a given car / brand. Perceived quality and features should not be the be-all-and-end-all when making a purchase decision.

[Godzilla]

This is a scary issue. I will be honest with the group. I never felt Hyundai/Kia cars safe.

• Worst dynamics built-in: I remember when I test drove the i20 and it was the worst of all 25+ cars I tested interms of dynamics. Its behaviour at high speeds with some steering inputs and braking (similar to moose test) was unbelievably horrific. Hyundai prioritised on light steering & soft suspension based on feedback from Indian customers? Sales vs Safety?
  
• Gimmicks prioritised than safety: When I was looking for a car, I prioritised ESP as a critical feature and no diesel variant of Seltos had ESP. An Indian customer pays 20 L and does not get a basic safety feature such as ESP. It is sad that Indians buy such products and make them a grand success falling for gimmicks and ads.
  
• Kills people:I am not sure about the numbers on which brand of cars crash more, but I have seen a Hyundai i20 crash infront of my eyes and the driver was dead on the spot. The car obviously did not have ESP.
  

One way to address this issue is customers supporting brands who prioritise safety such as Ford/Tata. However, that is easier said than done.

This issue could be potentially due to a faulty ABS module. Some interesting links below

"Unresponsive brake pedal
In certain cases, depending on the model of vehicle, when the ABS module fails, the brake pedal may become unresponsive. This is an obvious problem, as an unresponsive brake pedal will not stop a vehicle, or will not be able to do so in an adequately safe manner. In most cases, this will happen slowly, over time. Usually the brake pedal will become increasingly hard to press until it is no longer responsive."

Source: https://www.autoblog.com/2016/01/06/...%20over%20time.


https://www.mycarhelpline.com/index....=720&Itemid=91

Hyundai recalling more than 96,000 vehicles for ABS issue

https://autotalk.com.au/industry-new...0to%20moisture.

https://www.hyundai-forums.com/threa...r-rings.77767/

Hyundai recalls 36,484 cars over faulty braking system

https://auto.economictimes.indiatime...ystem/49176484

[vipul_singh]

Originally Posted by guyfrmblr

A bit off topic. I face a rather different kind of issue with the brakes of my Seltos. The brake pedal stars vibrating on bad roads (when there is a change in elevation due to a pothole or when driving over unpaved/broken roads). When this happens, the brakes just don’t work. The pedal doesn’t turn hard but it just vibrates with a sound as though some stones are stuck along with the break pads.

That seems to be an ABS calibration issue. If you have driven other ABS-equipped cars over the same surface and not faced the problem, it could mean that the Seltos' ABS is kicking in too early and relieving pressure on the discs.

Alternatively it could mean that the ABS system in other cars that you have driven does not remain active at speeds you tested the Seltos on. Some ABS systems are known to not work below certain speeds (like 20 kph).

[Godzilla]

Video link below on how the ABS system works. Kindly note that the root cause could be abs module erratically thinking wheels are locked and reduces brake pressure resulting in no braking. It could happens due to 1. Faulty sensor sending wrong signals (wheels locked signal) to ABS computer 2. Loose Connection issues? 3. Faulty ABS computer 4. Faulty valves.

https://youtu.be/IKi5O3ZlSu4

[rags.singh]

Everything comes at a cost - build quality, safety, looks, bling features, size, comfort etc. That extra metal which some OEMs put in their cars which gives the feeling of a solid built car - comes at a cost. So if you want to keep the price point attractive, you add bling to hide the cost cutting that you have done in the build quality.

Buyers compare the "features" of a car vis a vis the cost and come to a conclusion that so and so car is more bang for the buck while the other car doesn't even have ventilated seats for something that costs 20 big ones! What about the most basic features - build quality and safety?

High time buyers wake up and send a wake up call to the OEMs as well.

[McLaren Rulez]

Originally Posted by vipul_singh

"But I have to say, the only real upgrade option I see is Toyota, based on all the threads I see here, because:

Off topic but Toyota has serious issues with safety systems too.

https://www.team-bhp.com/forum/road-...ml#post4843845 (Big accident in a Toyota Etios, but the airbags didn't deploy!)

This Hyundai/Kia issue is even worse. Perhaps RavenAvi can shed more light on this but it's shocking that they still haven't fixed a safety critical issue like this but are banging on about wireless charging and panoramic sunroofs