Passport 2WD V6-3.2L SOHC (6VD1) (1995)
Hydraulic Control Assembly - Antilock Brakes: Description and Operation
ANTI-LOCK HYDRAULIC VALVE ASSEMBLY
The anti-lock hydraulic valve assembly contains:
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Isolation valve (normally open)
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Dump valve (normally closed)
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Accumulator
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Reset switch
The anti-lock hydraulic valve assembly is installed in the brake hydraulic system between the proportioning valve and the rear brakes. The two
hydraulic valves are operated by solenoids; the EBCM controls rear brake pressure by controlling current flow through these solenoids.
During normal braking hydraulic fluid flows from the master cylinder and proportioning valve through the anti-lock valve assembly to the rear brakes.
When the brake pedal switch closes (brake pedal applied), the EBCM checks the speed sensor signal. If the EBCM detects that rear wheel speed is
dropping too quickly, indicating possible rear wheel lock-up, the EBCM energizes the isolation solenoid to close the isolation valve. This separates
the rear wheel cylinders from the master cylinder so that rear brake pressure cannot increase.