ABS Brakes on dirt roads ?

Submitted: Monday, Apr 20, 2009 at 21:15
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Just wondering if there are any problems or suggestions for using the ABS system on the Rodeo on dirt roads or off road in general?

I have heard of people installing switches to turn it off?

Does anyone have ideas or suggestions ?
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Reply By: Lenticular - Monday, Apr 20, 2009 at 21:31

Monday, Apr 20, 2009 at 21:31
Dug,
Maybe my experience can help. I have a 1998 Prado with ABS. Each Easter I go to Fraser Is, and I unplug one of the power cords going into my ABS pump. The ABS light comes on on the dash. I do this because when descending a soft sandy track with the ABS enabled, I essentially have no brakes. The ABS detects all wheels slipping and does not allow any significant braking force to get to the wheels. Raised the ol pulse rate the first time it happened- zooming down a hill with the brake pedal buried and the ABS pulsing away merrily and almost no braking.
It did not happen when I was in low range, so I drove around in low range on the fiirst trip when on the inland tracks.
I unplug the ABS now so that I can drive in high range, and can brake merrily on soft sand.
I understand that later versions of ABS may be a bit smarter now and may not be so bad. Maybe others can comment.
AnswerID: 360613

Follow Up By: D200Dug- Monday, Apr 20, 2009 at 21:34

Monday, Apr 20, 2009 at 21:34
I know the systems have got much smarter

I am just wondering how smart they are now :-)

I will be finding some dirt to test it out on soon !
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Reply By: Kim and Damn Dog - Monday, Apr 20, 2009 at 21:47

Monday, Apr 20, 2009 at 21:47
A few years back there was a similar post, and I suggested by saying ABS is a problem on dirt roads. Nearly got my head ripped off from the responses.

At the risk of getting a lot of flack, no I don’t think ABS is appropriate on tracks, particularly where spoon drains or natural obstructions are concerned.

There are times when the driver is required to make a decision, rather than rely on an all encompassing gadget.

I think it’s a good piece of technology in certain conditions, but the driver should have the choice to either switch it on or off in the prevailing circumstances.

Regards

Kim
AnswerID: 360617

Follow Up By: Member - Stephen L (Clare SA) - Monday, Apr 20, 2009 at 22:50

Monday, Apr 20, 2009 at 22:50
Hi Kim
I agree 100% with what you are saying. I personally think that they are useless on dirt roads if you need to apply the brakes in a hurry, as I have found out. For me, this is one thing that I would love to remove from my Prado.

Cheers

Stephen
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Reply By: D200Dug- Monday, Apr 20, 2009 at 22:49

Monday, Apr 20, 2009 at 22:49
Does full time or part time 4wd make any difference ?


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Follow Up By: Member - Oldplodder (QLD) - Tuesday, Apr 21, 2009 at 08:11

Tuesday, Apr 21, 2009 at 08:11
Found in the pajero , shifting on the fly from 2wd to 4wd does make a difference to braking. Especially on wet bitumen and dirt roads.
With 4wd high and the centre diff engaged, whether it be the viscous coupling in 4wd high for bitumen and good dirt, or with the centre diff locked on loose dirt and sand, I don't get front lock up in heavy braking.
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Reply By: Malleerv - Monday, Apr 20, 2009 at 23:25

Monday, Apr 20, 2009 at 23:25
I do not have a vehicle with ABS and have not driven a vehicle with ABS to the point where I needed to use the ABS so I have limited experience in first hand accounts and I can understand Lenticular's reason for disconnecting it on steep tracks and the like, BUT

I cannot understand how anyone thinks they can outbreak an ABS equipped vehicle with a conventionally braked vehicle in normal road and driving conditions be that wet,dry,dirt,blacktop.

Am I missing something in regards to how they react or work in everyday driving conditions??
AnswerID: 360633

Follow Up By: D200Dug- Monday, Apr 20, 2009 at 23:37

Monday, Apr 20, 2009 at 23:37
On a dry bitumen road normal brakes will stop you quicker than ABS will. It is just simple friction, lock up the brakes and maximum friction will cause the fasted stopping distance. What ABS allows you to do is keep control of the direction of the vehicle and steer while applying the brakes. So hopefully avoiding an accident. They also prevent aquaplaning in wet conditions so usually stop quicker in wet conditions while still allowing steering control.

I just wonder about how they cope when the road surface moves under the wheels :-) Conventional braking on dirt or sand builds up a ridge in front of the wheels causing them to dig in and stop, sometimes very quickly !

I was just wondering what difference ABS would make.

PS I will be going out and slamming on the anchors on a clear empty and wide dirt road soon to make sure I DO know what happens.
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Follow Up By: Malleerv - Tuesday, Apr 21, 2009 at 00:03

Tuesday, Apr 21, 2009 at 00:03
My understanding is that once the wheels start to skid maximum friction is lost in the skidding effect. With the wheels no longer gripping to the road but sliding over it this generates less friction.

I understand what your saying but my understanding is that ABS prevents the skidding not only for steering control but greater braking ability. Not all dirt roads will build up a ridge in front of the wheels, well certainly not around here. Even after the roads are graded you wont build up enough material to assist the breaking and the road surface is to hard to penetrate in a skid.

Matt
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Follow Up By: D200Dug- Tuesday, Apr 21, 2009 at 00:14

Tuesday, Apr 21, 2009 at 00:14
maximum friction is obtained by moving a stationary object across a stationary surface. Hence the heat generated in the cloud of rubber smoke from a burning tyre screeching to a halt. Newtons second law I think. energy is not lost but converted from one form to another.

The energy of a moving car is converted to heat energy by the friction :-)

This only works on dry solid surfaces !!!!!
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Follow Up By: Patrol22 - Tuesday, Apr 21, 2009 at 06:20

Tuesday, Apr 21, 2009 at 06:20
That is a very basic interpretation of the laws of physics guys but right to a point. However, heat and skidding is the very reason that an ABS equipped vehicle will outbrake and non-equipped vehicle on any surface. They prevent overheating and skidding and bring the object in motion to a stop much much quicker. These types of devices have been used in aircraft for more than 40 years that I know of (the mechanical versions used to be called Maxeret Units) and worked like a marvel in pulling aircraft up on very short runways without skidding of lost of control. Today's electronic ABS are a long way ahead of these.
I have ABS on my D40 and have never experienced the sorts of issues you are talking about. Not say you didn't just that I haven't.
Cheers
Pete
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Follow Up By: Member - Stephen L (Clare SA) - Tuesday, Apr 21, 2009 at 08:06

Tuesday, Apr 21, 2009 at 08:06
Hi Guy's
ABS works fine on the Black Stuff, but useless on dirt, as I know personally. A number of years back, one of our Elders Reps here in Clare was visiting one of our local farms in the area, a place that he has to been many times.
The only difference with this visit, was it was in a new Ford with ABS.
The tight approach into the farm was through two very large strainer posts, then up his driveway. Coming down the dirt road at the speed that he had travelled many times and knowing when he must apply his brakes to slow down and pass safely through the two posts, he applies the brakes, with that very strange feeling that he was not going to slow right down before going through. The end result, still two much speed before entering the property and one new Falcon written off and one strainer post still in tact.

Any person that drives constantly on dirt roads will know this feeling that I am talking able, and it is not a feeling that makes you rave about ABS.

Cheers

Stephen
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Follow Up By: Malleerv - Tuesday, Apr 21, 2009 at 08:36

Tuesday, Apr 21, 2009 at 08:36
D200Dug,

Your explanation of a cloud of smoke from a skidding tyre is the exact point I am talking about.
Take F1 racing for instance. if they come into a corner too hot and lock a brake this is never seen as a good thing and quite often other cars around them will out brake them and make a passing move. And how often do you see a race car that has all brakes locked seem to pick up speed.

Also if two surfaces slipping like you are saying generates the most friction why is a slipping clutch not a good thing! It is the same principle but in reverse to braking.

Stephen L,

Was it the ABS that made him hit the post or that he may have lifted his foot off the brake pedal when it started to pulse not knowing what was happening. Can be a catch for new players.

Not looking for arguments just facts

Matt
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Follow Up By: Member - Nick (TAS) - Tuesday, Apr 21, 2009 at 08:44

Tuesday, Apr 21, 2009 at 08:44
Have to disagree with the above comment about locking wheels to achive maximun braking power.Once wheels are locked, you increase braking distance.To stop in the shortest distance you need to apply as much pressure to the pads WITHOUT locking the wheels.Just jumping on the brakes is the most in efficiant way to stop quickly, you tend to just lock up.If you apply the pedal slowly and firmly you can apply three times(from memory) the pressure to the brakes without locking.
Its a hard thing to learn as we usually in a panic just slam on the brakes but with practise it works and works well.
I have to say Ive never locked a wheel in our ABS equiped cruiser but had plenty of slow down quickly moments on dirt road.No dramas.
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Follow Up By: Member - Stephen L (Clare SA) - Tuesday, Apr 21, 2009 at 09:11

Tuesday, Apr 21, 2009 at 09:11
Hi Matt
As far as we know, the rep used to go at a reasonable speed up the dirt road, apply reasonable pressure to the brakes, slow right down then go through the posts. With his new Falcon, he was doing the same speed, hit the brakes as usual and kept going and did not slow down like standars brakes, ending up in the middle on one very large strainer post, hit at speed.

As for my cases, it has been while travelling on dirt tracks and coming upon washaways. With our old Pajero, I had come across this situation many times, hit the brakes and stop before the washaway.
The first time in the Prado, hit the brakes and then hit the washaway. This has happened a few times and I find the best way to ovoid this is to hit the brakes and keep the foot off of the clutch and just about stall the vehicle, only putting in the clutch at the very last moment.

Cheers

Stephen
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Follow Up By: Malleerv - Tuesday, Apr 21, 2009 at 11:16

Tuesday, Apr 21, 2009 at 11:16
Thanks Stephen, as I said in my first post I have no real world experience with hard braking in a ABS vehicle so my understanding of the system is only from literature on the system operation (I am a mechanic and like to study how and why a system works like it does ).

Interesting to here your experience in your Prado and your driving technique. When braking heavily I never depress the clutch pedal unless it is to change gear which is usually at the end of the braking event. I was taught that the drive line should never be disconnected in such an event in case there is a need to power on to avoid a situation, same goes for putting the gears into neutral.

Cheers Matt
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Reply By: Member - Ingo57 (NSW) - Tuesday, Apr 21, 2009 at 09:58

Tuesday, Apr 21, 2009 at 09:58
G'day Dug

There are a couple of ways of disabling the ABS one is simply a switch but for Insurance issues nothing is more simple as finding the ABS fuse and putting a blown fuse in its place when going off road.

I asked the very same question last year after I almost come unstuck on the Hay River last year due to the ABS going beserk and not allowing me to partially lock up the wheels, now for any touring on dirt I slide in a blown fuse to deactivate it....ABS light comes on dash so you dont forget.

Hope this helps

Ingo
AnswerID: 360669

Reply By: DIO - Tuesday, Apr 21, 2009 at 10:09

Tuesday, Apr 21, 2009 at 10:09
Any (ANY) modification(s), unless approved to ADR standards, that change/alter/modify any aspect of your vehicle from the ADR standards/requirements that existed at the time of manufacture of your vehicle are ILLEGAL. Substantial penalties apply. I would be extrememly reluctant to suggest that anyone modify their vehicle's brakes by turning ABS off. Bad advice.
AnswerID: 360672

Follow Up By: Member - Beatit (QLD) - Tuesday, Apr 21, 2009 at 10:50

Tuesday, Apr 21, 2009 at 10:50
G'day DIO,

You are right about this and the possible problems this may represent for any insurance claim should there be a prang with this stuff disconnected. However, for practical purposes the argument favours no ABS on dirt tracks. Having had a couple of experiences with emergecy braking on dirt I can tell you that it is a hindrance when all you want to do is stop in a hurry. Locking the brakes is not an option and the price may well be a preventable collision say with a cow (like I almost did).

I'm no engineer so there may be an argument that sliding to a stop is no quicker than a controlled ABS assisted emergency stop on gravel. In our emergency it certainly didn't feel that way.

Kind regards
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Follow Up By: OzTroopy - Tuesday, Apr 21, 2009 at 12:55

Tuesday, Apr 21, 2009 at 12:55
Baaahaaahaaaa .....

30yrs ago we were fitting extra tail lights in roof racks ... for better visibility in dusty conditions ... and then getting booked for them when out on the coast in so called civilization.

Now high level tail lights are an ADR requirement ....... pfffffffft

Take your rules and shove em DIO ... or get them changed to suit reality scenarios.




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Follow Up By: Member - Mike DID - Tuesday, Apr 21, 2009 at 20:08

Tuesday, Apr 21, 2009 at 20:08
In the 60's when European cars were imported, the Hazard Flashers had to be disconnected as they were illegal.

Then they became compulsory !!!!
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Reply By: D200Dug- Tuesday, Apr 21, 2009 at 11:12

Tuesday, Apr 21, 2009 at 11:12
Thanks for all the info I think the obvious decision is to "Suck it and see" there are obviously differences in the braking systems between vehicles so there is no absolute right or wrong answers to this question.


Thanks for the input I will let you know how we go when we test it out . Given that we get home OK and in one piece :-)
AnswerID: 360679

Reply By: OzTroopy - Tuesday, Apr 21, 2009 at 13:00

Tuesday, Apr 21, 2009 at 13:00
Going by comments and bypass modifications on vehicles on other forums .....

Any computer control affecting wheel action / throttle control is making sand etc more difficult to traverse.

Read where one person was told by a dealer that their vehicle wasnt safe to leave the workshop coz the electronic suspension module was malfunctioning ..... pfffft ... the mechanic obviously needed to go for a drive in an old falcon station wagon to understand dangerous suspension ... LOLOL
AnswerID: 360686

Follow Up By: Lex M (Brisbane) - Tuesday, Apr 21, 2009 at 13:58

Tuesday, Apr 21, 2009 at 13:58
OK, but in this cotton wool wrapped society in which we now live, the dealer had a "duty of care" to do that and not doing so could be very costly to him.
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Follow Up By: OzTroopy - Tuesday, Apr 21, 2009 at 14:16

Tuesday, Apr 21, 2009 at 14:16
Even prior to our cotton wool society they had a duty of care ... so agree totally Lex M

I guess what Im getting at ... is that a vehicle someone paid $quillions for ... is rendered unusuable and a waste of space/money for days or weeks ... because of an "unnescessary" component that should be an optional extra and / or be able to be bypassed.

Or .... Is it possible that new vehicles designs are so bad these days .... they are dependant on electronic over rides ????
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Follow Up By: Geoff (Newcastle, NSW) - Tuesday, Apr 21, 2009 at 14:59

Tuesday, Apr 21, 2009 at 14:59
It doesn't even take a malfunction to render a vehicle useless.

I know a young bloke who owns a stock standard Jeep Patriot, at least the Patriot bit is what it says across the back bumper bar.

He was told his warranty on exhaust and under body would be void if he drove on the beach as they'd already replaced too many exhaust systems due to beach driving.

Modern pffft, bloody Westfield low riders. I wonder if Westfield speed humps are actually covered?

Geoff

Geoff,
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Follow Up By: Lex M (Brisbane) - Tuesday, Apr 21, 2009 at 15:58

Tuesday, Apr 21, 2009 at 15:58
"Or .... Is it possible that new vehicles designs are so bad these days .... they are dependant on electronic over rides ????"

No. Just the drivers.......
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Reply By: Member - Matt (Perth-WA) - Tuesday, Apr 21, 2009 at 15:00

Tuesday, Apr 21, 2009 at 15:00
Doug, the benefit of ABS isnt just shorter braking distance it is CONTROL of the vehicle as well. By not allowing wheels to lock you retain the ability to steer the vehicle under all driving conditions.

Before any one can reccommend if ABS is or isnt a benefit to your driving 'off' road...they would first have to look at the infinate amont of variables as to what ascertains 'off' road.

There are a very limited amount of times when ABS could be seen as a disadvantage to the vehicles control and low range is about the only time when you could agree that it could be turned off.

Hence why many maufacturers do just that.

On hard packed dirt roads, pea stone gravel etc...steering is still one of the most important factors and rather than relying on locking up the brakes and hoping to stop in time....ABS will stop you but in the meantime allow you to steer around the obstacle or bend or camber in the road.

Whats the point in locking the wheels to have the camber in the road steer you off into a tree....stopped quick though!!

I can show you ABS training videos in arctic ice road conditions where trucks are tested with and without ABS and while some vehicles can stop quicker without ABS the three 360 deg revolutions they did before coming to a halt would not be fun. The ABS trucks did stop in a long distance but were able to retain control and steer while braking to make a safe stop.

There are too many surfaces to say when and where the ABS should be used for but to keep it simple anything in Low Range should be the only exception to ABS if the vehicle is equipped and not disabled in manufacture.

Additionally ABS nowdays is also incorporated into the traction control and other vehicle stability systems. So by having the driver overide it...you might be in more trouble than you realise.

My opinon anyway.

Good luck
Matt.
AnswerID: 360701

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