[QUOTE=Laird Scooby;2775039]
Quote:
Originally Posted by Army
Now that really is confusing! 
Why, then, do both my cars, both equipped with ABS - Anti-lock Braking Systems - have servos from the factory? Even the Jensen FF which had a mechanical anti-lock braking system developed by Dunlop (think there may have been someone else involved too but can't remember just now) had a servo!
Also, the oldest car i've owned so far, a 1967 Rover P6 had a servo - granted it was remote living down near the headlamps if memory serves (it was 35 years ago!) but a direct mechanical link to the brake pedal and then after the servo was the master cylinder.
The servo is there to reduce the effort needed by the driver on the pedal to bring the vehicle to a stop quickly. No more, no less. |
I don't quite understand what is confusing or why there is confusion (!)
As you describe the servo / booster up until now is more often than not a different piece of the braking system.
Whilst some times a part of the ABS system is called the "pump" it isn't (in the cases I've come across so far at least!) a part that increases pressure like a servo / booster - that's the job of the servo / booster.
There's nopthing, however, to stop say electric vehicles that are going to struggle to produce vaccum naturally from using combined braking systems that not only help with the feel / effort of braking combined with some form of stability / anti-skid features.
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The point I was trying to make - which might not have come over clearly - is that there is a reason why ABS was invented.
As I am sure you know - under hard braking with out ABS the wheels can lock up and the vehicle skids. Generally speaking (ignoring drifiting and competetive driving) skidding is considered to be a bad unsafe thing (!)
When I took my driving lessons I was taught to pump the brakes to try to stop the vehicle from skidding. I assume pupils are now taught to keep their feet firmly on brake pedals these days to get the full advantage of the effect of ABS...
...in this thread my impression of the information given thus far is that ABS doesn't improve braking. In terms of pushing friction material onto the braking surface it generally doesn't help (like a booster / servo can) but in terms of bringing a vehicle to a halt under hard braking where skidding will / might happen it is a system that is intended to reduce braking distances and improve safety
[Probably wasn't necessary to be so pedantic but hey it has happened now!]