FORD MUSTANG 2003 Workshop Manual

DESCRIPTION AND OPERATION
Brake Booster —
Vacuum
Power Brake Booster
The vacuum type power brake booster (2005):
zis a dual diaphragm, vacuum assisted power brake booster
z reduces brake pedal force and travel distance.
z is located on the LH side of the bulkhead in the engine compartment, between the brake pedal
(2455) and the brake master cylinder (2140).
z is divided into separate chambers by the diaphragms.
z will not operate if vacuum is restricted or if any of the vacuum related power brake components
fail.
z is installed as an assembly.
If the power assist fails, the brake system will continue to operate with increased brake pedal effort.
Hose and Check Valve
The power brake booster check valve (2365): SECTION 206-
07: Power Brake Actuation 2003 Mustang Workshop Manual Item Part Number Description
1 2140 Master cylinder
2 2B560 Hydro-Boost
3 2005 Power brake booster Klj . 1 ba
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z
is located on the front of the power brake booster.
z is installed separately; (install a new grommet when installing a new check valve).
z is positioned between the power brake booster and the power brake booster hose.
z closes when the engine is turned off.
z in the closed position, traps engine vacuum in the power brake booster
z retains vacuum to provide several power assisted brake applications with the engine off. Item Part Number Description
1 2140 Master cylinder
2 2005 Power brake booster Klj . 2 ba
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DESCRIPTION AND OPERATION
Brake Booster —
Hydro-Boost
The Hydro- Boost brake booster is a hydraulically operated brake booster powered by the power
steering pump (3A674). The power steering pump provides the fluid pressure to operate both the
power brake booster and the power steering gear (3504).
A Hydro- Boost reserve system (accumulator) stores sufficient fluid under pressure to provide at least
two power- assisted brake applications in the event the power steering pump fluid flow is interrupted.
For low assist concerns on vehicles equipped with the Hydro- Boost system, refer to Section 211 - 00 to
check the power steering pump pressure and flow.
The brakes can also be applied manually if the reserve system is depleted.
Any leakage goes directly back to the power steering pump reservoir (3E764). SECTION 206-
07: Power Brake Actuation 2003 Mustang Workshop Manual Item Part Number Description
1 2140 Master cylinder
2 2B559 Hydro-Boost Klj . 1 ba
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Klj . 2 ba
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GENERAL PROCEDURES
Hydro-
Boost Bleeding
1. NOTE: The Hydro- Boost power brake booster (2B560) is generally self- bleeding, and the
following procedure will normally bleed the air from the power brake booster. Normal operation
of the vehicle will further remove any additional trapped air.
Fill the power steering oil reservoir (3A697) with MERCON® Multi- Purpose ATF XT-2-QDX or
MERCON® equivalent.
2. Remove the powertrain control module (PCM) fuse to prevent the engine from starting.
3. Crank the engine for several seconds.
4. Check the fluid level in the power steering oil reservoir and add if necessary. Install the powertrain control module (PCM) fuse.
5. Start the engine.
6. With the engine running, turn the steering wheel (3600) from stop- to-stop twice. Turn the engine
off.
7. Depress the brake pedal (2455) several times to discharge the accumulator.
8. Repeat Steps 5 and 6.
9. If foaming occurs, stop the engine and allow the foam to dissipate.
10. Repeat Steps 5 and 6 as required, until all the air is removed from the system (when the foaming stops).
SECTION 206-
07: Power Brake Actuation 2003 Mustang Workshop Manual Klj . 1 ba
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Klj . 2 ba
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REMOVAL AND INSTALLATION
Brake Booster —
Vacuum
Removal 1. Disconnect the battery ground cable (14301). For additional information, refer to Section 414 -
01 .
2. Remove the air cleaner housing. For additional information, refer to Section 303 - 12 .
3. Remove the brake master cylinder nuts.
4. Position the brake master cylinder (2140) aside.
5. With the engine off, depress the brake pedal (2455) several times to discharge the accumulator. Disconnect the booster vacuum hose.
6. Remove the stoplight switch self- locking pin.
SECTION 206-
07: Power Brake Actuation 2003 Mustang Workshop Manual Klj . 1 ba
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7. Remove the stoplight switch (13480) and the brake booster push rod from the brake pedal pin.
8. Remove the power brake booster nuts.
9. Remove the power brake booster (2005).
Installation 1. Follow the removal procedure in reverse order. Klj . 2 ba
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Klj . 3 ba
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REMOVAL AND INSTALLATION
Brake Booster —
Hydro-Boost
Removal WARNING: The power brake booster should not be carried by the accumulator, nor
should it ever be dropped on the accumulator. Check the snap ring on the accumulator for
correct seating before the power brake booster is used. The accumulator contains high-
pressure nitrogen gas and can be dangerous if mishandled.
WARNING: If the accumulator is to be disposed of, it must not be exposed to excessive
heat. Before discarding the accumulator, drill a 1.6- mm (1/16-inch) diameter hole in the end of
the accumulator can to relieve the gas pressure. Always wear safety glasses when performing
this operation.
1. With the engine off, depress the brake pedal (2455) several times to discharge the accumulator.
2. Disconnect the battery ground cable (14301). For additional information, refer to Section 414 -
01 .
3. Disconnect the fluid level sensor connector.
4. Disconnect the brake tubes.
SECTION 206-
07: Power Brake Actuation 2003 Mustang Workshop Manual Special Tool(s)
Installer Set, Teflon Seal
211-
D027 (D90P-3517- A) or
equivalent Klj . 1 ba
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