brake light FORD MUSTANG 2003 User Guide

condition. It may not always be necessary to follow a pinpoint test to its conclusion. Carry out only the
steps necessary to correct the condition. Then, test the system for normal operation. Sometimes, it is
necessary to remove various vehicle components to gain access to the component requiring testing.
Reinstall all components after verifying system operation is normal.
PINPOINT TEST A: BRAKE VIBRATION/SHUDDER
Test Step Result / Action to Take
A1 ROAD TEST THE VEHICLE—
LIGHT BRAKING z
Check that the wheel and tires are correct for the vehicle.
Inspect the tires for abnormal wear patterns.
z Road test the vehicle. Warm the brakes by slowing the vehicle
a few times from 80– 32 km/h (50 to 20 mph) using light braking
applications. At highway speeds of 89–97 km/h (55- 60 mph),
apply the brake using a light pedal force.
z Is there a vibration/shudder felt in the steering wheel, seat
or brake pedal? Yes
GO to
A4 .
No
GO to A2 .
A2 ROAD TEST THE VEHICLE—
MODERATE TO HEAVY
BRAKING z
Road test the vehicle. At highway speeds of 89–97 km/h (55- 60
mph), apply the brake using a moderate to heavy pedal force.
z Is there a vibration/shudder? Yes
For vehicles with ABS,
GO to
A3 . For vehicles
with standard brakes,
GO to A4 .
No
Vehicle is OK. VERIFY
condition with customer.
TEST the vehicle for
normal operation. A3 NORMAL ACTUATION OF THE ABS SYSTEM DIAGNOSIS
z
During moderate to heavy braking, noise from the hydraulic
control unit (HCU) and pulsation in the brake pedal can be
observed. Pedal pulsation coupled with noise during heavy
braking or on loose gravel, bumps, wet or snowy surfaces is
acceptable and indicates correct functioning of the ABS
system. Pedal pulsation or steering wheel nibble, (frequency is
proportioned to the vehicle speed) indicates a concern with a
brake or suspension component.
z Is the vibration/shudder vehicle speed sensitive? Yes
GO to
A5 .
No
The brake system is
operating correctly. A4 APPLICATION OF THE PARKING BRAKE
z
NOTE: Begin at the front of the vehicle unless the vibration or
shudder has been isolated to the rear.
z This test is not applicable to vehicles with drum- in-hat type
parking brakes. For vehicles with drum- in-hat parking brakes,
proceed to the next test. For all other vehicles, apply the
parking brake to identify if the problem is in the front or rear
brake. At highway speeds of 89–97 km/h (55- 60 mph), lightly
apply the parking brake until the vehicle slows down. Release
the parking brake immediately after the test.
z Is there a vibration/shudder? Yes
GO to
A7 .
No
GO to A5 .
A5 CHECK THE FRONT WHEEL BEARINGS
z
Check the front wheel bearings. Refer to Wheel Bearing Check in this section.
z Are the wheel bearings OK? Yes
GO to
A6 . Klj . 48 ba
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6. For vehicles with a two-
piece hub and brake disc assembly:
z Match-mark before disassembly.
z Remove the brake disc.
z Clean the hub and brake disc mounting surfaces with metal surface cleaner.
z Using a die grinder with a mild abrasive (Scotch Brite® type), remove any rust or
corrosion from the hub and brake disc mounting surfaces.
z Align the match- marks and reinstall the brake disc on the hub.
7. CAUTION: Do not use a bench lathe to machine brake discs.
NOTE: The depth of cut must be between 0.10 and 0.20 mm (0.004 and 0.008 inch). Lighter
cuts will cause heat and wear. Heavier cuts will cause poor brake disc surface finish.
Using an on- car brake lathe, machine the brake discs. Follow the manufacturer's instructions.
After machining, make sure the brake disc still meets the thickness specification.
8. Using the special tools, verify that the brake disc lateral runout is now within specification. For additional information, refer to Section 206 - 00 .
9. Remove the special tool hub adapter.
10. Remove any remaining metal chips from the machining operation.
11. For vehicles with a two- piece hub and brake disc assembly:
z Remove the brake disc from the hub.
z Remove any remaining metal chips from hub and brake disc mounting surfaces and from
the ABS sensor.
z Apply a liberal amount of lubricant to the hub flange, pilot area and to the brake disc- to-
hub mounting surface.
z Using the match marks, mount the brake disc on the hub.
12. Install the brake caliper anchor plate and the brake caliper.
13. Install the tire and wheel assembly.
14. Test the system for normal operation. Klj . 2 ba
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Component Tests
Driveline Vibration
An analysis of driveline vibration can also be conducted using the Vibration Analyzer; follow the
manufacturer's directions.
Driveline vibration exhibits a higher frequency and lower amplitude than does high-
speed shake.
Driveline vibration is directly related to the speed of the vehicle and is usually noticed at various speed
ranges. Driveline vibration can be perceived as a tremor in the floorpan or is heard as a rumble, hum,
or boom. Driveline vibration can exist in all drive modes, but may exhibit different symptoms depending
upon whether the vehicle is accelerating, decelerating, floating, or coasting. Check the driveline angles
if the vibration is particularly noticeable during acceleration or deceleration, especially at lower speeds.
Driveline vibration can be duplicated by supporting the axle upon a hoist or upon jack stands, though
the brakes may need to be applied lightly in order to simulate road resistance.
1. Raise the vehicle promptly after road testing. Use a twin- post hoist or jack stands to prevent tire
flat- spotting. Engage the drivetrain and accelerate to the observed road test speed to verify the lubricant type.
205 - 02B . CLEAN and
REFILL the axle to
specification.
z Axle overheating zLubricant level too
low. z
CHECK the lubricant level.
FILL the axle to specification.
z Incorrect or
contaminated
lubricant type. z
INSPECT the axle for
damage. REPAIR as
necessary. CLEAN and
REFILL the axle to
specification.
z Bearing preload
adjusted too tight. z
CHECK the ring and pinion for
damage. INSPECT the ring
and pinion wear pattern.
ADJUST the preload as
necessary.
z Excessive gear
wear. z
INSPECT all the axle gears
for wear or damage. INSTALL
new components as
necessary.
z Incorrect ring gear
backlash. z
INSPECT the ring gear for
scoring. INSPECT the ring
and pinion wear pattern.
ADJUST the ring gear
backlash as necessary.
z Broken gear teeth
on the ring gear
or pinion z
Overloading the
vehicle. z
INSTALL a new ring and
pinion. REFER to Section 205 - 02A or
Section 205 - 02B .
z Axle shaft broken zOverloading the
vehicle. z
INSTALL a new axle shaft.
REFER to Section 205 - 02A or
Section 205 - 02B .
z Misaligned axle
shaft tube. z
INSPECT the axle for
damage. CHECK axle shaft
tube alignment. INSTALL a
new axle shaft. REFER to
Section 205 - 02A or
Section 205 - 02B . Klj . 11 ba
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off the floor.
With the engine off, raise only one rear wheel. Install the special tool on the wheel nuts.
Use a torque wrench with a capacity of at least 271 Nm (200 lb-
ft) to rotate the axle shaft. Be sure that
the transmission is in NEUTRAL, and that one rear wheel is on the floor while the other rear wheel is
raised off the floor. The breakaway torque required to start rotation must be at least 27 Nm (20 lb- ft).
The initial breakaway torque may be higher than the continuous turning torque.
The axle shaft must turn with even pressure throughout the check without slipping or binding. If the
torque reading is less than specified, check the differential case. Refer to Section 205 - 02A or
Section 205 - 02B .
Traction- Lok® Differential Check Road Test
1. Place one wheel on a dry surface and the other wheel on ice, mud or snow.
2. Gradually open the throttle to obtain maximum traction prior to break away. The ability to move the vehicle demonstrates correct operation of a Traction- Lok® rear axle assembly.
3. When starting with one wheel on an excessively slippery surface, a slight application of the parking brake may be necessary to help energize the Traction- Lok® feature of the differential.
Release the brake when traction is established. Use light throttle on starting to provide
maximum traction.
4. If, with unequal traction, both wheels slip, the limited slip rear axle has done all it can possibly do.
5. In extreme cases of differences in traction, the wheel with the least traction may spin after the Traction-Lok® has transferred as much torque as possible to the non- slipping wheel. Klj . 15 ba
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not machine a new brake disc.
7. For vehicles with a two- piece hub and brake disc assembly:
z Match-mark before disassembly.
z Remove the brake disc.
z Using a die grinder with a mild abrasive (Scotch Brite® type), remove any rust or
corrosion from the hub and brake disc mounting surfaces.
z Align the match- marks and reinstall the brake disc on the hub.
8. CAUTION: Do not use a bench lathe to machine brake discs.
NOTE: The depth of cut must be between 0.10 and 0.20 mm (0.004 and 0.008 inch). Lighter
cuts will cause heat and wear. Heavier cuts will cause poor brake disc surface finish.
Using on- vehicle brake lathe, machine the brake discs. Follow the manufacturer's instructions.
After machining, make sure the brake disc still meets the thickness specification.
9. Using a dial indicator, verify that the brake disc lateral runout is now within vehicle specification.
10. Remove any metal chips.
11. Remove the hub adapter.
12. Remove any remaining metal chips from the machining operation.
13. CAUTION: Do not carry out this step on rear drum- in-hat brake discs.
For vehicles with a two- piece hub and a non drum- in-hat brake disc assembly:
z Remove the brake disc from the hub.
z Remove any remaining metal chips from hub and brake disc mounting surfaces and from
the ABS sensor.
z Apply High Temperature Nickel Anti- Seize Lubricant F6AZ-9L494-AA to the mounting
surfaces.
z Using the match- marks, mount the brake disc on the hub.
14. Install the caliper and check brake operation.
Symptom Chart Symptom Chart
Condition
Possible Sources Action
z The Brakes Pull or
Drift z
Tire air pressure.
z Wheel alignment.
z Brake pads.
z Brake components.
z Suspension
component. z
Go To Pinpoint Test A .
z The Red Brake
Warning Indicator Is z
Instrument cluster.
z Circuit. z
Go To Pinpoint Test B . Klj . 4 ba
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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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