In a message dated 01/19/2000 7:02:04 PM Eastern Standard Time,
bkrueger@ici.net writes:
<< The ABS would not allow the brakes to come anywhere near locking up. The
pedal
was against the stop and the car just wasn't stopping. There was no pulsing
going on at all. Remember, the action of ABS is to relieve braking pressure
when the system senses that the brakes are about to lock up. >>
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As I understand it, ABS relieves pressure in the brakes lines AFTER the
wheels lock up. There are wheel sensors that read the speed of the wheel,
and if it stops, the ABS pump dumps some of the pressure to keep the wheel
turning. Some cars have sensors on all four wheels, some on just tow, and I
think there are some three channel ABS systems, probably two in front and one
for both rears.
You should have felt the ABS pulsing the brakes. If not, there was something
wrong with the pump and you should have seen a warning light.
The speed sensors are similar to the ones we use for rally computers. Some
rallyists even connect the ABS sensors to their computers.
Also, be aware that the ABS pump requires a brake fluid that keeps it
lubricated. Do not use DOT 5 silicone brake fluid with ABS.
Allen Hefner
Philly Region SCCA Rally Steward
'77 Midget
'92 Mitsubishi Expo LRV Sport
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