2003 FORD MUSTANG light

Always On
zParking brake.
z Brake fluid level.
z Vibration When
Brakes Are Applied z
Rear disc brakes.
z Front disc brakes. z
REFER to Section 100 -
04 .
z Brake Pedal Goes
Down Fast z
Brake fluid level. zFILL the brake master
cylinder reservoir.
BLEED the system.
z Air in system. zBLEED the system.
z Brake master
cylinder. z
PERFORM the brake
master cylinder
component test in this
section.
z The Brake Pedal
Eases Down Slowly z
Air in system. zBLEED the system.
REFER to Bleeding —
System in this section.
z Brake master
cylinder. z
PERFORM the brake
master cylinder
component test in this
section.
z Brake Lockup During
Light Brake Pedal
Force z
Disc brake
component.
z Parking brake
component.
z Anti- lock brake
control system. z
Go To Pinpoint Test C .
z Excessive/Erratic
Brake Pedal Travel z
Leak in hydraulic
system.
z Air in system.
z Disc brake caliper.
z Brake master
cylinder. z
Go To Pinpoint Test D .
z Brakes Drag zParking brake
component. z
REPAIR or INSTALL new
components as
necessary. REFER to
Section 206 - 05 .
z Disc brake caliper. zREPAIR or INSTALL a
new brake caliper as
necessary. REFER to
Section 206 - 03 and
Section 206 - 04 .
z Brake booster-to-
brake master
cylinder push rod
adjustment. z
ADJUST the push rod.
REFER to Section 206 -
07 .
z Brake master
cylinder. z
PERFORM the brake
master cylinder
component test in this
section.
z Excessive Brake
Pedal Effort z
Power brake
booster. z
PERFORM the brake
booster component test
in this section.
z Power brake
booster check
valve (2365). z
PERFORM the check
valve component test in
this section.
z Power brake
booster hose. z
REROUTE, REPAIR or
INSTALL a new brake Klj . 5 ba
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z
Key in ON position.
z Does the brake warning indicator stay on? cylinder reservoir. TEST the
system for normal operation.
B2 CHECK PARKING BRAKE SWITCH
z
Key in OFF position.
z Disconnect: Parking Brake Switch.
z Key in ON position.
z Does the brake warning light stay on? Yes
GO to
B3 .
No
INSTALL a new parking brake
switch. TEST the system for
normal operation. B3 CHECK THE GEM
z
Key in OFF position.
z Disconnect: GEM C201e.
z Measure resistance to ground at C201e- 13.
z Is the resistance greater than 10,000 ohms? Yes
REPAIR the GEM. TEST the
system for normal operation.
No
For vehicles without Daytime
Running Lights (DRL), GO to
B4
. For vehicles with DRL, GO
to B5 .
B4 CHECK CIRCUITS 977 (VT/WH), 22 (LB/BK) AND 128
(VT/YE) z
Remove the fused jumper from C124.
z Measure the resistance to ground at C124- 2.
z Is the resistance greater than 10,000 ohms? Yes
REPAIR the ground short in
circuit 128 (VT/YE). TEST the
system for normal operation.
No
REPAIR the ground short in
circuit 977 (VT/WH) or circuit 22
(LB/BK). TEST the system for
normal operation.
B5 CHECK CIRCUIT 128 (VT/YE)
z
Remove the fused jumper from C124.
z Measure the resistance to ground at C201e- 13. Yes
GO to
B6 . Klj . 8 ba
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PINPOINT TEST C: BRAKE LOCKUP DURING LIGHT BRAKE PEDAL
FORCE z
Is the resistance greater than 10,000 ohms? No
REPAIR the ground short in
circuit 128 (VT/YE). TEST the
system for normal operation.
B6 CHECK DAYTIME RUNNING LIGHTS (DRL) MODULE
z
Disconnect: DRL Module C1030.
z Measure the resistance to ground at C124- 2.
z Is the resistance greater than 10,000 ohms? Yes
REPAIR the DRL module. TEST
the system for normal operation.
No
REPAIR the ground short in
circuit 22 (LB/BK) or 977
(VT/WH). TEST the system for
normal operation.
Test Step Result / Action to Take
C1 INSPECT THE TIRES
z
Inspect the tires for uneven or excessive
wear, correct pressure, correct size and
type.
z Are the tires OK? Yes
GO to
C2 .
No
CORRECT as necessary. RETEST for
normal operation. C2 CHECK THE BRAKE CALIPER
COMPONENTS z
Inspect the brake pads and brake discs for
wear, damage, contamination and correct
installation.
z Are the brake components OK? Yes
GO to
C3 .
No
CORRECT as necessary. RETEST for
normal operation. C3 CHECK THE PROPORTIONING VALVE
z
Install the gauges from the ABS brake and
pressure test kit on one front and one rear
bleeder screw.
z Apply 6895 kPa (1000 psi) to the front
brake system.
z Is the pressure in the rear system 3516- Yes
INSPECT the disc brake calipers and
INSTALL new calipers as necessary.
RETEST for normal operation.
No Klj . 9 ba
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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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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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NOTE:
Use new brake fluid when assembling and bleeding the brake system.
NOTE: Lightly lubricate the parking brake lever bore, limiting bolt, parking brake lever shaft and
parking brake shaft recess with Silicone Dielectric Compound D7AZ-19A331- A or equivalent
meeting Ford specification ESE- M1C171-A.
Follow the disassembly procedure in reverse order. Klj . 4 ba
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REMOVAL AND INSTALLATION
Pedal and Bracket
Removal
1. Disconnect the battery ground cable (14301). For additional information, refer to Section 414 -
01 .
2. Remove the stoplight switch retaining pin.
3. Slide the stoplight switch (13480) and booster push rod from the brake pedal pin.
4. Remove the brake pedal bracket retaining bolt.
5. Remove the brake pedal bracket retaining nuts.
SECTION 206-
06: Hydraulic Brake Actuation 2003 Mustang Workshop Manual Klj . 1 ba
32003 Mustang Workshop Manual
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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
32003 Mustang Workshop Manual
17. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_4464/S3B~us~en~ ...