[sportz_kruzer]

Hi everyone! I own a Alto LX 2007 model which has done 40k kms till date. Of late a strange problem has developed. The braking efficiency seems to change every now and then. At times the braking is fine and at times I have to press more/harder to obtain the same effect. It is as if the engine vaccum assistance if faltering at times. Put in other words you would get the similar feel when you brake with the engines off (no assistance). Although this is only to a certain extent. I think this happens more after a low rpm bumper to bumper kind of driving.

Gurus can you please help me out? I almost rear ended another car one day as the brake didnt respond the way it usually did and required a much harder push!

[ajman28]

Does this particular model come with power assist for brakes?

[sreedotk]

Could be brake fade. Usually when you are running bumper to bumper traffic you are on and off the break which could heat it up and Steel breaks tend to lose friction when heated beyond their operating temperature leading to brake fade.

http://en.wikipedia.org/wiki/Brake_fade

[xenxer]

I also face this issue with my ZEN. but only at times. In mine it isn't depended on low or high speeds. I had this from the very beginning (the day i purchased the car). Several visits made to M.A.S.S but they say they can't find any issues. This is because they test by hard braking and its working fine. But we give brake pressure according to situations and at certain times it seems not effective. M.A.S.S have tested the brakes and power assist and said no issues. Brake fluid is also good and to level.

Now i got used to it but if any one have any suggestions it will be helpful.

[911turbo]

No Offence, but i guess brakes heat up in case of continuous running and braking(long runs)... In bumper to bumper traffic, brakes will not get that hot that it fades and they fail to operate.

Check your brake oil level and get your brakes checked for any uneven wear and tear and also check any leakage in the braking system. Check for any vibrations in the brake calipers and the master cylinder.

[somspaple]

even 've experienced problem with brakes in our wagonR. but only couple of times and this is little different. it was as if the brakes pads were travelling free all the way down without any effect. after you pump it couple times- it comes back to life. strange but never experienced this problem offlate though.

[narendra.vw]

Please check the vacuum line starting from brake booster untill vacuum pump. See if there is any brittle or spongy rubber hose connected to vacuum line. To check the vacuum pump, remove the link leading to booster. Start the engine, place your thump on the opening side of the link. If you have sucking feel on your thumb, then the pump is OK. Change the hose pipe of vacuum line, it will work fine.

[vigsom]

Originally Posted by sportz_kruzer

Hi everyone! I own a Alto LX 2007 model which has done 40k kms till date. Of late a strange problem has developed. The braking efficiency seems to change every now and then. At times the braking is fine and at times I have to press more/harder to obtain the same effect. It is as if the engine vaccum assistance if faltering at times. Put in other words you would get the similar feel when you brake with the engines off (no assistance). Although this is only to a certain extent. I think this happens more after a low rpm bumper to bumper kind of driving.

Gurus can you please help me out? I almost rear ended another car one day as the brake didnt respond the way it usually did and required a much harder push!

Since your car is only 3 years old,I can't suspect anything but brake pads/disc.Have them checked.Your brake pads might need to be replaced.

Though these are ventilated discs,there is a drop in braking efficiency when they heat up.

Another advice-slow down

[JustCause]

I also had this problem of unpredictable braking after I had to stop from 80-0 (cow on the base of flyover ). Initially, I thought it was normal, but my SA diagnosed & rectified it at regular service at no excess charge& casually mentioned this 'adjustment' it as I was about to leave. I thanked him profusely.Go to any MASS & get it fixed. Brake pads make an annoying squeal & groan while braking as they near death, tell me, do you hear that sound?

[speedsatya]

I had the same problem at around 40 k kms in my zen .And this was also in the fourth year ,about 2-3 months from the expiry of the 4th year warranty .The brakes had similar behaviour whenever the AC was on.Initially the MASS refused to acknowldege this and used to change the pads and the brake oil everytime I used to point this out.
But this time ,luckily this problem happened when the service advisor was driving.

This was traced to a faulty brake vacuum booster.

If you have opted for Extended Warranty ,then your car is still covered for a free replacement

[sportz_kruzer]

Originally Posted by xenxer

I also face this issue with my ZEN. but only at times. In mine it isn't depended on low or high speeds. I had this from the very beginning (the day i purchased the car). Several visits made to M.A.S.S but they say they can't find any issues. This is because they test by hard braking and its working fine. But we give brake pressure according to situations and at certain times it seems not effective. M.A.S.S have tested the brakes and power assist and said no issues. Brake fluid is also good and to level.

Now i got used to it but if any one have any suggestions it will be helpful.

Bang on! thats exactly what iam facing. I used to face this when the car was new but i assumed it was my imagination as it this was my first car...and the a.s.s , like you said told me everything is fine. But now this issue is really getting on my nerves.

Originally Posted by 911turbo

No Offence, but i guess brakes heat up in case of continuous running and braking(long runs)... In bumper to bumper traffic, brakes will not get that hot that it fades and they fail to operate.

Check your brake oil level and get your brakes checked for any uneven wear and tear and also check any leakage in the braking system. Check for any vibrations in the brake calipers and the master cylinder.

Brake oil is fine. Yes brake pads and calipers can be suspect as there are certain under body noises from from right side when the car goes over mildly rough surfaces. will check that!

Originally Posted by somspaple

even 've experienced problem with brakes in our wagonR. but only couple of times and this is little different. it was as if the brakes pads were travelling free all the way down without any effect. after you pump it couple times- it comes back to life. strange but never experienced this problem offlate though.

oops that a serious problem if what you have written above is true. Please get it rectified asap. what you have mentioned typically means "Brake failure". The same thing happened to a friend of mine who has a wagonr 2001 model. He was at 80kmph when an auto came in the middle. He braked hard, although he had good distance left, he hit the auto hard enough for it to be tossed up 3 times in the air before landing straight! Even the had to say the same thing - I pressed it all the way down - but the damn thing didnt dtop!

Its not that my car doesnt brake at all. Its like lets say i have to give 1kg of pressure to drop the speed from 80 to 60 and next time for the same speeds i may have to give 2 kg of pressure. You know one makes up a subconscious mental map of pressures to be exerted on different pedals of a particular car, but this some seems to change the specifications from time to time. Wonder whats goin on!?

Originally Posted by JustCause

I also had this problem of unpredictable braking after I had to stop from 80-0 (cow on the base of flyover ). Initially, I thought it was normal, but my SA diagnosed & rectified it at regular service at no excess charge& casually mentioned this 'adjustment' it as I was about to leave. I thanked him profusely.Go to any MASS & get it fixed. Brake pads make an annoying squeal & groan while braking as they near death, tell me, do you hear that sound?

Yes! it does groan at me but only when let say car is about to come to a stop - say around 3-5 kmph and also at times when it just stats to move. Is this what you are referring to?

Originally Posted by xenxer

I also face this issue with my ZEN. but only at times. In mine it isn't depended on low or high speeds. I had this from the very beginning (the day i purchased the car). Several visits made to M.A.S.S but they say they can't find any issues. This is because they test by hard braking and its working fine. But we give brake pressure according to situations and at certain times it seems not effective. M.A.S.S have tested the brakes and power assist and said no issues. Brake fluid is also good and to level.

Now i got used to it but if any one have any suggestions it will be helpful.

from what i know there is a vaccum hose pipe from brake hub (or whatever they call it) to the throttle body on the engine. By brake hub I mean the big round thing on the wall - behind the engine in the hood - just below where you fill brake oil. It has metal pipes coming out of it.

That reminds me I know a zen which has totally lost it vaccum assistance. Braking is just like the 800 - you got to hit it hard! but atleast it behaves consistently! Wonder what will I do during rains!

Originally Posted by ajman28

Does this particular model come with power assist for brakes?

Yes it does! It had what you'd call touch - braking when it was new!

Originally Posted by narendra.vw

Please check the vacuum line starting from brake booster untill vacuum pump. See if there is any brittle or spongy rubber hose connected to vacuum line. To check the vacuum pump, remove the link leading to booster. Start the engine, place your thump on the opening side of the link. If you have sucking feel on your thumb, then the pump is OK. Change the hose pipe of vacuum line, it will work fine.

I got it! you mean that black hose going from the black round thing which sits below the brake fluid - to the top of the engine. Will check that asap!

[JustCause]

Originally Posted by sportz_kruzer

Yes! it does groan at me but only when let say car is about to come to a stop - say around 3-5 kmph and also at times when it just stats to move. Is this what you are referring to?

Your pads are to be checked considering your reply. I seriously think something is off here. Either the caliper is failing or there is some blockage/ fouling in the brake components. I don't think it is brake fade. Update when you try the things mentioned by narendra.vw

[911turbo]

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[911turbo]

Originally Posted by sportz_kruzer

Brake oil is fine. Yes brake pads and calipers can be suspect as there are certain under body noises from from right side when the car goes over mildly rough surfaces. will check that!

Or you can just, touch the brake caliper and look for some uneven play...if there is any.. get it checked..

[sportz_kruzer]

Bang on 911! Khn.. Khn.. is what is said! A shaky caliper and a loose pin were the culprit! Also the inner brake pad showed abnormal level of wear (almost 95%) as compared to the rest of the pads (50% wear). Got then changed and the problem is now gone! Thanks everyone for your kind support!