Abs Operation; Abs Cycle Phases - APRILIA TUAREG 660 Service Station Manual

Braking system
5. Front brake master cylinder
6. Rear brake pump
7. Front brake control lever
8. Rear brake pedal
9. Front brake circuit inlet solenoid valve (normally open)
10.Rear brake circuit inlet solenoid valve (normally open)
11.Front brake circuit outlet solenoid valve (normally closed)
12.Rear brake circuit outlet solenoid valve (normally closed)
13.Rear/front brake circuit low pressure accumulator
14.Dual hydraulic circuit pump (ABS)
15.Hydraulic circuit motor
16.DC electric motor
Inlets and outlets:
1. Supply to the rear brake calliper.
2. Intake from the rear brake pump.
3. Inlet from front brake master cylinder.
4. Outlet to front brake calliper.

ABS OPERATION

General specifications:
The front circuit is the same as the rear one.
•
The ABS inlet valve (9 - 10) is normally open and it is closed only when the system intervenes
to avoid wheel locking.
•
The exhaust valve (11 - 12) is normally closed and it is opened only when the system in-
tervenes to avoid wheel locking.
•
With the system in stand-by mode, the ABS processor controls the wheel speed instant by
instant to assess any slippage of the wheels.
•
When in standby, the system does not intervene at all when the rider brakes; the braking
system is the same as the one without ABS.
ABS Cycle phases (the following operations refer to the front circuit but they are also valid for
the rear):
A - Brake activation: the rider starts braking as he would usually do.
B - Pressure reduction: coincides with the recognition of the dangerous situation (wheel slippage
exceeds the threshold): the system closes the inlet valve (9-10) and opens the outlet valve (11-12)
temporarily.
BRAK SYS - 226
TUAREG 660