Legacy Brighton Wagon AWD F4-2.2L SOHC (1997)
3) Pressure-hold conditions.
During ABS control, the fluid pressure is kept constant and pressure-hold conditions are maintained by the valves in front of and behind the
pressure rise/drop control, i.e., the inlet valve is ON (closed) and the outlet valve is OFF (closed). The figure shows hydraulic oil channels under
these conditions (all channels under pressure-hold conditions). Under these conditions the sections between the M/C and W/C and between the
W/C and M/C reservoir are closed by solenoid valves (FRI, FRO--RRI, RRO), and the W/C fluid pressure is kept constant.
4) Pressure-rise conditions.
Once wheel lock can be avoided due to the drop in pressure, the inlet and outlet valves both go OFF in order to increase the W/C fluid pressure
again and secure braking force. Hydraulic oil channels under these conditions are shown in Figure. FRI, FRO-RRI, RRO are all shown under
pressure-rise conditions. These conditions are the same as normal hydraulic oil channel conditions, i.e., the section between the M/C pressure
chamber and W/C is open and the section between the W/C and M/C reservoir is closed. By keeping FRI-RRI open on the M/C pressure chamber
side (brake pedal is depressed, so pressure is produced) and on the W/C side, the M/C pressure is conducted to the W/C. The actual control at this
time increases the pressure in steps, repeatedly increasing and holding the pressure, until the tendency for the wheels to lock re-occurs. At that
time, since the M1C fluid enters the W/C, the brake pedal is stroked in stages. The stroke rate is detected by the stroke sensor, and when it has
reached the predetermined value, the motor pump operates and fluid is pressure-fed from the M/C reservoir to the M/C pressure chamber, and the