ABS or not?

[Dave2000]

The ABS light should come on when you shift to low range and engage the CDL, odd that the light function is now correct AFTER the ABS does what it normally does i.e. 'shat itself' when on gravel, it simply gets confused. So that is all now correct, the advice about the ABS rings is good, a couple of things to do, remove and clean the sensors and clean the teeth of the ABS rings and put it all together, be gentle when removing/cleaning/installing. Another known cause associated with the ABS activating prematurely at slow speeds, is the CV spindle bearings, they allow the CV to 'run out', enough to confuse the ABS sensors, classic symptoms are, slowing to a stop perhaps for a junction and hitting a small bump or seam in the road, the ABS triggers and you get the feedback through the brake pedal.

regards

Dave

 

[Knucklehead]

think it is normal for ABS light to come on when in Low Range as abs is disabled. Does on my '93 anyhow.

Had similar issue with the brake pedal vibration when coming to a halt.
Fault codes pointed to front so ended up removing the shim under the front sensors to decrease the air gap between these and the rings.
Been good for 4 years now. Think this is only an option on the earlier 80's as the sensors changed for the later ones.


Dave.

 

[karl webster]

My 2p worth on this.

Ive obviously drove a fair few 80s in my time and I've come across abs issues a lot.

On my personal 80 I ran it as it came from factory. The abs used to do strange things from time to time as have other 80s I've been in.
I was towing an 80 I bought back home a couple of years ago when I approached an island. I touched the brake with 3.5 tonne behind me and the breaks went daft. The abs was cutting in and out that fast it wouldn't break at all. Luckily nothing was coming because I went straight into any oncoming traffic that could have been there. From that day on my abs has been un plugged and has only been plugged back in when it was sat at the test station. Soon as it was moted it was unplugged again. The abs light had never been on and there has never been anything wrong with the abs regarding faults.

i personally think its Dangerous. Much rarther have a break pedal under my foot that does what I want it to do not what a commuter what's it to do. JMO

 

[Dave2000]

Obviously a problem somewhere on the system, as per Dave's post above yours, again the sensor to ABS ring giving rise to issues with system. Or.......a point about your 'event', I had a similar thing years ago when towing my Jaguar to Santa Pod raceway for a drag meet, I was using a Range Rover owned and used as a tow barge for many years and I suppose the Jag with trailer was perhaps 3.5 ton? I had only driven a couple of miles in the rain and came to a junction, put the brakes on and the ABS activated and allowed the weight of the combination to push me over the stop line. Like you I was lucky and no accident, and so when I got somewhere safe I tried a slightly heavy braking again and the same problem car was simply not pulling up ABS was being activated over and over. I could not go up the M1 like this! I unloaded the Jag and reversed it onto the trailer, from then it was perfect! I could then brake quite heavily without ABS intervention.

The weight of the V12 engine on the tow bar was trying to lift the nose of the RR, as I tried to brake, the front wheels would lock prematurely, the ABS would intervene on and off, of course as the wheels were attempting to lock straight away the ABS released the wheels, in essence no front brakes. I have said this before, the ABS CANNOT overturn the laws of physics.

Having spent some time in motorsports I used to tow a lot of vehicles but nothing as heavy as my Jaguar, prior to then I suppose I must have used the RR to tow thirty or forty times with no incidents. The Range Rover ABS system was great when the nose weight of the trailer was near perfect, if an accident had occurred I would have had to taken it on the chin as the nose weight was simply way off. Karl, I am unsure whether you put the LC's on your trailer facing forward or backwards but worthy of note?

I don't see as many LC's as you Karl but the ones I have worked on rarely give ABS issues, normally front wheel slip sensors, and going by the amount of them out there that are not suffering failures and causing accidents it could be taken that problems are very rare.

There is also a muddying of waters here, ABS when working correctly will not be beaten in a panic situation. If there is a failure whether it be hydraulic or ecu related then of course this is a different issue, or in my case in effect user error.

BTW compiling a list of 'bits and pieces again' PM soon Karl

regards

Dave

 

[karl webster]

I've done miles of towing over the years Dave.

Always facing forward on my trailer. Nose weight for cruiser should be around 150kg.

It's personal choice I suppose.i have never liked abs in anything though. Not a nice feeling when your pedal isn't doing what it's suppose to do.

look forward to the list mate. Hope the new box is all good

 

[Dave2000]

Hi Karl, for me the Jag V12 engine alone IIRC was around 700 lbs, so I would have to call user error on my part, the RR never displayed that again when the nose weight was correct. I agree about preference the trouble is these days with modern cars, all having electronic systems we are unable to avoid unless you simply do not buy modern cars. I do not like electronics and they can do weird things, I have various test kits for Air Bags/OBD/ABS/ stability and so forth and a simple loose plug or dirty earth and the whole caboodle is useless. I do not like electronics in cars and particularly in 4x4's, especial where isolation and water is concerned.

Gearbox experimenting still going on 85% happy, won't hijack this thread so keep an eye on the thread I am running.

regards

Dave