Honda Acura NSX 1991 Service Manual page 723

ALB Description
Features/Construction/Operation
If brake inputs (force excerted
unit operates the solenoid valve, closing the outlet valve and opening the inlet valve. As a result, the high pressure is
directed into chamber C, the piston is pushed upward, causing ths slide piston to move upward and the cut-off valve to
close.
As the cut-off valve closes, the flow from the master cylinder to the caliper is interrupted, the volume of chamber B,
which is connected to the caliper, increases, and the fluid pressusre in the caliper declines.
When both of the two valves, inlet and outlet, are closed (when only the outlet valve is activated) the pressure in the
caliper is maintained constant.
When the possibility of wheel locking ceases, it is necessary to restore the pressure in the caliper. The solenoid valve is
therefore turned off (outlet valve: open, inlet valve closed).
Process
Caliper pressure constant
Caliper pressure increasing
Slide Piston Function
When the car is used on rough roads where the tires sometimes lose adhesion, the anti-lock brake system may function
excessively, causing an excessively large volume of brake fluid to flow into the chamber C. As this occurs, the piston is
moved excessively, resulting in an abnormal loss of pressure in the chamber B. In order to overcome this problem, the
slide piston is kept in the proper position by the spring force to avoid a negative pressure in the chamber B.
RESERVOIR
\
ACCUMULATOR
Kickback
When anti-lock brake system is functioning, the piston moves upward, the volume of chamber B increases, and the fluid
pressure on the caliper side is reduced. At the same time, the volume of chamber A is reduced and the brake fluid is
returned to the master cylinder. When the brake fluid is pushed back to the master cylinder, the driver can feel the func-
tioning of the anti-lock brake system because the brake pedal is kicked back.
19-36
on brake pedal) are excessively large and a possibility of wheel locking occurs, the control
Caliper Pressure
H o l d -
P I S T O N
PRESSURE
SWITCH
Outlet Valve
Electric Hydraulic
Power Circuit
Close
O N Close
Open
CHAMBER D
\
CHAMBER C
Inlet Valve
Electric Hydraulic
Power Circuit
ON Open
OFF Close
OFF Close
MASTER
CYLINDER