[humyum]

Originally Posted by bala80

Firstly thank you for the informative post.

Are you implying it is impossible to get the wheels locked in the L/V DI variants since it doesnt feature brake assist? I never could get the wheels locked in my swift during emergency braking and that was my major complaint against it. Wouldn't you attribute the locking of wheels on non-ABS model to be maximum braking force/bite that can be acheived? (Its a different story that the maximum braking is not equal to effective braking as it has to be on the threshold point just before the wheels get locked up)


As humyum mentioned above, Im too one of those who got the booster assembly of my earlier generation swift changed and my understanding too was that they had replaced the old 10 inch booster with a 11 inch booster. Pardon my ignorance but for changing the servo ratio, does the entire booster assembly has to be replaced?

Ditto, I can live with wheels locking up than wheel not stopping the car in time at all. The braking efficiency of a car sure can be found out by 'if the wheels lock or not. Yes the brake booster in the older swift was 10 inch one and was replaced by the 11 inch one and it's mentioned in the bill too.

[Viju]

Originally Posted by humyum

Yes the brake booster in the older swift was 10 inch one and was replaced by the 11 inch one and it's mentioned in the bill too.

Originally Posted by bala80

Are you implying it is impossible to get the wheels locked in the L/V DI variants since it doesnt feature brake assist? I never could get the wheels locked in my swift during emergency braking and that was my major complaint against it. Wouldn't you attribute the locking of wheels on non-ABS model to be maximum braking force/bite that can be acheived? (Its a different story that the maximum braking is not equal to effective braking as it has to be on the threshold point just before the wheels get locked up)


As humyum mentioned above, Im too one of those who got the booster assembly of my earlier generation swift changed and my understanding too was that they had replaced the old 10 inch booster with a 11 inch booster. Pardon my ignorance but for changing the servo ratio, does the entire booster assembly has to be replaced?

Dear humyum and bala80

I happen to be working for Maruti Suzuki's R&D Division in Gurgaon. Although I do not represent the company or its views in any way, I felt the need to make a few clarifications.

I would like to answer the questions one by one.
(1) I am not implying that one cannot get the wheels locked if the vehicle does not have Brake Assist feature. If the driver applies sufficient force on the brake pedal, the wheels will lock. What Brake Assist does is, to detect an emergency braking situation (using the pedal travel rate), and automatically increase the brake boost so that maximum brake pressure is applied at the wheels, even when the driver does not apply sufficient force on the pedal, due to panic. Since a vehicle with Brake Assist will always have ABS, it will ensure that the wheels don't get locked, and at the same time, maximum brake force is applied for the best possible stopping distance.

(2) The Swift, old or new, always came with a 9 inch brake booster. Like I mentioned above, all that MSIL did was to change the servo ratio of the booster. I can say this with confidence because I have been closely involved with the development of these models.

And to answer your query, bala80, a brake booster consists of two shells crimped together (which will have to be cut open) with all its mechanical components inside. To change the servo ratio, you need to change a component inside the booster (known as the valve body) which cannot be done without replacing the entire booster assembly. Once cut open, the shells cannot be crimped back together.

Also, if a 9 inch booster seems like a compromise for the class, please know that other vehicles in the category like the Toyota Etios use the same size of booster. The only vehicle to use a 10 inch size booster in the class is the Indica Vista, mainly due to the fact that it is a much heavier vehicle. In fact, larger vehicles like the SX4 or Honda City use 10 inch boosters. 11 inch boosters are used only in SUVs.

It is not only the size of the booster which determines the brake performance of a vehicle. It is a combination of the booster, wheel brakes and proportionating valve specification.

Sorry for the long post.

[bala80]

@Viju - Again a very informative post, thank you very much for taking your time and clarifying things and I agree few of my opinions on this subject were misplaced till now. The information you provided adds great value to this discussion and is much appreciated.

Originally Posted by Viju

I happen to be working for Maruti Suzuki's R&D Division in Gurgaon. Although I do not represent the company or its views in any way, I felt the need to make a few clarifications.

[Sutripta]

Originally Posted by Viju

Dear humyum and bala80

I happen to be working for Maruti Suzuki's R&D Division in Gurgaon. Although I do not represent the company or its views in any way, I felt the need to make a few clarifications.

Originally Posted by Viju

(1) What is Brake Assist?
In emergency braking situations, drivers tend to press the brake pedal quickly, but due to panic, not keep the brake pedal pressed fully. Brake Assist is a feature which can sense this rapid travel of the brake pedal and increase the brake boost automatically. Mechanical brake assist (present in cars like the Swift), uses a mechanical system inside the brake booster to increase the boost automatically when panic braking is judged, thus increasing the braking force at the wheels.

Hi,
Could you please expand on the mechanical part?

Regards
Sutripta

[ghostrider]

Thank you Viju for posting on this this thread in a factual manner.

When I TD'd the new Swift VDi I didn't get an opportunity to really test the brakes so I won't comment on whether the brakes are inadequate or not.

What does surprise me though is that I have a Gen-2 VDi, and it has some of the best brakes I've ever had. The braking is precise and reliable, which is something sorely lacking in my Ikon 1.6, a car renowned for it's engine and handling but much maligned for it's inadequate brakes.
I also have an NHC, and its brakes arent as good as the VDi. The problem I face with the NHC is indifferent braking... for about 40% of the pedal's travel there's negligible braking and then they bite with a bang, which leads to lockups if you're not completely used to it.

My Gen-2 VDi (without ABS) on the other hand had extremely predictable braking behavior and even under extreme braking conditions I've never felt like the stopping power was inadequate. Yes, the wheel's do lockup (rarely) but I've never had the "Oh-my-God-I'm-going-to-hit-the-guy-in-front" sensation that I frequently get from the Ikon.

Anyone else here driven both the Gen-2 and Gen-3 VDis? Comparative thoughts?

[im_srini]

Originally Posted by Viju

...Mechanical brake assist (present in cars like the Swift), uses a mechanical system inside the brake booster to increase the boost automatically when panic braking is judged, thus increasing the braking force at the wheels.

Hi Viju, by "mechanical brake assist", are you referring to a dual ratio/rate brake servo ?
Do the Altos (F8/F10 & K10) come with such a servo ?

Originally Posted by Viju

Brake Assist increases the brake boost, taking the braking force up to the wheel locking condition.

Is this "brake assist" an electronic system (in contrast to the mechanical system alluded to above) ?

[suman]

Originally Posted by ghostrider

Anyone else here driven both the Gen-2 and Gen-3 VDis? Comparative thoughts?

The thread starter himself has, see this post -
http://www.team-bhp.com/forum/techni...ml#post2541630

[humyum]

Originally Posted by ghostrider

Thank you Viju for posting on this this thread in a factual manner.

When I TD'd the new Swift VDi I didn't get an opportunity to really test the brakes so I won't comment on whether the brakes are inadequate or not.

What does surprise me though is that I have a Gen-2 VDi, and it has some of the best brakes I've ever had. The braking is precise and reliable, which is something sorely lacking in my Ikon 1.6, a car renowned for it's engine and handling but much maligned for it's inadequate brakes.
I also have an NHC, and its brakes arent as good as the VDi. The problem I face with the NHC is indifferent braking... for about 40% of the pedal's travel there's negligible braking and then they bite with a bang, which leads to lockups if you're not completely used to it.

My Gen-2 VDi (without ABS) on the other hand had extremely predictable braking behavior and even under extreme braking conditions I've never felt like the stopping power was inadequate. Yes, the wheel's do lockup (rarely) but I've never had the "Oh-my-God-I'm-going-to-hit-the-guy-in-front" sensation that I frequently get from the Ikon.

Anyone else here driven both the Gen-2 and Gen-3 VDis? Comparative thoughts?

By the generation 2 swift, Do you mean the swift which came with the upgraded brake booster or did you get your's upgraded to the 2009 end and later model's brake booster.

I agree with you, mine is with an upgraded brake booster 2008 December Swifts and the braking is sharp and never have I ever felt after the upgrade that the car will go into something or someone.

I ll be able to compare the brake's of my swift Diesel and the new swift diesel as I went to test drive it thrice. The test drive was taken after reaching the destination in my Swift diesel. So its a direct comparo.

Initially there is no bite in the brakes of the ZDI. It feels like the brake discs and the pads are just sliding away but when you put the foot down on the brakes at high speeds, suddenly after a point it starts decelerating at a rapid pace, which I think is the brake assist coming into the picture. But still even with the brake assist coming into the pictures, the brakes don't have 'THAT' bite that my Swift diesel has even though my brake pads are like 20 thousand kilometre's old.

In the end I would say maruti instead of going for the brake assist and all that natak, they should have kept the brakes how they were while the brake booster was upgraded

[CrAzY dRiVeR]

Is this issue felt in LXi/ VXi variants as well? Or is it felt mainly in the diesel because of the torque pull?

Originally Posted by Viju

I happen to be working for Maruti Suzuki's R&D Division in Gurgaon. Although I do not represent the company or its views in any way, I felt the need to make a few clarifications.

Viju,

Thanks for making it clear that you are working with MSIL. Its great to have you onboard. I understand that you do not represent the company, but it would be great if you can help to get this issue to the attention of the 'right' people.

Although I test drove and booked the ZDi (brakes felt much better than the current non-ABS WagonR i drive), its really disconcerting to know many people are complaining of poor brakes in a car we are willing to wait 6+ months for!

[goandude]

Originally Posted by humyum

Yes the brake booster in the older swift was 10 inch one and was replaced by the 11 inch one and it's mentioned in the bill too.

Originally Posted by Viju

(2) The Swift, old or new, always came with a 9 inch brake booster.

Sorry for the long post.

was confused as to how there is such differences in opinion on the size of the booster, so I measured it and to put to rest the size is 9" as you can see from the pic below
This is from my Jul 2009 Dzire which had the booster changed in Dec 2010 after complaining to MSIL about weak brakes

[deetjohn]

Originally Posted by goandude

was confused as to how there is such differences in opinion on the size of the booster, so I measured it and to put to rest the size is 9" as you can see from the pic below

This is from my Jul 2009 Dzire which had the booster changed in Dec 2010 after complaining to MSIL about weak brakes

Appreciate the effort goandude.

That booster is close to 23 cm = 9"

Edit: I had heard that Maruti fixed the issue by replacing the old booster with a bigger one. Now we know that was not the case as rightly mentioned by 'Viju'.

[autocrat]

Originally Posted by ghodlur

OMG, thats a huge compromise on Safety by Maruti Suzuki. One thing that puzzles me was this not noticed during the test drive? Has this been shown to the workshop, whats their view on the same?

If this is an one off case then your car might be one of the sabotaged lot. I think Maruti's claim of 1L+ booking of the new swift will take a major hit if this issue is for real in all the new swifts.

Usually test drive is offered only in the top variants of cars. Buyers don't realize the differences until they take delivery. Its always a good idea to test drive the variant you wish to buy. If the dealer does not offer that variant for test drive, check if you have any friends who have bought that variant and get a drive.

Most of the 60~0 / 80~0 tests (and other braking tests) that the automobile goes through even during ARAI tests are all in standard conditions, which are quite different from the regular driving conditions.

[specialist1968]

Originally Posted by Viju

Dear humyum and bala80

I happen to be working for Maruti Suzuki's R&D Division in Gurgaon. Although I do not represent the company or its views in any way, I felt the need to make a few clarifications.

I would like to answer the questions one by one.
(1) I am not implying that one cannot get the wheels locked if the vehicle does not have Brake Assist feature. If the driver applies sufficient force on the brake pedal, the wheels will lock. What Brake Assist does is, to detect an emergency braking situation (using the pedal travel rate), and automatically increase the brake boost so that maximum brake pressure is applied at the wheels, even when the driver does not apply sufficient force on the pedal, due to panic. Since a vehicle with Brake Assist will always have ABS, it will ensure that the wheels don't get locked, and at the same time, maximum brake force is applied for the best possible stopping distance.
.....................

Thank you Viju. Presence of people like you make the forum more meaningful. Thanks for writingin. We look forward to you for taking our views further forward.

I drive a new ZDi. As Viju has pointed out, I feel a sudden braking effect when pressing the pedal quick, with the braking force coming much earlier than usual. In the other situations, I need a longer brake travel and feel a bit uneasy with the braking manners as things feel spongy out there. Here again I need to get adjusted to the system and change my driving style. Two different behaviours in two different situations make me confused. This may not be the right policy to adopted in the braking department for a car. Surely the vehicle's brake system in the non-panic situation requires re-calibration.

Also, the vehicle following you do not have brake assist most times.

[Viju]

Originally Posted by Sutripta

Hi,
Could you please expand on the mechanical part?

Regards
Sutripta

Dear Sutripta

Mechanical brake assist works using a spring, ball and locking mechanism in the booster, which is a bit difficult to explain without cut-section diagrams. Give me some time. I will put together a simple explanation of the system or dig out some material I might have. Thank you for asking.

Originally Posted by im_srini

Hi Viju, by "mechanical brake assist", are you referring to a dual ratio/rate brake servo ?
Do the Altos (F8/F10 & K10) come with such a servo ?
Is this "brake assist" an electronic system (in contrast to the mechanical system alluded to above) ?

Dear im_srini

(1) Dual ratio / rate brake servo boosters give the boost assist in two stages, and is not related to mechanical brake assist. This is usually used when a bigger size (say 10 inch) booster is required to give sufficient braking performance to the vehicle, but the layout in the engine room is so constrained that only a smaller booster (say 8 inch) can be packaged in it. In this case, an 8 inch booster with dual ratio servo can be used to give pretty much the same assist as a 10 inch booster.

And no, the Alto does not come with such a system.

(2) The "electronic" / "hydraulic brake assist" is available only in vehicles equipped with ESP (Electronic Stability Program). In case of Maruti, the Kizashi comes equipped with Electronic / Hydraulic Brake Assist.

Originally Posted by humyum

In the end I would say maruti instead of going for the brake assist and all that natak, they should have kept the brakes how they were while the brake booster was upgraded

Dear humyum

Brake Assist is not new to the new Swift. It was present in the ABS variants of the old Swift and is also present in almost all ABS-equipped variants of MSIL as well as other OEMs. And at least specification-wise, the brakes indeed are how they were while the brake booster was upgraded.

Originally Posted by CrAzY dRiVeR

Is this issue felt in LXi/ VXi variants as well? Or is it felt mainly in the diesel because of the torque pull?

Viju,

Thanks for making it clear that you are working with MSIL. Its great to have you onboard. I understand that you do not represent the company, but it would be great if you can help to get this issue to the attention of the 'right' people.

Dear CrAzY dRiVeR

I do understand that the concern is genuine. You can be rest-assured that team-bhp is a forum which is so widely read that it always gets the message to the 'right' people.

And yes, the feeling may be more pronounced in LDi / VDi due to the difference in characteristics of the K12 and D13 engines.

Originally Posted by goandude

This is from my Jul 2009 Dzire which had the booster changed in Dec 2010 after complaining to MSIL about weak brakes

Dear goandude

Really appreciate your effort!

Originally Posted by specialist1968

Thank you Viju. Presence of people like you make the forum more meaningful. Thanks for writingin. We look forward to you for taking our views further forward.

Dear specialist1968

As a long-time member of team-bhp, although mostly passive, I will do what I can to take the community's views forward. Cheers.

[moralfibre]

Gentlemen,
Sorry, I had been away due to some personal reasons. I have an update:

The car completed about 5700 kms on Thursday and it was time to book my second service appointment and so I did for Saturday. Took the car into the service station at 7:30 am and told the service advisor about the brake issue. He said that he doesn't suspect any issues and will clean the brake pads. I added that he should bleed the brakes for my satisfaction.

I usually standby in the customer lounge and see my car being worked upon. The mechanic assigned to me diligently scrubbed the brake pads using sand paper. Bled the brakes (it takes 3 people to do so). And put everything back in place. The SA and I went on a test drive and I felt no difference other than the brake pedal travel that had reduced. This is an obvious development after brake bleeding. The brakes are as soft and spongy as before and there is no visible brake bite until you really stand on the brakes. It takes while for the car to slow down as well. The service advisor confirmed that the brakes on the ABS equipped variant are much better and the Swift does lack braking performance.

Another SA quietly told me that brakes on the Swift are its weakest point. So, we are back on square one. I'd like to know a few email addresses in Maruti Suzuki to whom I can refer this problem.

On similar lines, my twin sister bought a Ford Figo ZXi last week (non-ABS) and the brakes on that are wonderful. Same driver, same driving style, different cars.