ABS off on steep terrain?

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Witbobbejaan
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ABS off on steep terrain?

Post by Witbobbejaan »

Hi All

I have a steep little hill (maybe 50m) long,on tar, on my daily drive. Driving it down hill. Stop street at base, T-junction, other lanes no stop signs. Always a tiny bit of gravel on it. Maybe 20-40 degrees slope? I don't know. Anyway needless to say I never really get up to much speed there. 2nd to 3rd gear, sometimes "freeing it". The thing is I usually have to brake sharply at the very end of my brake sequence, to stop in time. More often than not, the ABS kicks in, and I slide quite precariously and sometimes even over the line (no cars fortunately). This is the only place I encounter this. It's a disconcerting feeling & drives me nuts.

SO this got me wondering if anyone out there ever disengages their ABS (somehow...fuse removal?) in steep offroad terrain, say dirt road with gravel, to try and stop the ABS kicking in and sliding the vehicle when pushing down hard on the brakes?

Comments?

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Re: ABS off on steep terrain?

Post by Dewald »

Good evening Dion.

It doesn't sound right, the Abs is supposed to prevent the sliding as it should keep the weels turning.

If you say the Abs kicks in, do you feel the brake pedal starting to pulsate / vibrate under your foot?

If you remove the Abs fuse you will cuase it to slide as the wheels will lock and then you can loose steering ability also, as soon as your front wheels locks and slides you can turn from left to right without getting the vehicle to actualy turn, it will only turn once the wheels start roling again after the brake is released

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Re: ABS off on steep terrain?

Post by Witbobbejaan »

Hi Dewald. Yeah, the brake pedal pulses. But because of that the vehicle takes longer to stop...it doesn't stop sharply and I think because there is gravel underneath, the wheels slide inbetween the brake pulses?
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Re: ABS off on steep terrain?

Post by mvcoller »

If you think it takes longer to stop with the ABS engaged, you will find it takes even longer if ABS is disengaged.

The problem is the steep road and the road surface in conjunction with the vehicle weight.
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Re: ABS off on steep terrain?

Post by Dungbeetle »

I sort of agree with the posts but, you can experiment by switching on difflock just before that spot and off again after. Not sure about your Patrol, but mine switces off ABS and does NOT engage difflock if not in 4x4. I use this often on very corrugated dirt roads, where ABS can be very annoying.

Or if you still have your auto hub lockers in front, simply select 4x4 high on the fly in that area only, that is if you do not need to turn very sharp on the hard surface

Also, when last did you clean your wheel speed sensors and pickup rotor area, if they are clogged with stuff such as brake padd dust etc. the ABS kicks in too soon and works erratic
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Re: ABS off on steep terrain?

Post by Witbobbejaan »

Dungbeetle wrote: 12 Oct 2023 05:36 I sort of agree with the posts but, you can experiment by switching on difflock just before that spot and off again after. Not sure about your Patrol, but mine switces off ABS and does NOT engage difflock if not in 4x4. I use this often on very corrugated dirt roads, where ABS can be very annoying.

Or if you still have your auto hub lockers in front, simply select 4x4 high on the fly in that area only, that is if you do not need to turn very sharp on the hard surface

Also, when last did you clean your wheel speed sensors and pickup rotor area, if they are clogged with stuff such as brake padd dust etc. the ABS kicks in too soon and works erratic
Insightful points :salute: Yeah I've never cleaned those while I've had the troll :redface:

So to be clear: you turn your ABS off, by turning Difflock on, while in 4WD? or while NOT in 4WD?
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Re: ABS off on steep terrain?

Post by SJC »

Witbobbejaan wrote: 13 Oct 2023 19:49
So to be clear: you turn your ABS off, by turning Difflock on, while in 4WD? or while NOT in 4WD?
While in 2wd. In 4wd difflock would engage.
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Re: ABS off on steep terrain?

Post by Witbobbejaan »

SJC wrote: 13 Oct 2023 21:06
While in 2wd. In 4wd difflock would engage.
So in 2WD you turn on Difflock...but it doesn't actually engage...and the ABS doesn't know the difference?

This feels like a loophole in a contract :rolling:
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Re: ABS off on steep terrain?

Post by Dungbeetle »

Like I said, dunno about yours, and date I say others. But I followed the wiring diagrams and there os a circuit running through the led indicators of 4WD, Diff Lock and ABS. Seems likie ABS switces off if either 4WD or Difflock comes on, so in 4WD and/or difflock is switched there is no ABS, meaning no 4WD but difflock no ABS
Plus if no 4WD light but difflock swtched on, led flashes, no ABS and no 4WD

Eish if that paragraph makes sense I deserve a Bells, anyway ir works as I said for sure
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Re: ABS off on steep terrain?

Post by Dewald »

I agree with Rudolf the diff lock will overide the abs, thats when the abs light comes on together with flashing difflock light and the diff lock doesnt turn on if not in 4wd and also not above 7 km/h, its a safety feature of it.

When in 4wd and below 7km/h the difflock will engage and then there is a warning chime when going past 20km/h with it engaged however it stays engaged until switched of and shifting back to 2wd.

I also think the weight plays a big part and maybe the abs is not as refined as the newer vehicles, meaning the time between braking and releasing and breaking again might be a bit longer so that combined with going downhill, the loose surface and weight of the Patrol its probably likely to struggle to stop in that situation.

Would be interesting to hear what you find when doing some testing.

Regards
Dewald
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