Safe Speed Forums

We currently have three pool cars available for use at work and one of them is a Peugeot 207. I have earlier this week submitted a complaint which I think is a serious fault. This is what I have written to the main dealer…

"When you depress the brake peddle in an emergency fashion, as if a child has just run out into the road, there is no braking for the first fraction of a second and a loud ‘air-type’ noise emanates from the nearside of the car during this short period. You can repeatedly ‘stab’ the brake peddle in fact and observe the same problem. (No braking whatsoever).

The air noise can be heard from both the inside and outside of the car when stationary. If you keep the brake depressed it does work normally but only after a significant initial delay. This is not normal and potentially dangerous in such an emergency stop situation of course and a big concern as to whether it is likely to get worse or completely malfunction!"

The feedback I have had so far from Peugeot is that it is normal. I don't think it is. I know the sound of air is normal, although it is very loud on this car. Their 'top man' has kept it to give it a full road test over the next few days after speaking with me over the phone. His tone, however, is one of nothing wrong.

Now I know on any other power-assisted vehicle I have driven, if I were in an emergency brake situation and “stabbed” the brake peddle my head would nearly come off the very moment my foot touched the rubber on the peddle, not after the vehicle has considered what I’m doing for a fraction of a second.

I would estimate the delay I talk of to be only about half a second. Not much, I know, but at 70 mph this would equate to quite some distance. (Haven’t done the math yet). Indeed, even at 30mph those few feet could make all the difference IMO.

Am I right about this? Are there any experts in this field here because if Peugeot are going to tell me this is normal, which is what I'm getting so far, I have to say I think it is a serious design fault!

Other cars are not like it, or certainly not nearly as bad. I know because I’ve since tried it in a Mazda 323, Octavia, Astra and my old Polo. It brakes on the 'B' of Brake.

Is it the difference between power assisted only and ABS? If so, I'll just have the power assisted thanks.

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The views expressed in this post are personal opinions and do not necessarily represent the views of Safe Speed.
You will be branded a threat to society by going over a speed limit where it is safe to do so, and suffer the consequences of your actions in a way criminals do not, more so than someone who is a real threat to our society.

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The world runs on oil, period. No other substance can compete when it comes to energy density, flexibility, ease of handling, ease of transportation. If oil didn’t exist we would have to invent it.”

56 years after it was decided it was needed, the Bedford Bypass is nearing completion. The last single carriageway length of it.We have the most photogenic mayor though, always being photographed doing nothing

An action time of 500ms of the brakes sounds very wrong. I've never driven a car that does that.

Does the pedal quickly go to the final position when you first press it and no further when the brakes bite, or does the pedal instead continue moving as the brake bites?

Using simplistic assumptions: half a second at 70mph equates to nearly 16 meters (an additional 17% ontop of the standard stopping distance); at 30mph = nearly 7 meters (30% more)

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

The peddle feels like it hits a block of wood wedged underneath before easing off a little, that’s the best way I can describe it I think Steve. Oh and thanks for the maths It's hard to time it but I won't be far off saying it's ~500ms.


Thanks for the link Jom, I still don’t get it though


Other cars don’t do it and, at the risk of arrogantly sounding like I know more than car manufacturers, I think I know what is potentially an emergency situation more so than the car. If I hit the brakes I want to feel like I’m braking with immediate effect, don’t we all, and surely that is also minimizing the stopping distance?

The reason I discovered this in the first place was when a small brown-looking bag blew in front of me from between parked cars. I thought it was an animal so, with my usual cat-like reactions, hit the brakes before realising what it was and so took my foot back off. I was horrified when my whole action resulted in absolutely nothing! How can that possibly be good or safer than conventional ABS?

As I understand these things, ABS should poll the wheels to check for any lock-up but yet still kicks-in within thousandths of a second – good! But if BA vehicles can’t do the same and adds a delay I have to say I honestly wouldn’t want it. I took my friend at work out in it to demonstrate what I was saying, an advanced driver himself, and he agreed with me. (His Ford Focus doesn’t do it either).

To put it another way, if it was an animal and I did have to keep my foot on the brake I would have just lost ‘however many’ yards of stopping distance. (Well, about 7 metres I'm told ) Now if that’s what BA does I am really truly shocked and find it hard to believe it’s an improvement over conventional ABS.

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The views expressed in this post are personal opinions and do not necessarily represent the views of Safe Speed.
You will be branded a threat to society by going over a speed limit where it is safe to do so, and suffer the consequences of your actions in a way criminals do not, more so than someone who is a real threat to our society.

I understand that many cars of all shapes and sizes often have a "dead" feel at the top of their travel, with meaningful retardation only beginning after the first 1/4 or 1/2 inch of pressure. I remember the Lamborghini Gallardo Superleggera being slated in EVO's CoTY a couple of years ago for that reason (and also difficult modulation over braking strength).

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Simon

I have a 207 and tried this out today, but didn't experience any noticeable delay before braking.

I'd never noticed the air noise before, either - obviously I don't do enough emergency stops

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"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

Well maybe then, I hope, this is a real fault. But somehow I feel it isn't and likely to get a "No problem" from the big P. (It would be in their best interest to say as such or fix and and say there was nothing wrong ) But if it comes back like it went, I promise I'll feedback on this and even try and post something more graphic with my cam like I did with Kev, (Advance driver man).

There is no doubt in my mind this is bad. I'm talking about a heart-stopping foot-stomping moment! You wouldn't even notice it during normal driving which is why no-one has, until my event.

In a race to stop, (if that makes sense), I could nail my 10 year old Polo to the floor with more alacrity in the first 7 metres at 30 mph than this modern-day 207 while it thinks about stopping and I gain, or is it lose, ~7 meters. I would seriously bet silly money on it!!!

I'm on a mission, but I can't do any more for now until we have it back. Maybe early next week...

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The views expressed in this post are personal opinions and do not necessarily represent the views of Safe Speed.
You will be branded a threat to society by going over a speed limit where it is safe to do so, and suffer the consequences of your actions in a way criminals do not, more so than someone who is a real threat to our society.

Sounds like a fault to me! Can't think of a single (healthy!) vehicle I've ever driven that does that! Even on cars with fully-powered braking systems (like the old big Citroens) as opposed to servo-assisted ones, the response times are much shorter. Have you braked hard enough to get the ABS to cut in? Try it when you get the car back and see what it does. Let us know what the man says!

I think its your emergency brake assist.
The system tries to decide from your pedal movement and braking whether you want emergency braking and if so it applies the brakes to the maximum and balances the braking as well as abs. I doubt that it takes half a second though.

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The world runs on oil, period. No other substance can compete when it comes to energy density, flexibility, ease of handling, ease of transportation. If oil didn’t exist we would have to invent it.”

56 years after it was decided it was needed, the Bedford Bypass is nearing completion. The last single carriageway length of it.We have the most photogenic mayor though, always being photographed doing nothing

I'm sure the ABS cuts in after the delay although I didn't try it. I'd need to find an bare open stretch of road of course but I'll give it a go when it comes back. The ABS certainly doesn't kick-in that quickly - nothing does - that's my concern. I'm taking this very seriously; it's not often I feel compelled to put pen to paper.

My argument is quite simply that it should be instant, so even if it's 400 or 300ms that's still unacceptable so far as I am concerned. That single 'stab' on the peddle in my own car scrubs about 10mph off the speed at 30mph, so if they're going to argue it doesn't matter or it's okay I fully intend to pursue a different avenue. (AA or RAC inspection?). The man I spoke to over the phone has already questioned if I know what I'm talking about. I've probably driven more cars than he's had hot diners and since before he was born. Grrrrr

I'll post just as soon as I get feedback

If this is the future of brakes we'd better have everywhere!

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The views expressed in this post are personal opinions and do not necessarily represent the views of Safe Speed.
You will be branded a threat to society by going over a speed limit where it is safe to do so, and suffer the consequences of your actions in a way criminals do not, more so than someone who is a real threat to our society.

I know it feels weird, but:

http://auto.howstuffworks.com/brake-assist.htm/printable

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The world runs on oil, period. No other substance can compete when it comes to energy density, flexibility, ease of handling, ease of transportation. If oil didn’t exist we would have to invent it.”

56 years after it was decided it was needed, the Bedford Bypass is nearing completion. The last single carriageway length of it.We have the most photogenic mayor though, always being photographed doing nothing

I can't find any suggestion in that explanation about delayinng the application of the brakes in the way Tone describes

For all the hype brake assist is merely a highly non-linear relationship between pedal pressure and braking effort.

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When I see an adult on a bicycle, I do not despair for the future of the human race. H.G. Wells
When I see a youth in a motor car I do d.c.brown

I had assumed there would be some rate of change relationship too ?

Tone,

I'm no brake expert, but I suspect the brake booster has a problem. What might give a clue is how the car reacts when the brake servo is disabled (i.e. engine off with the servo reservoir pumped empty).
This is a very risky test which requires controlled conditions and must not be attempted on a public road or other shared space, not on any form of incline, and not by anyone less than very competent (someone who doesn't know what the performance of a servoless foot-brake isn't, or doesn't know how to control a car without the foot brakes, without the power steering etc).

Someone may say this kind of test shouldn't be done outside of a proper rolling road test bed, and they may well be right

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

Whatever you do, do not forget the steering lock, if you switch off the engine make sure you turn the key back to the 'on' position.

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Driving fast is for a particular time and place, I can do it I just only do it occasionally because I am a gentleman.
- James May

Yes of course. By pedal pressure I was implicitly including rate of change. Sorry

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When I see an adult on a bicycle, I do not despair for the future of the human race. H.G. Wells
When I see a youth in a motor car I do d.c.brown

Scania trucks do this too.

Don't do an emergency stop in front of a Scania !! I wrote off a Learner because of this... 17:00 hours on the A14 Kettering A43 (corby) junction... Bobtail. Nothing coming.. learner sits there... Be patient.... Look right again... still nothing coming... Learner sits there......... look right again... unbelievable, still nothing coming... Learner sits there... Look right again.. STILL nothing coming... learner moves off...
Me.. looks right and breaks golden rule... didn't look back.. Learner had drove forward but engaged wrong 2nd gear and stalled halfway cross roundabout.

Crap delayed Scania brakes = ................ BAMMMM... Just kissed his butt on kinetics. But force writes off Fiesta.

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The Box said "Windows XP or better" ... So I installed Ubuntu

Thanks guys. I don't want to gorge the thread with my posts but thanks to everyone for your help Any and all thoughts, findings and experience are most welcome I expect the Spanish inquisition and conclusion will be some time next week but there's nothing more I can do for now. Outcast has given me hope that I'm not completely mad, so once again thanks. It's comforting to know someone else has experienced, or knows, the same phenomenon.

I have a strong feeling, speaking as a grumpy old man, that like so many other things in today's life it's about making cars stupid-proof. So when someone gets behind the wheel who actually knows what s/he is doing it's noticable that things aren't what they used to be and not necessarily for the better.

Oh and thanks Steve I don't know what a booster does or if its a known problem on this car but I hope they will be honest in their report. I will know if it's cured however.

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The views expressed in this post are personal opinions and do not necessarily represent the views of Safe Speed.
You will be branded a threat to society by going over a speed limit where it is safe to do so, and suffer the consequences of your actions in a way criminals do not, more so than someone who is a real threat to our society.

Done that once a long time ago and wet me knickers! Aint no substitute for experience

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The views expressed in this post are personal opinions and do not necessarily represent the views of Safe Speed.
You will be branded a threat to society by going over a speed limit where it is safe to do so, and suffer the consequences of your actions in a way criminals do not, more so than someone who is a real threat to our society.

I still feel there's something wrong with the car. The Scania braking system will be very different to that fitted to a car. "Response time" of Heavy Goods Vehicle can be an issue, but it shouldn't be on a passenger car. Although I've not driven that model of vehicle, I've driven plenty of other Peugeots and they don't do it!

I'm also doubtful that it will be the "brake assist" system. Thinking about it, the very last thing a system designed to give you maximum braking as quickly as possible would do is to introduce a half second delay! On Other Peugeots I've driven, it has started to act completely seamlessly - the only indication that it is working having been the fact that the hazard warning lights start flashing.

It would be interesting to know if the half-second delay is without braking AT ALL, or is accompanied by REDUCED BRAKE EFFECT (ie: SOME braking but not much)
If it has NO braking then clearly there is a problem with the system to a very large degree, a reduced effect could be due to the servo assist not having sufficient "vacuum" or even an air leak in the system.
Unless it has no vacuum servo and uses the electro-hydraulic pump......

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The world runs on oil, period. No other substance can compete when it comes to energy density, flexibility, ease of handling, ease of transportation. If oil didn’t exist we would have to invent it.”

56 years after it was decided it was needed, the Bedford Bypass is nearing completion. The last single carriageway length of it.We have the most photogenic mayor though, always being photographed doing nothing