[airbus]

Originally Posted by Sen

especially on a top seller like the Seltos and potentially Sonet/Venue/Creta is unacceptable.

Manufacturer recall (for quick retrofit, let them get the issue figured out ASAP first) should happen, and it's a godsend that there have been no fatalities yet.

One of the reasons why I am not too enthusiastic to buy a newly launched vehicle until they are proven on roads for couple of years. Brake failure is a serious issue and root cause must be addressed without waiting for something more serious to happen.

[PYSO]

It would be nice if the Mods communicated with Hyundai and Kia management regarding this serious issue. And if possible share the response of Hyundai / Kia management.

[arindambasu13]

Originally Posted by ChoosetoCruze

You have asked a rhetorical question, to which you already know the answer.

Originally Posted by vsrivatsa

Now I only wonder if this issue is present on the Venue and Sonet as well given that they share the same K2 Platform...

On the contrary, my question was far from rhetorical, and I was genuinely curious about whether there is parts sharing/ OEM sharing between products from different segments in the Kia lineup. I gather from the responses that the answer is a resounding yes.

Certainly hope that Kia resolves this without any further procrastination since the brake failure issue, apart from being life threatening, is totally not commensurate with the market success and hoopla they have hitherto generated with their products. I am myself in the market for a compact SUV, and this really puts a spanner in the works as far as the Kia Sonet is concerned!

[blackwasp]

Thanks to Ravinder for sending this in. Heartfelt gratitude for sharing it with other enthusiasts via this Team-BHP page!

Ravinder shares the email he's written to the Kia Customer Care:

Hello

My car number is HR 02 AT XXXX.

I have faced brake failure issue many times. This issue is also reported by other customers on the Team-BHP portal.

At the speed of 40-50 km/h when I apply brakes, sometimes it’s jammed and feels wooden and I have to use hand brake. This problem has occurred many times, especially when I applied brakes on small potholes and sometimes on normal roads.

As I am from Yamunanagar please resolve this issue in Jagadhari Kia workshop only. I am not able to take the car to Ambala again and again.

Solution for this problem as mentioned in Team-BHP portal is to change the brake booster, as this is done by some Kia service centre.

Please resolve this asap.

[k_ajay]

This is terrible as an issue, on something as basic and life saving mandatory function as brakes.

Is it (unfortunately) safe to assume that this brake issue is also likely inherited by Kia Sonet? Or it will be safe from this issue?

[anb]

Originally Posted by vsrivatsa

So Seltos inherits the known issue from the Creta!

On seeing the Creta Brake Failure thread I had predicted the possibility of this issue being present on the Seltos late last year..

Actually both are completely different issues. Issue in old Creta was brake failure due to faulty rear abs sensors as mentioned by bhpian Naveen Raju. Here the issue is loss of vaccum in brake booster of 1.5 petrol engine models. No Seltos has been identified with a faulty abs sensor.

[Jeroen]

Originally Posted by anb

. Here the issue is loss of vaccum in brake booster of 1.5 petrol engine models.

I don't think that it has been proven that it is the brake booster as such. Or loss of vacuum. Or has it?

It would be interesting to have somebody just test the brakes without vacuum. (Disconnect the vacuum line) and describe the feel of the brakes.

Jeroen

[vsrivatsa]

Originally Posted by anb

Actually both are completely different issues. Issue in old Creta was brake failure due to faulty rear abs sensors as mentioned by bhpian Naveen Raju. Here the issue is loss of vaccum in brake booster of 1.5 petrol engine models. No Seltos has been identified with a faulty abs sensor.

I don't think there is comprehensive evidence to conclude on the root cause of the Seltos issue as yet. Anyhow if we give the benefit of the doubt, in that case also, if we assume that the brake booster is the issue then the worry would be that the 2020 Creta Petrol would also have this issue...so Hyundai-Kia effectively replaced the ABS Sensor issue of the past with a new brake booster issue that creates identical end result to the customer

[a4anurag]

Originally Posted by Jeroen

It would be interesting to have sombody just test the brakes without vacuum. (Disconnect the vacuum line) and describe the feel of the brakes.

I have tried disconnecting the vacuum line and have driven the car in a closed environment - brakes were working as such but the pedal was completely wooden. Hardly any movement was possible. Was literally 'standing on the pedal' to get the car to stop from ~30 kmph. It is the similar 'feeling of the pedal' that I have felt whenever in the past the pedal went hard during braking.

Not sure but my feeling is this 'hard pedal' feel is mainly related to the brake booster whereas the juddering on the pedal felt while braking on uneven surfaces is due to 'over-sensitive' ABS (sorry if there is no such word but that's how I can describe with my limited technical knowledge).

[Jeroen]

Originally Posted by a4anurag

I have tried disconnecting the vacuum line and have driven the car in a closed environment - brakes were working as such but the pedal was completely wooden. Hardly any movement was possible. Was literally 'standing on the pedal' to get the car to stop from ~30 kmph. It is the similar 'feeling of the pedal' that I have felt whenever in the past the pedal went hard during braking.
.

Thanks, that sort of confirms what I was suspecting all along. On modern cars, when the brake booster fails, you need to press very very hard on the pedal. And as you experience you get a very different feel in your brake pedal too.

I think there are two different issues here:

1) The amount of force needed to brake if the brake booster is out of order
2) Why the brake booster exhibits this seemingly random behaviour

On the first aspect; It is all very well for car manufacturers to state that in case of brake booster failure the brakes still work. But if in practice it takes just way too much force, I think it is just incorrectly designed.

On the second aspect; obviously the root cause must be found. The most obvious culprit is likely to be the vacuum somehow. But then again, why would the vacuum be a problem. Again, if the engine (petrol) does not produce enough vacuum with the engine idling, or any RPM for that matter, I think that is an incorrect design.

Pumping the brakes, again not a hugely valid excuse in my opinion. Mind you, if you check your manual you will probably find something on not pumping the brakes! Especially on cars with ABS you should not pump the brakes as that interferes with the normal working of the ABS.

What I can imagine is that if for some strange reason the vacuum is insufficient and you hit the brake, the brake feels very different, you might hit the brake a couple of times. At which point any remaining vacuum is completely gone. I think it is pretty normal response to a situation where your brakes don’t feel ’normal’, people tend to pump then. So again, a design issue.

I can think of some scenario where this could happen due to some very rare failures of other components perhaps? It will be interesting to see if the manufacturer/dealer comes with any sort of response.

Jeroen

[sudeepg]

Originally Posted by Jeroen

... that sort of confirms what I was suspecting all along. On modern cars, when the brake booster fails, you need to press very very hard on the pedal.

In which case Hyundai/KIA should be able to reproduce this problem with retuning the ECU AND/OR disabling the anti-stall function and test if the brakes indeed are very hard to apply?

[Jeroen]

Originally Posted by sudeepg

In which case Hyundai/KIA should be able to reproduce this problem with retuning the ECU AND/OR disabling the anti-stall function and test if the brakes indeed are very hard to apply?

it is much simpler than that; just disconnect the vacuum line to the booster. Plug of the side to the engine, leave the side to the booster open to the air.

Nothing else is needed. Takes 10 seconds, if that!

Jeroen

[sudeepg]

Originally Posted by Jeroen

it is much simpler than that; just disconnect the vacuum line to the booster. Plug of the side to the engine, leave the side to the booster open to the air.

Nothing else is needed. Takes 10 seconds, if that!

Jeroen

Hmmm... I see your point about not having any vaccum support causing the pedal getting hard enough to provide sufficient braking force. My question was more around another gentleman noting that the lack of enough RPMs to support the vaccum within the booster.

[a4anurag]

Originally Posted by Jeroen

Mind you, if you check your manual you will probably find something on not pumping the brakes! Especially on cars with ABS you should not pump the brakes as that interferes with the normal working of the ABS.

Yes, the owner's manual does mention to avoid pumping the brake pedal continuously.

Attaching screenshots from the Owner's Manual

[momsonlydriver]

People here are recommending as to how to apply the break and the method of application of the clutch pedal.

My question is that this problem is only being faced in manual transmission cars or even the automatic transmissions are facing the same issue?

I personally never faced any issues regarding breaking. Whenever I want to stop the car, I press the break pedal and it stops like the way a car should do.