Wheel Speed Sensor/Pulser Ring; 3-Stage Cut-Off Valve - Honda GL1800 Service Manual

*3-STAGE CUT-OFF VALVE

A 3-stage cut-off valve was created by adding a spring-loaded orifice valve on top of a spring-loaded ball-type cut-off valve.
By positioning the orifice valve in-line with the cut-off valve we obtain three stages of operation.
Stage 1:
When the ABS is engaged, the control piston moves down to cut off flow to both the cut-off valve and orifice valve, elimi-
nating hydraulic flow between the master cylinder and brake caliper.
Stage 2:
The control piston moves up slightly to open the cut-off valve, leaving the orifice valve closed. This stage permits only a
small amount of hydraulic pressure to flow through the orifice valve to the brake caliper.
Stage 3:
The control piston returns to its normal, uppermost position, opening both the cut-off valve and orifice valve, and restoring
full hydraulic pressure for conventional brake operation.
CUT- FF VALVE
C NTR L PIST N

WHEEL SPEED SENSOR/PULSER RING

The wheel speed sensor is a contactless sensor that detects front and rear wheel speed. The sensor consists of a perma-
nent magnet and Hall element, and is connected to the ABS control unit. When the projection on the pulser ring (that is
rotating with the wheel) passes across the wheel speed sensor, voltage pulses are generated at the sensor. The ABS con-
trol unit detects the wheel speed as it receives the pulse signal, because the frequency of the signal increases proportion-
ally to the wheel speed.
Rear wheel sensor shown:
PULSER RING
WHEEL SPEED SENSOR
RIFICE VALVE
Closed
Closed
Stage 1
PULSE SIGN LS
TECHNICAL FEATURES
Closed
pen
Stage 2 Stage 3
t low speed
t high speed
pen
pen
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