Thread: abs shudder under descent or slippery dirt

Sounds normal. As the wheels slip the ABS may release/grab. My D1 was terrible on loose gravel, corrugations and in mud. Could be bloody terrifying sometimes.

Originally Posted by dm_td5

Sounds normal. As the wheels slip the ABS may release/grab. My D1 was terrible on loose gravel, corrugations and in mud. Could be bloody terrifying sometimes.

really .....your right its bloody scary sometimes it never fails just ..shudders...i guess ill just get used to it ...

cheers

mine does it in the disco to the point were it doesn't stop so great.......I once had to pull up the hand brake when coming to a junction....it went in and out of the garage and no one ever found a problem with it.

I will eventually just put some good slotted rotors on and some good pads...

Not had a problem with it for ages though thinking about it

My record (that I measured) was over 400m to pull up on a dirt track. We were probably doing about 50-60kph and I didn't think we were ever going to stop. Once we did I turned around and measure the distance on the trip.

The ABS will shudder on a bitumen road too if you jam it on. Find a nice open, straight road with no one around and try it one day.

Mine also does the same (also same spec vehicle). Takes a little while to get used to as my D2 had better brakes.

Off road its even worse on downhill descents, slight touch of the pedal & the shuttles valves do their thing.

Cheers

this from our slightly ****ed off workshop guru,when he was constantly asked why the brakes shuddered,not that far off course though





Subject: SAFETY SAFETY SAFETY
Good afternoon to everyone form you friendly Fleet Manager,
As the wet season has begun to arrive I have received some complaints about vehicle brakes not working or there is something wrong with the vehicle brakes.
Nearly all of councils light Vehicle Fleet is fitted with Anti-Lock Braking System (ABS)
Many of the Councils medium trucks are also fitted with ABS. Soon Heavier Vehicles will also come with ABS standard.
Anti Lock Braking system is just that.
It is a system that prevents the wheels from locking up under certain braking conditions.
Why. Because once your wheels have locked up and are skidding you no longer are able to control the steering of the car and there is a loss of braking effort once traction is lost. In short we have ABS so you don't lose control in unusual braking conditions
To the uninitiated it will seem that there is something horribly wrong with the brakes.
Some people have actually died because they had not experienced ABS when it works, and they took their foot off the brake.
When the ABS begins to work, the symptoms are;
1. The brake pedal will feel like it is going to the floor. Its not (this is when people have taken their foot off the pedal)
2. The brake pedal will begin to give a rapid pulsating kick back through the pedal.
3. You may experience a shuddering in the front of the vehicle under brakes,
4. There is the likely hood of horrible sounds coming from under the front of the car

What is happening?
1. The computer has determined that there is a difference in the speed at which the wheels are rotating in relation to each other and the vehicle road speed.
in simple terms one or more wheels are about to lock up and skid under the braking effort being applied.
2. The computer then releases the braking pressure being applied to the wheel that is about to lock up and re-applies it again. This occurs very quickly, this is the pulsating in the pedal
3. The rapid release and re-application of the brakes causes the front end to shudder and in some cases make a noise.

During the wet season ABS works more often than people realise.
There is no doubt that ABS may take a bit longer to stop but you don't lose control. This means that you can avoid hitting objects that could bring you to an undesirable sudden stop. Instead you can steer around them.
If the ABS is activating there is a good chance that you were actually not driving according to the road conditions. This becomes more pronounced during the wet season as it easier to lock up a wheel on a wet road.
Whilst knowing all this is good there is no substitute for real experience. You can know about it but the knowledge is incomplete until you have experienced it.
To that end Training for council employees is being sourced and there will be more information on this when it becomes available.
Drive Safely stay alive.

yeah thats exactly it lewy......

problem I had mine came on when pulling into driveways hardly the need for abs I think.

oh and pulling up to junctions when i wasn't even going over 40

It has frequently been shown that ABS means it will take longer for you to stop on gravel roads BUT you will stop in control When the wheels lock up gravel builds up in front of the now skidding tyre and helps to stop the car but there's less chance of you being able to do this in a controlled way. We have a fair bit of dirt road to drive each day and I've only ever had to use the ABS in anger once but I was glad I had it

It is scary though the first time the pedal starts to do its thing

Andy