206-00-3 Brake System - General Information 206-00-3
DIAGNOSIS AND TESTING
Brake System
The brakes system operates by transferring effort
applied to the brake pedal by the driver to the
brakes at each wheel.
The braking effort is distributed to each wheel,
using a hydraulic system. The system is assisted
using a vacuum brake booster that reduces pedal
effort and increases hydraulic pressure.
The parking brake operates on the rear wheels
and is applied using a hand operated control.
lnspection and Verification
N0TE:Before carrying out any diagnosis, make
sure that the brake system warning indicator is
functional.
1. Verify the customer concern.
2. Visually inspect for obvious signs of mechanical
damage.
3. If an obvious cause for an observed or reported
concern is found, correct the case (if possible)
before proceeding to the next step.
4. If the cause if not visually evident, verify the
symptom and refer to the Symptom Chart.
Visual lnspection Chart
Road Test
1.
Perform a road test to compare actual vehicle
braking performance with the performance
standards expected by the driver. The ability of the
test driver to make valid comparisons and detect
performance deficiencies will depend on
experience.
Mechanical
- Tire pressure
- Wheels and tires
- Fluid leak from brake line(s)
The driver should have a thorough knowledge of
the brake system operation and accepted general
performance guidelines to make good comparisons
, and detect performance concerns.
An experienced technician will always establish a
route that will be used for all brake diagnosis road
tests. The road selected will be reasonably smooth and level. Gravel
or bumpy roads are not suitable
because the surface does not allow the tires to grip
the road equally. Crowned roads should be avoided
because of the large amount of weight shifted to
the low set of wheels on this type of road. Once
the route is established and consistently used, the
road surface variable can be eliminated from the
test results.
Before a road test, get a complete description of
the customer concerns or suspected condition.
From the description, the technician will be able to
match possible causes with symptoms. Certain
components will be identified as possible sources
while others will be eliminated by the evidence.
More importantly, the customer description can
reveal unsafe conditions which should be checked
or corrected before a road test. The description will
also help form the basic approach to the road test
by narrowing the concern to specific components,
vehicle speed or conditions.
Begin the road test with a general brake
performance check. Using the description of the
concern, test the brakes at different vehicle speeds
using both light and heavy pedal pressure.
Determine if the concern is in the front or rear
braking system. First use the foot brake and then
the parking brake. If the condition
(i.e. pull,
vibration, pulsation) occurs only on operation of
the parking brake, the concern is in the rear brake
system.
If the condition occurs when the foot brake
is depressed, the concern is in the front brake
system.
Avoid locking the brakes and sliding the tires. This
condition will not indicate brake efficiency. A heavily
braked but turning wheel will stop the vehicle in a
shorter distance than locked wheels.
If the concern becomes evident during this check,
make sure it fits the description given before the
road test. If the concern is not evident, attempt to
duplicate the condition using the information from
the description.
If a concern exists, use the Brake System Symptom
Chart in order to isolate it to a specific sub-system
and condition description. From this description, a
list of possible sources can be used to further
narrow the cause to a specific component or
condition.
- -
2006.0 Fiesta 1212006 G28494en
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206-004 Brake System - General Information 206-00-4
DIAGNOSIS AND TESTING
Symptom Chart - -
Symptom
Brakes pull or drift
Possible Sources Action
Worn or damaged brake shoes
or brake pads and linings. INSTALL
new brake shoes or ,
brake pads. REFER to:
Brake Shoes (206-02 Drum
Brake, Removal and Installa-
tion),
Brake Pads (206-03 Front Disc
Brake, Removal and Installa-
tion),
Brake Pads (206-04 Rear Disc Brake, Removal and Installa-
tion).
Abnormal wear or distortion of
brake discs.
INSTALL a new brake discs.
REFER to: Brake Disc (206-04
Rear Disc Brake, Removal
and Installation).
lncorrect rear brake adjust-
ment. PERFORM
a parking brake
cable adjustment. REFER to:
(206-05 Parking Brake and
Actuation)
Parking Brake Cable Adjust-
ment
- Vehicles With: Rear
Drum Brakes (General
Procedures),
Parking Brake Cable Adjust-
ment
- Vehicles With: Rear
Disc Brakes (General
Procedures).
lncorrect wheel alignment
adjustment. PERFORM a
wheel alignment
adjustment.
REFER to: Front Toe Adjust-
ment (204-00 Suspension
System
- General Informa-
tion, General Procedures).
l ncorrect wheel bearing preload
adjustment. ADJUST or INSTALL a new
wheel bearing. REFER to:
Front Wheel Bearing (204-01 Front Suspension, Removal
and Installation),
Rear Wheel Bearing (204-02 Rear Suspension, Removal
and Installation).
2006.0 Fiesta 1212006 G28494en
Unequal air pressure in the
tires. INFLATE the tires to the correct
pressure.
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206-00-7 Brake System - General Information 206-00-7
DIAGNOSIS AND TESTING
1 Pedal goes down fast
Possible Sources Action
Leak in the hydraulic system. REPAIR the leak. CHECK the
entire hydraulic system. FILL
and BLEED the brake system.
REFER to: (206-00 Brake
System
- General Information)
Brake System Bleeding
(General Procedures),
Brake System Pressure
Bleeding (General Proced-
ures).
Air in the system.
CHECK for leaks. BLEED the
brake system. REFER to: (206-
00 Brake System
- General
Information)
Brake System Bleeding
(General Procedures),
Brake System Pressure
Bleeding (General Proced-
u res).
Worn brake master cylinder piston cups or scored cylinder
bore. INSTALL
a new brake master
cylinder. REFER to: (206-06
Hydraulic Brake Actuation)
Brake Master Cylinder
- RHD
(Removal and lnstallation),
Brake Master Cylinder
- LHD
(Removal and lnstallation).
I Brake disc brake 'knock back' I Install a new brake disc. I
I loose wheel bearings.) I I
(Brake pads push the brake
caliper piston back into brake
caliper. Caused by excessive
brake disc lateral
runout or
Worn brake shoes or brake
pads. REFER to:
Brake Disc (206-04
Rear Disc Brake, Removal
and Installation). INSTALL new brake shoes or
brake pads. REFER to:
Brake Shoes (206-02 Drum
Brake, Removal and Installa-
tion),
Brake Pads (206-03 Front Disc
Brake, Removal and Installa-
tion),
Brake Pads (206-04 Rear Disc Brake, Removal and Installa-
tion).
GO to Pinpoint Test D.
2006.0 Fiesta 1212006 G28494en
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206-00-8 Brake System - General Information 206-00-8
DIAGNOSIS AND TESTING
Svm~tom Possible Sources Action
Pedal eases down slowly Air in the system.
Malfunctioning brake master
cylinder.
BLEED the brake system.
REFER to: (206-00 Brake
System
- General Information)
Brake System Bleeding (General Procedures),
Brake System Pressure Bleeding (General Proced-
ures).
GO to Pinpoint Test E.
Brake, Removal and Installa-
tion),
Brake Pads (206-03 Front Disc
Brake, Removal and Installa-
tion),
Brake Pads (206-04 Rear Disc
Brake, Removal and Installa-
Pedal is low or feels spongy
I tion). I
Brake lockup during light brake I
Worn brake shoes or brake
pads.
pedal force INSTALL new brake shoes or
brake pads. REFER to:
Hydraulic system.
Incorrect tire pressures.
Tires worn.
Glazed or worn brake shoes or
brake pads.
Brake booster.
GO to Pinpoint Test F. I
INFLATE the tires to the correct
pressure.
INSTALL new tires. I
brake pads. REFER to:
Brake Shoes (206-02 Drum
Brake, Removal and Installa-
tion),
Brake Pads (206-03 Front Disc Brake, Removal and Installa-
tion),
Brake Pads (206-04 Rear Disc
Brake, Removal and Installa-
tion).
GO to Pinpoint Test G.
Excessive or erratic pedal
travel Worn brake shoes or brake
pads. INSTALL new brake shoes or
brake pads. REFER to:
Brake Shoes (206-02 Drum Brake, Removal and Installa-
tion),
Brake Pads (206-03 Front Disc Brake, Removal and Installa-
tion),
I
Brake Pads (206-04 Rear Disc
Brake, Removal and Installa-
tion).
2006.0 Fiesta 1212006 G28494en
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206-00-1 0 Brake System - General Information 206-00-1 0
DIAGNOSIS AND TESTING
Pinpoint Tests
PINPOINT TEST A : BRAKES PULL OR DRIFT
TEST CONDITIONS
DETAILSIRESU LTSIACTIONS
A1 : ROAD TEST THE VEHICLE
Road test the vehicle and apply the brake pedal.
Does the vehicle pull or drift?
+ Yes
GO to A2.
+ No
Vehicle OK.
A2: TIRE INSPECTION
Check for excessive wear or incorrect tire pres-
sures.
Are the tires in good condition?
-, Yes
GO to A3.
+ No
INFLATE the tires to the correct pressure.
INSTALL new tires if excessively worn. TEST
the system for normal operation.
A3: BRAKE SHOE OR BRAKE PADS AND LINING INSPECTION
Inspect the brake shoes or brake pads for
grease or fluid on the linings and or wear
concerns.
Are any concerns present?
+ Yes
INSTALL new brake shoes or brake pads.
REFER to:
Brake Shoes (206-02 Drum Brake, Removal and
Installation),
Brake Pads (206-03 Front Disc Brake, Removal
and Installation),
Brake Pads (206-04 Rear Disc Brake, Removal
and Installation).
TEST the system for normal operation.
+ No
GO to A4.
2006.0 Fiesta 1212006 G28494en
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206-00-21 Brake System - General Information 206-00-21
DIAGNOSIS AND TESTING
TEST CONDITIONS DETAILSIRESU LTSIACTIONS
162: TIRE INSPECTION
rn Check for excessive tire wear or incorrect tire
pressures.
Are the tires in good order?
-+ Yes
GO to G3. GO to Pinpoint Test G.
-+ No
SUBSTITUTE known good tires. INFLATE to
the correct pressure. TEST the system for
normal operation.
163: BRAKE SHOES OR BRAKE PADS INSPECTION I
rn Inspect the brake shoes or brake pads are
correctly fitted and for grease or fluid contamin-
ation or wear concerns.
Are there any concerns?
-+ Yes
REPAIR or INSTALL new components as
necessary. TEST the system for normal
operation.
-+ No
GO to G4. GO to Pinpoint Test G.
1 64: CHECK PRESSURE CONSCIOUS REDUCING VALVE-RIGHT-HAND REAR I
rn Install pressure gauges in the left-hand front
and right-hand rear bleed nipples. Apply the brake to read 6895
kPa (1 000 psi) at the left-
hand front wheel.
- Read the pressure at the right-hand rear
wheel.
Does the pressure gauge read between 4692-
5164
kPa (680-750 psi) at the right-hand rear
wheel?
-+ Yes
TEST the brake booster. Go to Pinpoint Test
I.
-+ No
INSTALL a new right-hand rear brake pres-
sure control valve. BLEED the brake system.
REFER to: (206-00 Brake System
- General
Information)
Brake System Bleeding (General Procedures),
Brake System Pressure Bleeding (General
Procedures). TEST the system normal operation.
2006.0 Fiesta 12/2006 G28494en
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Brake System - General Information
DIAGNOSIS AND TESTING
evidence of a brake concern. Check for the brake
warning indicator illumination and the fluid level in
the master cylinder reservoir.
Normal Conditions
The following conditions are considered normal
and are not indications that the brake master
cylinder is in need of service.
- Modern brake systems are not designed to
produce as hard a pedal effort as in the past.
Complaints of light pedal efforts should be
compared to pedal efforts of another vehicle, of
the same model and year.
- During normal operation of the brake the fluid
level in the reservoir will rise during brake
application and fall during release. The net fluid
level
(i.e., after brake application and release)
will remain unchanged.
- A trace of brake fluid will exists on the brake
booster shell below the master cylinder
mounting flange. This results from the normal
lubricating action of the master cylinder bore
end seal.
- The fluid level will fall with brake shoe and lining
wear.
Abnormal Conditions
N0TE:Prior to performing any diagnosis, make
sure the brake system warning indicator is
functional.
Changes in brake pedal feel or travel are indicators
that something could be wrong with the braking system. The diagnostic procedure and techniques
use brake pedal feel, warning indicator illumination
and low brake fluid level as indicators in diagnosing
braking system concerns. The following conditions
are considered abnormal and indicate that the
brake master cylinder is in need of service.
- The brake pedal effort is excessive. This may
be caused by a bind or obstruction in the pedal
.
or linkage, clogged fluid control valve or ( ' insufficient booster vacuum.
- The rear brakes lock up during light pedal force.
This may be caused by incorrect tire pressures,
grease or fluid on the brake shoes and linings,
damaged brake shoes and linings, incorrectly
adjusted parking brake, or damaged or
contaminated brake pressure control valves.
- The brake pedal effort is erratic. This condition
could be caused by a brake booster malfunction,
extreme caliper piston knock back or incorrectly
installed brake shoes and linings.
- The brake warning indicator is ON. This may
be caused by low fluid level, ignition wire routing
too close to the fluid level indicator assembly,
or float assembly damage.
Bypass Condition Test
1. Check the fluid in brake master cylinder. Fill the
brake master cylinder reservoir if low or empty.
2. Observe the fluid level in the brake master
cylinder reservoir. If after several brake
applications, the fluid level remains the same,
measure the wheel turning torque required to
rotate the wheels with the brakes applied as
follows:
Place the transaxle in NEUTRAL and raise and
support the vehicle. REFER to: (1 00-02 Jacking
and Lifting)
Jacking (Description and Operation),
Lifting (Description and Operation).
Apply the brakes with a minimum of 445 N (100
Ib) and hold for approximately 15 seconds. With
the brakes still applied, exert a torque on the front
wheels of 10.1 Nm (75
1b.R). If either wheel rotates,
install a new brake master cylinder. REFER to:
(206-06 Hydraulic Brake Actuation)
- The brake pedal goes down fast. This could be Brake Master Cylinder - RHD (Removal and
caused by an external or internal leak. Installation),
- The brake
pedal eases down slowly. This could Brake Master Cylinder - LHD
(Removal and
be caused by an external or internal leak. Installation).
- The
brake pedal is low and or feels spongy. This
condition may be caused by no fluid in the brake
Non-Pressure Leaks master cylinder reservoir, reservoir cap vent
holes clogged or air in the hydraulic system.
Any empty brake master cylinder reservoir
condition may be caused by two types of
non-pressure external leaks.
2006.0 Fiesta 1212006
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211 -00-5 Steering System - General Information 211 -00-5
DIAGNOSIS AND TESTING
Steering System
/ Special Tool(s)
Alignment Pins, Subframe
205-524
Simulator, Driver and
passenger ~ir Bags and Side
Air Curtains 50
1 -073A
General Eaui~ment
I Worldwide Diagnostic System (WDS) I
Principles of Operation
The steering wheel rotational movement is
transferred to the steering gear through the steering
column shaft. The steering gear converts this
rotational movement, through the action of the rack
and pinion gear into lateral movement. This
movement in turn is transferred to the wheel
knuckles through the tie-rods and tie-rod ends.
Hydraulic fluid under pressure is supplied to the
steering gear by the power steering pump. As the
steering wheel is rotated, the hydraulic fluid is
allowed to pass through the steering gear valve to
one side of a double acting piston, dependent on
which direction the steering wheel is rotated. The
fluid moves the piston, which forms part of the
steering gear, giving power assistance to the effort
required to rotate the steering wheel.
Vehicles with petrol engines, due to the extra load
on the engine imposed by the power steering
pump, have a power steering pressure (PSP)
switch. The switch, which is normally closed, sends a signal
to the powertrain control module (PCM)
during low speed parking manoeuvres. The PCM
responds by maintaining the engine idle speed.
lnspection and Verification
1. Verify the customer concern.
2. Visually inspect for obvious signs of mechanical
or electrical damage.
Visual lnspection Chart
I Mechanical I Electrical I
Tire pressure(s)
Accessory drive belt
Tie-rod ends
Tie-rod (s)
Steering gear housing
Front strut and
spring assemblies
Front suspension
lower arm ball joints
Front suspension
lower arm bushings
Pinch bolt on
steering column
shaft flexible coup-
ling Power
steering pres-
sure (PSP) switch
Wheels and tires
Power steering line
fluid leaks
Steering gear
bellows
3. If an obvious cause for an observed or reported
concern is found, correct the cause (if possible)
before proceeding to the next step.
4. If the cause is not visually evident, verify the
symptom and refer to the Symptom Chart.
Symptom Chart
Symptom Possible Sources Action
Drift left or right
2006.0 Fiesta 1212006 Gl49906en
Vehicle attitude incorrect (front
or rear is high or low). CHECK for abnormal loading,
coil spring sag or non-standard
springs.
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