2003 FORD MUSTANG check engine

PINPOINT TEST F: HYDRO-
BOOST ERRATIC OPERATION, STICKS,
BINDS OR GRABS z
Check accessory drive belt tension and
condition. Refer to Section 303 - 05 .
z Is the accessory drive belt OK? Yes
GO to
E3 .
No
INSTALL a new accessory drive belt.
REFER to Section 303 - 05 .
E3 CHECK POWER STEERING HOSES
z
Check power steering pressure hoses, power
steering gear pressure hoses and power
steering return hose for cracks or leaks.
z Do power steering pressure hose, power
steering gear hose and power steering
return hose check OK? Yes
GO to
E4 .
No
INSTALL new hoses as necessary.
REFER to Section 211 - 00 .
E4 CHECK BRAKE PEDAL LINKAGE
z
Check brake pedal linkage for binding or
sticking operation.
z Does pedal linkage check OK? Yes
GO to
E5 .
No
INSTALL new pedal linkage as necessary.
REFER to Section 206 - 06 .
E5 CHECK POWER STEERING PUMP SPEED
z
Check engine idle speed against
specifications.
z Is engine idle speed OK? Yes
GO to
E6 .
No
SET engine idle speed to specification.
REFER to Powertrain Control/Emissions
Diagnosis (PC/ED) manual. E6 CHECK FOR PLUGGED RETURN HOSE
z
NOTE: The return hose from the oil cooler to
the power steering reservoir has an in- line
filter in the hose.
z Disconnect power steering return hose from
power steering fluid cooler and power
steering pump reservoir.
z Pass air through hose from the oil cooler end.
z Is hose plugged? Yes
INSTALL a new power steering return
hose.
No
GO to
E7 .
E7 CHECK POWER STEERING PUMP FLOW
AND RELIEF z
Test power steering pump for correct flow
and relief pressure. Refer to Section 211 - 00 .
z Is power steering pump operating
correctly? Yes
INSTALL a new power brake hydro-
boost
unit. REFER to Section 206 - 07 .
No
INSTALL a new power steering pump.
REFER to Section 211 - 02 .
Test Step Result / Action to
Take F1 CHECK SUPPLY HOSE
z
Check for obstructions in power steering return hose and Yes Klj . 11 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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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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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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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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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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