Hi,
I was in this web site the other day (BBA-Reman.com) and you may find this helpful.
Other factors can cause ABS problems. Be sure to check these before purchasing a new system
1. Incorrect Jump Starting. If one incorrectly reverses the connections (even momentarily), a relay or the main controller may get burnt out.
2. Different tyre or wheel sizes will confuse the controller and may give a speed comparison alarm
3. ABS Wheel sensors do fail. Check resistances to specifications.
4. ABS Sensor Lead Faults
5. Sender rotor is cracked or warped
6. Wheel bearing wear that can cause gap between sensor and rotor to vary
How ABS Works
The three parts of any ABS system, whether combined or separate, are very similar to the human body. The brain or the controller monitors external sensors for wheel lock. The modulator acts as the muscles of the system, controlling the braking force on each wheel by venting pressure using solenoids. If the pressure eventually becomes too low under ABS conditions the heart of the system, the pump, starts to drain the vented fluid from expansion chambers in the modulator back in to the system to maintain correct pressure. All the driver experiences is a slight vibration of the pedal, as this cycle happens many times a second.
Cheers now
Ken Chapman
April 2007