Town Car V8-4.6L VIN W (1997)
Hydraulic Control Assembly - Antilock Brakes: Description and Operation
DESCRIPTION
The ABS hydraulic control unit:
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Is located in the front of the engine compartment on the LH side below the engine air cleaner.
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Consists of a brake pressure control valve block, pump motor and ABS control module.
The ABS-only ABS control module, brake pressure control valve block and pump motor are physically different than the ABS with traction
control ABS control module, brake pressure control valve block and pump motor.
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The ABS-only brake pressure control valve block is 102 mm (4 inches)long and has only three outlet tube ports. The ABS-only pump motor is
approximately 76 mm (3 inches) tall and both inlet tube ports are at the same level. The inlet port is 4.76 mm (3/16 inch).
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The ABS with traction control brake pressure control valve block is 152 mm (6 inches) long and has four outlet tube ports. The ABS with
traction control pump motor is approximately 102 mm (4 inches) tall and has one tube inlet port 25 mm (1 inch) above the other port.
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The ABS with traction control brake pressure control valve block uses a larger 6.35 mm (1/4 inch) diameter tube from the brake master
cylinder to the pump motor assembly.
OPERATION
Operation of the hydraulic control unit is as follows:
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During normal braking, fluid from the brake master cylinder enters through two inlet ports at the top of the pump motor.
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The fluid then passes through four normally open inlet valves so the rear brakes can be operated independently.
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If the ABS control module senses that a wheel is about to lock, the ABS control module closes the appropriate inlet. This prevents any more
