Left Foot Braking = Hesitation?

[JayBee75]

Potentially I am identifying a common nuance with the D4, and whilst I think it’s dangerous I wanted to understand how people “drive” around the problem. If I touch the brake at any point whilst my foot is also on the accelerator the car hesitates for 2-3 secs (seems like an eternity) then clear itself and accelerates. I know the hesitancy problem has been discussed before, but I am trying to establish whether it’s all the same thing.

The problem for me is based on my motorsport background I am a left foot braker, as well as when 4wding proper technique would be using both feet to operate both pedals it tight and difficult situations. Likewise when in carparks or reversing up driveways or trailers I find using the on and off method with left and right foot, gives much better control of the car. Problem is the minute there is even a slight cross over the car hesitates for those few seconds hence either removing control from you, or placing you in a dangerous situation in the middle of traffic (has occurred a few times).

Is this a characteristic of the D4 and live with it, or is it something that can be improved? For me it’s very odd, even after 10k’s of driving it, and I hazard a guess is actually a behavioral aspect of the ZF 6 speed?

Welcome any input or thoughts.

Thanks
JB

[BigJon]

I suspect it is programmed in to prevent left foot braking from loading up the torque convertor / transmission.

[mylesm]

could also be a crash prevention technique,

i.e. jamming your foot on the brake and half on the accelerator in an emergency by accident, therefore it cuts the accelerator.

maybe

[superquag]

Long story as to 'why'... but I'm relieved to see another driving technique heretic ! I find it safer in traffic - shorter reaction time and more control when reversing.

My Classic's 4 spd ZF does'nt do any of the above, so I'd guess its a function of the engine/gearbox management systems, such as the programming engineers never forseeing such sacrilege. But then again, mine's a technological dinosaur compared to D3/4....:angel:

Or a glitch...:(

[jimc]

I understand that (probably wrong) when you press the brake, the CAN bus tells the ECU to ignore all accelerator input...at least that is what happens with my diesel VW.

This could explain why you see this effect. However I frequently "drive through the brakes" when offroad, so suspect it is speed sensitive, or terrain response sensitive.

[gghaggis]

It is a characteristic of the car - designed to act that way.

LR's philosophy is that the electro/mechanical aids in the vehicle do not require the use of simultaneous braking and acceleration whilst off-roading. There is no requirement to "overload" the diffs due to the TC/TR, and HDC/DSC takes care of the rest.

Cheers,

Gordon

[BMKal]

Mine's a 2012 D4 six speed and I haven't seen this "delay" at all. I don't normally use left foot braking, but have done occasionally in tight parking / manoeuvring situations, and have also been known to occasionally sit at the lights with left foot on the brake and right foot with slight pressure on the go pedal for quick get-away. Have never noticed any delay or similar issues when doing this.

[JayBee75]

[QUOTE=superquag;1959226] I find it safer in traffic - shorter reaction time and more control when reversing.


QUOTE]

It's actually the correct way to drive and something that is not taught to the masses, yet funnily enough is in hi performance and skid pan driving techniques. Application of the brake can shift weight transfer, steady a car, balance before braking, or provide a gradual weight shift rather than sudden when undertaken correctly, even whilst accelertaing. It actually becomes a habit.
I actually left foot brake in a manual, except for when coming to a stop.

Much safer in traffic, cuts reaction time by over 50%, I find it very useful in carparks, and when in busy intersections and you need to react quickly. trying to reverse the car last week with a tonne of wood in the back up a hill proved quite difficult as I had to balance the cars movement on the accelerator whilst in a tight position.

[JayBee75]

It is a characteristic of the car - designed to act that way.

LR's philosophy is that the electro/mechanical aids in the vehicle do not require the use of simultaneous braking and acceleration whilst off-roading. There is no requirement to "overload" the diffs due to the TC/TR, and HDC/DSC takes care of the rest.

Cheers,

Gordon

Thanks Gordon, makes sense then from a 4wd perspective however on road even the slight brush of the brake at the wrong time Proves to be quite dangerous. I have actually done it by accident and have been left stranded in the middle of the intersection. I am not “loading” the brake and accelerator at the same time, actually it’s a smooth transition between the two, the cross over in most circumstances is nil, however the movement between two pedals seems to need a particular amount of gap between the two (approx 1 sec)

[BobD]

If its happening a lot with minimal overlap it could be that the brake light switch is on the way out. This is the first symptom that there is a problem with the switch and after a whle the car finally spits the dummy and won't drive at all because it thinks the brakes are on.

When it starts failing it usually manifests as a delay when turning corners after removing your foot from the brake, even for right foot brakers like me.

Bob

[JayBee75]

Thanks Bob, but the D4 is only 10,000k's old!

[Geedublya]

I used to left foot brake all the time both to balance the car and to stop, then I
bought a GT diesel Golf which didn't allow such behavior, after three years I got a D3 and now a D4.
I remember being mightily displeased with the Golf. I didn't even realise the Landrover didn't allow it either.
Until I read this post I had forgotten that it used to be the norm for me.

[gghaggis]

It may not be failing - just adjusted incorrectly.

If all is working correctly, transition braking isn't considered necessary in a D4, as the DSC and ABS should correct any abnormal trajectories. On the RRS, you could have the Dynamic Handling option which goes further with this approach.

Not saying it's any better than an advanced driver, but that's how the systems have been designed. It's not a Lotus ;)

Cheers,

Gordon

[discotwinturbo]

I understand that (probably wrong) when you press the brake, the CAN bus tells the ECU to ignore all accelerator input...at least that is what happens with my diesel VW.

This could explain why you see this effect. However I frequently "drive through the brakes" when offroad, so suspect it is speed sensitive, or terrain response sensitive.

With my Touareg I can load it up while foot on brake, and put on throttle which gives it mighty quick getup and go, but if I was cruising along with foot on throttle then hit the brake pedal it will cut engine power.

I can do exactly the same with my D4.

But when I am reversing the D4 I can have foot on the brake while using the throttle....which is also the same with my Touareg.

I guess that's the way it is.

Brett....

[phl]

Could also be part of the problem I mentioned in you other thread. Often coming into a roundabout, especially down a hill close to home, I'd brake, check to see if it's clear, the accelerate away. Quite a few times nothing happens, so much so that once a Pajero entering, after me, felt like it was about to rear end me. Then the power came on, and I was away. Real scary. So far haven't seen that with the update. But with brake pedal, could also be a fuel economy measure, having seen many people ride their brakes driving around.

[theresanothersteve]

Sounds like hill start assist technology to me, encountered it in another European vehicle.

Its there because cars are designed for the lowest common denominator in drivers, and some people cannot coordinate the handbrake and accelerator to complete a hill start.

So, when you take your foot off the brake the electronics hold hydraulic pressure long enough for your foot to apply throttle pressure.

You'll have to stop driving the D4 as if its a kart! :o

[jonesy63]

Thanks Bob, but the D4 is only 10,000k's old!

The brake switch in my D4 failed at 11,000km. :o

I now carry a spare all the time.

[BobD]

The brake switch in my D4 failed at 11,000km. :o

I now carry a spare all the time.

Mine failed around 80,000km and was fixed under warranty. I also now carry a spare with me. There is no hesitation now but there was significant hestitation after slowing using the brakes for many months before the final failure.

Bob

[Barryp]

My LR3 and now 2011 RRS both do it.
Until I understood what was going on it was quite disconcerting.
I thought that I had an engine issue initially.
Regards
Barryp

[jonesy63]

I looked at the D4 owners manual last night (IIRC, page 88) - first page on "Brakes". First thing mentioned are the warnings. First warning was (paraphrasing) "don't drive with your foot on the brakes". Now while you could read that this is just to cover people riding the brakes while driving, it also covers left foot braking.

[Barryp]

My issue was not riding the brakes which is strictly a no no, but simply brushing the pedal as you moved your foot, It is very sensitive, try it. (Maybe its my big feet! ha! ha!)
Only happened a couple of times but disconcerting at a roundabout with an unexpected power delay.
Regards
Barryp

[SuperMono]

Same with my D3 and I'm sure plenty of modern cars.
I jump between multiple vehicles, the 2 driven most frequently are small capacity petrol turbos and are setup for left foot braking, responding well to minor adjustments via mixed pedal input.
Although I'm well aware of this in the D3 it still catches me occasionally.

I haven't noticed it off-road so suspect low-range selection and/or lower speed might change the tolerance to some brake pedal.

[Davehoos]

hill start assist?

I got the p big time with the 5 cyl ranger-stalled it at every roundabout or up hill intersection.it has a traction control button you turn off.

sometimes it would lock the brakes other times it didn't.the worst time is reversing into a shed with trailer.

some drivers didn't know it was there-it shows up with your driving style.

[JayBee75]

So the brake switch was faulty they have replaced it (10,000k's), much better. Whilst you still have to be careful with the left foot braking, it was more how sensative it was even if you accidently lightly brushed the pedal the car would loose all power, now it's fine.

Spoke with LR, turns out that the brake overides the accelerator, a safety thing.?

So when I asked abour reversing trailers etc up hill (which i have to do at our country property) he said engage low. seriously? Just cannot reverse a trailer normally. Whilst technology is good in some instances, it unecessarily complicates in others.