Thread: Switch to turn off ABS for off-road use???

Originally Posted by davros

... We've got a lot of information on the pros and cons of turning ABS on/off but I get the impression no one has actually deliberately done it apart from "accidently" when using the cdl?
Iv'e just attempted the "10 pumps of the pedal" trick mentioned in the link to no avail on my 2000 disco two.
Does anyone know the answer to my previous question - if you remove the fuse, will it activate/deactivate the ABS without having to restart the vehicle? And I guess if you stop with the fuse "out" when you restart can you just put it back in without resarting? My guess is no as per using the CDL... ?? (ie would a switch on this line be a simple "on/off" job or stopping and starting?)
Its rarely I'd turn off the ABS but if it's going to be a hassle I'd rather it on than off, but so saying it can be a bit hairy using ABS on loose gravel or slimy mud. It's great to be able to steer as people say but only when there is somewhere to go! At other times I'd rather just stop! (example - rounding a corner on a "closed in" track to find an unexpected gate or fallen tree).

On another note - as we're all putting our two bobs in about braking - here's some info and a few ABS questions:

Cadence braking ("pumping" the brakes) is best for drum brakes, or so i'm told. This is because drums do not tend to release well if you just lift your foot a tiny bit, and to get the wheels tuning again must be released a lot whereas...

Threshold braking (pushing pedal till tyres lock then releasing the brake pedal gradualy untill wheels start to turn) is better suited to discs, which will respond better and release quicker when the foot is lifted.

So saying, after getting used to both, what happens with ABS? If the wheels lock up and the modulator kicks in, does it matter how hard you stand on the pedal? Are the "modulations" strength related to pedal pressure?
My automatic reaction in a skid is to lift my foot (as with either cadence or threshold braking), with ABS should I do this or just stomp on it?I believe the latest landies have a "emergency braking" response in the ABS that I guess equates to stomping on the pedal??
Question questions...

STOMP!

I had this discussion with my (now ex-) wife when she almost totalled our Subaru into the side of some dill's ute (he pulled out in front of her). She was very proud of the fact that the car didn't skid but no, the brake pedal hadn't pulsed. Since I'd tested it out I knew exactly what the ABS did, including the thumping back through the pedal.

AFAIK, once you reach the threshold (skid) it makes no difference whether you are heavy or light on the brakes, because from then on the computer is optimising the braking response. And it will pull the vehicle up faster than you will if you lift your foot. Unfortunately, it's completely counter-intuitive to an experienced driver.

I'm trying to get my wife to come out and do some braking practice, so she'll know what to expected.( Its our first ABS equipped Vehicle) Its very unnerving the first few times.
Once had a Guy swear black and blue that when you feel the ABS pulse that you should lift off. Didn't matter what was said by me or others, he'd done a one day advance driving course, with 20 of his work mates.

Yes longer braking on hard surfaces, but not always on gravel/dirt surfaces.

below is cut and paste from the Wabco site. and is very much what I have experienced( except the "slightly longer" in my case has been "alarmingly inefficient". This is why I would like to switch the ABS off on dirt roads, because it is not always practicable to "drive slowly and with the utmost of care" Of course I am not advocating race style driving just reasonable cruise speed.

"Despite the above, you should not
expect that ABS will reduce the braking
distance under all circumstances.
The braking distance may even be
slightly longer when driving on gravel
or new snow on a slippery base (grit/
snow wedge) when in any case you
should only ever drive slowly and
with the utmost care."

Driving on unconsolidated ground

• Actuate the brakes carefully
when driving on surfaces with a
soft, deep covering such as in
deep powder snow, sand or
gravel. The braking distance may
be longer under certain circumstances.
Under such conditions,
the braking distance may be
shorter if the wheels lock up as in
a system without anti-lock brakes
(due to the wedge of material

which forms).

Originally Posted by numpty

I think you've just answered your own question. ABS actually brakes and releases (cadence braking) only it does it many times faster than the human foot can. I always practised cadence braking on drum brake equipped vehicles and force of habit has me doing the same thing with disc brakes. And my Defender is ABS equipped. In my opinion, (and that of advanced driving instructors I've dealt with) skidding wheels mean no control and longer braking distances.

Just like to comment how good this site is for "down to earth" experienced opinions without too much "soapboxing" (although a little is good as it keeps me on the straight and narrow - and around a few corners too!). I guess the conclusion to this thread is - as we seem to have no real results of mods to ABS systems [which sound rather risky in nature, something that really appears almost as much fun as "lets play with the airbag actuators and then run into a tree and see what happens"] - that ABS is not great in all circumstances but in the majority of high speed situations, especially on firmer roads with somewhere to steer too, it will be an advantage.
For the inexperienced I'd say leave well alone!
For the off road extrememist, I'd say have fun but don't bother calling your insurance company when it all goes-pear shaped!
Now, where's those wire cutters and a switch...

Dave
PS remember to STOMP!!