AC system FORD MUSTANG 2003 Workshop Manual

PINPOINT TEST G: HYDRO-
BOOST BRAKE SYSTEM OPERATION
SUSPECT connections between the power steering pump reservoir and
between the power steering pump reservoir and the hydro-
boost
power brake booster.
z Are there any obstructions? REMOVE
obstructions or
INSTALL a new
hose.
No
GO to
F2 .
F2 CHECK BOOSTER OPERATION
z
Have an assistant check the fluid in the power steering pump
reservoir while rapidly applying the brake pedal approximately one
inch.
z Does the fluid show any movement or spouting? Yes
System OK.
No
INSTALL a new
hydro-boost
assembly. Test Step Result / Action to Take
G1 CHECK BASIC OPERATION
z
Key in OFF position.
z Press and release brake pedal several times to deplete all
hydraulic pressure from the hydro- boost power brake
booster.
z Press and hold brake pedal with light pressure.
z Key in START position.
z Does the brake pedal fall slightly and hold, and is less
pressure now required to hold brake pedal at the new
position? Yes
Hydro-
boost is OK.
No
GO to G2 .
G2 CHECK FOR HYDRAULIC BRAKE LEAK
z
With engine running, press and release brake pedal several
times.
z Hold brake pedal down with medium pressure, 34- 47 Nm
(25- 35 lb- ft).
z Does brake pedal move toward floor? Yes
GO to
G3 .
No
GO to G4 .
G3 CHECK FOR LEAKS —
BRAKE FLUID LINES z
Check for leaks at brake lines, including brake master
cylinder and brake hose.
z Do components check OK? Yes
COMPLETE master cylinder
By-
Pass Condition Test in
this section.
No
INSTALL new hoses and
lines as necessary. G4 CHECK HYDRO-
BOOST CONNECTIONS z
Clean the hydro- boost power brake booster, power steering
pressure hose, power steering gear pressure hose and
power steering return hose and connection.
z Start engine and run at idle.
z Check hose connections for leakage.
z Do hose connections check OK? Yes
GO to
G5 .
No
REPAIR or INSTALL new
hose and connections as
necessary. G5 CHECK FOR HYDRO-
BOOST LEAK Klj . 12 ba
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Component Tests
Brake Booster
1. Check the hydraulic brake system for leaks or insufficient fluid.
2. With the transmission (7003) in NEUTRAL, stop the engine (6007) and apply the parking brake control (2780). Apply the brake pedal several times to exhaust all vacuum in the system.
3. Apply the brake pedal and hold it in the applied position. Start the engine. If the vacuum system is operating, the brake pedal will tend to move downward under constant foot pressure. If no
motion is felt, the power brake booster system is not functioning. Continue with the following
steps.
4. Remove the vacuum booster hose from the check valve connection. Manifold vacuum must be available at the check valve end of the vacuum booster hose with the engine at idle speed and
the transmission in NEUTRAL. If the manifold vacuum is available to the power brake booster,
connect the vacuum booster hose to the power brake booster check valve and repeat Steps 2
and 3.
5. If no downward movement of the brake pedal is felt, install a new power brake booster.
6. Operate the engine a minimum of 10 seconds at fast idle. Stop the engine, and let the vehicle stand for 10 minutes. Then apply the brake pedal with approximately 89 N (20 lb) of force. The
brake pedal feel should be the same as that noted with the engine operating. If the brake pedal
feels hard (no power assist), install a new power brake booster check valve and retest. If the
brake pedal feels spongy, bleed the hydraulic system to remove air. For additional information,
refer to Bleeding — System in this section. Check Valve z
Engine running at idle speed.
z CAUTION: Do not hold the brake pedal at 444 Nm
(100 lb) force for more than 5 seconds at a time.
z Apply brake pedal with approximately 444 Nm (100 lb)
force and hold.
z Check hydro-boost unit input seal, housing seal,
accumulator seal, piston seal and spool plug seal for
leakage.
z Is hydro- boost unit free of leaks? Yes
GO to
G6 .
No
INSTALL a new hydro- boost
unit. G6 CHECK RESERVE RETENTION
z
Engine running at idle speed.
z CAUTION: Do not hold the brake pedal at 444 Nm
(100 lb) force for more than 5 seconds at a time.
z Charge system to pressure by holding the steering wheel at
stop or by pressing the brake pedal with approximately 444
Nm (100 lb) force.
z Key in OFF position.
z Wait five seconds.
z Press brake pedal and observe if there is any power brake
reserve.
z Is there any power brake reserve? Yes
Hydro-
boost unit is OK.
No
INSTALL a new hydro- boost
unit. Klj . 13 ba
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The function of the power brake booster check valve is to allow manifold vacuum to enter the power
brake booster and prevent the escape of vacuum in case manifold vacuum is lost during sustained full
throttle operation.
To test the function of the power brake booster check valve :
zStart and run the engine for at least 10 seconds.
z Operate the brake pedal to check for power assist.
z Disconnect the vacuum booster hose from the power brake booster check valve. Do not remove
the power brake booster check valve from the power brake booster.
z There should be enough vacuum retained in the brake booster for at least one more power-
assisted brake operation.
Brake Master Cylinder — Normal Conditions
The following conditions are considered normal and are not indications that the brake master cylinder
is in need of service.
Condition 1: During normal operation of the brake master cylinder, the fluid level in the brake master
cylinder reservoir will rise during brake application and fall during release. The net fluid level (i.e., after
brake application and release) will remain unchanged.
Condition 2: A trace of brake fluid will exist on the booster shell below the master cylinder mounting
flange. This results from the normal lubricating action of the master cylinder bore and seal.
Condition 3: Fluid level will decrease with pad wear.
Brake Master Cylinder — Abnormal Conditions
Changes in brake pedal feel or travel are indicators that something could be wrong in the brake
system. GO to Symptom Chart for abnormal condition diagnosis.
Bypass Condition Test 1. Disconnect the brake lines at the brake master cylinder.
2. Plug the outlet ports of the brake master cylinder.
3. Apply the brakes. If brake pedal height cannot be maintained, the brake master cylinder has an internal leak and must be rebuilt or replaced.
Compensator Port Check
The purpose of the compensator ports in the brake master cylinder is to supply any additional brake
fluid required by the system due to brake pad wear and to allow brake fluid returning from the brake
lines to the brake master cylinder to enter the brake master cylinder reservoir.
The returning brake fluid will cause a slight turbulence in the brake master cylinder reservoir. Klj . 14 ba
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GENERAL PROCEDURES
Bleeding —
Components
Master Cylinder Priming — In-Vehicle or Bench
WARNING: Brake fluid contains polyglycol ethers and polyglycols. Avoid contact with
eyes. Wash hands thoroughly after handling. If brake fluid contacts eyes, flush eyes with
running water for 15 minutes. Get medical attention if irritation persists. If taken internally,
drink water and induce vomiting. Get medical attention immediately.
CAUTION: Do not allow the brake master cylinder reservoir to run dry during the bleeding
operation. Keep the brake master cylinder reservoir filled with the specified brake fluid. Never
reuse the brake fluid that has been drained from the hydraulic system.
CAUTION: Brake fluid is harmful to painted and plastic surfaces. If brake fluid is spilled
onto a painted or plastic surface, immediately wash it with water.
NOTE: When any part of the hydraulic system has been disconnected for repair or installation of new
components, air can enter the system and cause spongy brake pedal (2455) action. This requires
bleeding of the hydraulic system after it has been correctly connected. The hydraulic system can be
bled manually or with pressure bleeding equipment.
NOTE: When a new brake master cylinder (2140) has been installed or the system has been emptied,
or partially emptied, it should be primed to prevent air from entering the system.
1. For in- vehicle priming, disconnect the brake lines.
SECTION 206-
00: Brake System — General Information 2003 Mustang Workshop Manual Special Tool(s)
Worldwide Diagnostic System
(WDS)
418-
F224,
New Generation STAR (NGS)
Tester
418- F052, or equivalent scan
tool NGS Flash Cable
418-
F120 (007- 00531) or
Equivalent Klj . 1 ba
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Four Wheel Anti-
Lock Brake System (4WABS) Hydraulic Control Unit (HCU)
NOTE: This procedure only needs to be performed if the 4- wheel anti-lock brake (4WABS) hydraulic
control unit (HCU) has been installed new or if the HCU lines have been opened.
1. Clean all dirt from and remove the brake master cylinder filler cap (2162), and fill the brake master cylinder reservoir (2K478) with the specified brake fluid.
2. Connect a clear waste line to the RH rear bleeder screw (2208) and the other end in a container partially filled with recommended brake fluid.
3. Loosen the RH rear bleeder screw until a stream of brake fluid comes out. While the assistant maintains pressure on the brake pedal (2455), tighten the RH rear bleeder screw.
zRepeat until clear, bubble- free fluid comes out.
z Refill the brake master cylinder reservoir as necessary.
4. Tighten the RH rear bleeder screw, and disconnect the waste line. Klj . 4 ba
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5. Repeat Steps 2, 3 and 4 for the LH rear bleeder screw, the RH front disc brake caliper (2B120)
bleeder screw, and the LH front disc brake caliper bleeder screw, in that order.
6. Connect the scan tool DCL cable adapter into the vehicle data link connector (DLC) under the dash, and follow the scan tool instructions.
7. Repeat the system bleed procedure as outlined in Steps 1 through 5.
Caliper 1. NOTE: It is not necessary to do a complete brake system bleed if only the disc brake caliper
(2B120) was disconnected.
Place a box end wrench on the disc brake caliper bleeder screw (2208). Attach a rubber drain
tube to the disc brake caliper bleeder screw, and submerge the free end of the tube in a container partially filled with clean brake fluid. Klj . 5 ba
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GENERAL PROCEDURES
Bleeding —
System
Manual
WARNING: Brake fluid contains polyglycol ethers and polyglycols. Avoid contact with
eyes. Wash hands thoroughly after handling. If brake fluid contacts eyes, flush eyes with
running water for 15 minutes. Get medical attention if irritation persists. If taken internally,
drink water and induce vomiting. Get medical attention immediately.
CAUTION: Do not allow the brake master cylinder reservoir to run dry during the bleeding
operation. Keep the brake master cylinder reservoir filled with the specified brake fluid. Never
reuse the brake fluid that has been drained from the hydraulic system.
CAUTION: Brake fluid is harmful to painted and plastic surfaces. If brake fluid is spilled
onto a painted or plastic surface, immediately wash it with water.
NOTE: When any part of the hydraulic system has been disconnected for repair or installation of new
components, air can get into the system and cause spongy brake pedal action. This requires bleeding
of the hydraulic system after it has been correctly connected. The hydraulic system can be bled
manually or with pressure bleeding equipment.
1. Clean all dirt from and remove the brake master cylinder filler cap and fill the brake master cylinder reservoir with the specified brake fluid.
2. Place a box end wrench on the RH rear bleeder screw. Attach a rubber drain tube to the RH rear bleeder screw and submerge the free end of the tube in a container partially filled with
clean brake fluid.
SECTION 206-
00: Brake System — General Information 2003 Mustang Workshop Manual Klj . 1 ba
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5. Loosen the RH rear bleeder screw. Leave open until clear, bubble-
free brake fluid flows, then
tighten the RH rear bleeder screw and remove the rubber hose.
6. Continue bleeding the rear of the system, going in order from the LH rear bleeder screw to the RH front disc brake caliper bleeder screw ending with the LH front disc brake caliper bleeder
screw.
7. Close the bleeder tank valve. Remove the tank hose from the adapter, and remove the adapter. Klj . 4 ba
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GENERAL PROCEDURES
Hydraulic Leak Check
1. NOTE: Brake fluid is water soluble and it is possible that all evidence of fluid leakage has been
washed off if the vehicle has been operated in the rain or snow.
Make sure the brake master cylinder reservoir (2K478) is full.
2. Apply the brakes several times and make sure the brake pedal (2455) feel is not spongy. If necessary, bleed the system. For additional information, refer to Bleeding — System in this
section.
3. If the reservoir level is dropping, inspect the brake components, fittings and lines to locate the source of the leak.
SECTION 206-
00: Brake System — General Information 2003 Mustang Workshop Manual Klj . 1 ba
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GENERAL PROCEDURES
Runout Check —
Brake Disc and Hub
CAUTION: The brake disc (1126) runout specification must be met to ensure correct brake
performance without roughness complaints.
CAUTION: Do not install brake discs that are less than the minimum thickness specified.
Do not machine a brake disc below the minimum thickness specification.
NOTE: When installing brake discs, always align the painted match marks on the brake discs with
those on the front hub or rear axle.
NOTE: When installing brake discs, always apply anti- seize lubricant to the brake disc-to-front hub or
to the brake disc- to-rear axle mating surfaces.
1. Do not remove the tire and wheel assembly. Tighten the wheel nuts to specification with a torque stick or torque wrench.
2. Raise and support the vehicle.
3. Assemble the Brake Measurement Kit, using the spherical tip extension.
4. Locate an opening on the inboard side of the dust shield that will allow the dial indicator tip to be positioned at least 5 mm (0.2 inch) from the outer edge of the brake disc.
5. NOTE: Do not clamp the gauge set to a vehicle component separated from the brake disc by a
flexible joint, such as a ball joint or body mount.
Clamp the Brake Measurement Kit on the vehicle, making sure the flexible indicator arm and
probe tip do not touch the dust shield or tire while rotating.
6. NOTE: For rear wheel measurement only, have an assistant push in on the wheel cover or axle
shaft center while rotating the wheel.
Rotate the wheel for six revolutions, and record the total indicated runout.
SECTION 206-
00: Brake System — General Information 2003 Mustang Workshop Manual Special Tool(s)
Brake Measurement Kit
134-R0199 or equivalent
Material Item Specification
High Temperature Nickel Anti-
Seize Lubricant
F6AZ-
9L494- AA ESE-
M12A4-
A Klj . 1 ba
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