Ford Workshop Service and Repair Manuals

NOTE:Prior to performing any diagnosis, make sure that the brake system warning indicator is functioning.

Visually examine front and rear tires and wheel assemblies for damage such as uneven wear patterns, tread worn out or sidewall damage. Make sure the tires are of the same size, type and, where possible, same manufacture. Install a new tire or wheel that is damaged or excessively worn. REFER to Section  204-04 Wheels and Tires.

Wheels and tires must be cleared of any foreign material and tire pressures adjusted to the correct specification.

If tires exhibit uneven wear or feathering, the cause must be corrected. Check steering and suspension components for damage or wear and, if necessary, check and adjust front alignment. REFER to Section  204-00 Suspension System - General Information.

Road Test

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.

The driver should have a thorough knowledge of brake system operation and accepted general performance guidelines to make good comparisons and detect performance concerns.

An experienced brake 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's experience will allow the technician to match possible causes with symptoms. Certain components will be tagged as possible suspects while others will be eliminated by the evidence. More importantly, the customer's description can reveal unsafe conditions which should be checked or corrected before the 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. Keeping the description in mind, test the brakes at different vehicle speeds using both light and heavy pedal pressure. To determine if the concern is in the front or rear braking system, first use the service brake pedal and then use the parking brake. If the condition (pull, vibration, pulsation) occurs only with the parking brake, the concern is in the rear brake system. If the condition occurs when the service brake pedal is pressed, the concern is in the front brake system.

Avoid locking the brakes and sliding the tires. Locked brakes and sliding tires do not indicate brake efficiency. A heavily braked and turning wheel will stop the vehicle in a shorter distance than locked brakes.

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.

Symptom Chart

Pinpoint Tests

PINPOINT TEST A : BRAKES PULL OR DRIFT
TEST CONDITIONS	DETAILS/RESULTS/ACTIONS
A1: ROAD TEST VEHICLE
	1 Road test vehicle and apply brake pedal.
	Does vehicle pull or drift? Yes GO to A2. No Vehicle OK.
A2: TIRE INSPECTION
	1 Check for excessive wear or incorrect tire pressure.
	Are tires good? Yes GO to A3. No INFLATE tires to proper pressure. INSTALL new tires if excessively worn. REPEAT the road test if necessary.
A3: BRAKE SHOE AND LINING INSPECTION
	1 Inspect brake shoe for grease or fluid on linings and wear concerns.
	Are any concerns present? Yes INSTALL a new brake shoe. No GO to A4.
A4: PRESSURE CONTROL VALVE TEST – RIGHT-HAND REAR
	1 Install pressure gauges in left-hand front and right-hand rear bleeder screws. Apply brake to read 6895 kPa (1000 psi) at left-hand front wheels. Rear pressure at right-hand rear wheel.
	Does pressure gauge read between 4692-5164 kPa (680-750 psi) at right-hand rear wheel? Yes INSPECT and INSTALL new calipers as required. GO to A5. No RENEW right-hand rear brake pressure control valve. GO to A5.
A5: PRESSURE CONTROL VALVE TEST – LEFT-HAND REAR
	1 Install pressure gauges in right-hand front and left-hand rear bleeder screws. Apply brake to read 6895 kPa(1000 psi) at right-hand front wheel. Read pressure at left-hand rear wheel.
	Does pressure gauge read between 4692-5164 kPa (680-750 psi) at left-hand rear wheel? Yes INSPECT calipers and INSTALL a new as required. No INSTALL a new left-hand rear brake pressure control valve.

PINPOINT TEST B : BRAKE WARNING INDICATOR ALWAYS ON
TEST CONDITIONS	DETAILS/RESULTS/ACTIONS
B1: BRAKE WARNING LAMP TEST
NOTE:The brake warning lamp should only light in a normal system when the ignition switch is in START position or when the ignition switch is in RUN and the parking brake is applied.
	1 Release parking brake. Check fluid level in reservoir. Fill as required. Ignition switch in START or RUN.
	Does brake warning lamp illuminate? Yes GO to B2. No GO to B4.
B2: BRAKE SYSTEM LEAKAGE
	1 Check brake master cylinder reservoir sealing points and external brake system for leakage. (Refer to Component Tests – Brake Master Cylinder Non-Pressure Leaks check.)
	Does system leak? Yes SERVICE as necessary. ADD fluid and BLEED system. REFER to Section  206-00 Brake System - General Information. No FILL the brake master cylinder reservoir. GO to B3.
B3: BRAKE WARNING SWITCH WIRING
	1 Partially drain the brake master cylinder. Turn ignition switch to RUN and observe brake warning lamp.
	Does the brake warning lamp illuminate? Yes FILL the brake master cylinder reservoir, switch/wiring OK. TEST the system for normal operation. No CHECK for open in brake warning switch to brake warning lamp wiring. SERVICE as required. If no open found, GO to B4.
B4: BRAKE WARNING SWITCH CHECK
	1 Manually push the float in the reservoir to the bottom. Turn ignition switch to RUN and observe the brake warning lamp.
	Does the brake warning lamp illuminate? Yes REFILL reservoir, brake warning switch OK. TEST the system for normal operation. No INSTALL a new brake master cylinder reservoir. REFER to Section  206-06 Hydraulic Brake Actuation.

PINPOINT TEST C : VIBRATION WHEN BRAKES ARE APPLIED
TEST CONDITIONS	DETAILS/RESULTS/ACTIONS
C1: ROAD TEST
	1 Road test vehicle without applying brakes 40-80 km/h (25-50 mph).
	Is a vibration present? Yes Inspect vehicle for vibration. REFER to Section  100-04 Noise, Vibration and Harshness. No GO to C2.
C2: CHECK FOR REAR BRAKE VIBRATION
NOTE:With manual release parking brake control, hold the parking brake control in release position during parking brake control application.
	1 Road test vehicle with medium application on the parking brake control only.
	Is a vibration present? Yes CHECK rear disc brake or drum for excessive wear or runout. REFER to Section  206-00 Brake System - General Information. No GO to C3.
C3: CHECK FOR FRONT BRAKE VIBRATION
	1 Road test vehicle with light and medium application on the brake pedal.
	Is a vibration present? Yes CHECK front disc brake for excessive runout or cracks. REFER to Section  206-00 Brake System - General Information. No Vehicle OK.

PINPOINT TEST D : PEDAL GOES DOWN FAST
TEST CONDITIONS	DETAILS/RESULTS/ACTIONS
D1: CHECK PEDAL FEEL
	1 Road test vehicle and apply brake pedal.
	Was brake pedal effort normal? Yes Vehicle OK. No GO to D2.
D2: CHECK BRAKE FLUID LEVEL
	1 Check brake master cylinder reservoir fluid level.
	Is fluid level acceptable? Yes GO to D3. No CHECK brake master cylinder reservoir sealing points (use Component Tests – Brake Master Cylinder Non-Pressure Leaks check). ADD fluid and BLEED system.
D3: PRESSURIZE SYSTEM
	1 Pump brake pedal rapidly (five times).
	Does the brake pedal height build up and then hold? Yes CHECK rear brake adjustment and ADJUST if necessary. If condition still exists. BLEED system for air. REFER to Section  206-00 Brake System - General Information. No GO to D4.
D4: CHECK FOR BRAKE SYSTEM LEAKS
	1 Check for external brake system leaks (refer to Component Test – Brake Master Cylinder Non-Pressure Leaks check).
	Are leaks found? Yes SERVICE as necessary, ADD fluid and BLEED system. REFER to Section  206-00 Brake System - General Information. No GO to D5.
D5: PERFORMANCE CYLINDER BYPASS CONDITION CHECK
	1 Test for brake master cylinder bypass (refer to Component Tests – Brake Master Cylinder Bypass Condition Test).
	Was a concern found? Yes INSTALL a new brake master cylinder, ADD fluid and BLEED system. REFER to Section  206-00 Brake System - General Information. No System OK.

PINPOINT TEST E : PEDAL EASES DOWN SLOWLY
TEST CONDITIONS	DETAILS/RESULTS/ACTIONS
E1: CHECK BRAKE PEDAL OPERATION
	1 Check if condition occurs during actual stopping when applying the brake pedal while the vehicle is moving.
	Does condition occur with vehicle stationary? Yes No No action required. (REFER to Component Tests – Brake Master Cylinder Abnormal Conditions.)
E2: CHECK FOR BRAKE SYSTEM LEAKS
	1 Check for external brake system leaks (refer to Component Tests – Brake Master Cylinder Non-Pressure Leaks checks).
	Are any leaks found? Yes SERVICE as necessary. ADD fluid and BLEED system. REFER to Section  206-00 Brake System - General Information. No GO to E3.
E3: PERFORM BRAKE MASTER CYLINDER BYPASS TEST
	1 Test for brake master cylinder bypass (refer to Component Tests – Brake Master Cylinder Bypass Condition Test).
	Was a concern found? Yes INSTALL a new brake master cylinder, ADD fluid and BLEED system. REFER to Section  206-06 Hydraulic Brake Actuation. No System OK.

PINPOINT TEST F : PEDAL IS LOW OR FEELS SPONGY
TEST CONDITIONS	DETAILS/RESULTS/ACTIONS
F1: CHECK FOR SPONGY PEDAL
	1 Road test vehicle and apply brake pedal.
	Was brake pedal effort normal? Yes Vehicle OK. No GO to F2.
F2: BRAKE FLUID LEVEL CHECK
	1 Check brake master cylinder reservoir fluid level.
	Is fluid level acceptable? Yes GO to F3. No CHECK brake master cylinder reservoir sealing points. (USE Components Tests – Brake Master Cylinder Non-Pressure Leaks check). ADD fluid and BLEED system.
F3: FILLER CAP VENT CHECK
	1 Check if filler cap vent holes are clogged or dirty.
	Was a concern found? Yes CLEAN as necessary. No GO to F4.
F4: BLEED BRAKE SYSTEM
	1 BLEED brake system. REFER to Section  206-00 Brake System - General Information.
	Is condition still present? Yes GO to F5. No Vehicle OK.
F5: FRONT HUB NUT CHECK
	1 Check front axle wheel hub retainer nut for looseness. REFER to Section  204-01 Front Suspension.
	Was front axle wheel hub retainer nut loose? Yes INSTALL a new front axle wheel hub retainer. Do not reuse the front axle wheel hub retainer. No CHECK rear brake adjustment and ADJUST if necessary.

PINPOINT TEST G : BRAKE LOCKUP DURING LIGHT BRAKE PEDAL FORCE
TEST CONDITIONS	DETAILS/RESULTS/ACTIONS
G1: BRAKE LOCK UP TEST
	1 Road test vehicle and apply brake pedal lightly.
	Do rear brakes lock up? Yes GO to G2. No Vehicle OK.
G2: TIRE INSPECTION
	1 Check for excessive tire wear or incorrect tire pressures.
	Are tires good? Yes GO to G3. No SUBSTITUTE known good tires if worn. INFLATE to correct pressure.
G3: BRAKE PAD INSPECTION
	1 Inspect brake shoes for grease or fluid on linings and wear concerns.
	Are there concerns? Yes SERVICE or INSTALL a new brake shoes if necessary. No GO to G4.
G4: PRESSURE CONTROL VALVE TEST – RIGHT-HAND REAR
	1 Install pressure gauges in left-hand front and right-hand rear bleeder screws. Apply brake to read 6895 kPa (1000 psi) at left-hand front wheel. Read pressure at right-hand rear wheel.
	Does pressure gauge read between 4692-5164 kPa (680-750 psi) at right-hand rear wheel? Yes INSPECT calipers and INSTALL new calipers as required. GO to G5. No INSTALL a new right-hand rear brake pressure control valve. GO to G5.
G5: PRESSURE CONTROL VALVE TEST – LEFT-HAND REAR
	1 Install pressure gauges in right-hand front and left-hand rear bleeder screws. Apply brake to read 6895 kPa (1000 psi) at right-hand front wheel. Read pressure at left-hand rear wheel.
	Does pressure gauge read between 4692-5164 kPa (680-750 psi) at left-hand rear wheel? Yes INSPECT calipers and INSTALL new calipers as required. No INSTALL a new left-hand rear brake pressure control valve.

PINPOINT TEST H : EXCESSIVE/ERRATIC PEDAL TRAVEL
TEST CONDITIONS	DETAILS/RESULTS/ACTIONS
H1: ROUGH ROAD TEST
	1 Road test vehicle under rough road conditions. Apply brakes slowly.
	Are brakes good? Yes VEHICLE OK. No GO to H2.
H2: WHEEL BEARING CHECK
	1 Check for loose front wheel bearings.
	Are front wheel bearings loose? Yes INSTALL a new front wheel bearing if damaged. No CHECK front disc brake for thickness variances. REFER to Section  206-00 Brake System - General Information.

PINPOINT TEST I : BRAKES DRAG
TEST CONDITIONS	DETAILS/RESULTS/ACTIONS
I1: ROAD TEST VEHICLE
	1 Road test vehicle and apply brakes.
	Are brakes functioning properly? Yes Vehicle OK. No INSPECT individual wheel cylinders or calipers for binding/sticking components. REFER to Section  206-02 Drum Brake. (rear drums). REFER to Section  206-03 Front Disc Brake. (front discs). REFER to Section  206-04 Rear Disc Brake. (rear discs).
I2: CHECK POWER BRAKE BOOSTER
	1 Check power brake booster push rod alignment and travel.
	Is push rod OK? Yes Vehicle OK. No REPLACE power brake booster.

PINPOINT TEST J : EXCESSIVE BRAKE PEDAL EFFORT
TEST CONDITIONS	DETAILS/RESULTS/ACTIONS
J1: CHECK BRAKE APPLICATION
	1 With engine off, apply and release brake pedal five times to deplete all vacuum from power brake booster. Apply brake pedal, hold with light pressure. Start engine.
	Does the brake pedal hold? Yes GO to J2. No GO to J4.
J2: VACUUM BOOSTER LEAK TEST
	1 Run engine to medium idle, release accelerator pedal and shaft and turn engine off. Wait 90 seconds and apply brakes. Two or more applications should be power assisted.
	Does power brake booster work? Yes Vehicle OK. No GO to J3.
J3: POWER BRAKE BOOSTER CHECK VALVE TEST
	1 Disconnect vacuum hose for power brake booster check valve at manifold. Blow into hose attached to power brake booster check valve.
	Does air pass through valve? Yes INSTALL a new power brake booster check valve. No INSTALL a new power brake booster.
J4: BRAKE PEDAL LINKAGE TEST
	1 Detach booster push rod from pedal pin and apply brake pedal fully.
	Did pedal move freely? Yes GO to J5. No SERVICE or INSTALL a new brake pedal bushings.
J5: BRAKE PRESSURE CONTROL VALVE CHECK
	1 Check brake pressure control valve for contamination.
	Is fluid contaminated? Yes INSTALL a new brake pressure control valve. FILL the brake master cylinder reservoir. No GO to J6.
J6: POWER BRAKE BOOSTER CHECK VALVE VACUUM TEST
	1 Disconnect vacuum hose from power brake booster check valve. Run engine at idle. Check supply with a vacuum gauge.
	Is vacuum pressure above 40.5 kPa (12 in-Hg) with brake booster non-operational? Yes GO to Component Tests in this section to test power brake booster. No SERVICE or INSTALL a new vacuum hose and vacuum fittings. Also TUNE or SERVICE engine as required.

PINPOINT TEST K : BRAKE NOISE
TEST CONDITIONS	DETAILS/RESULTS/ACTIONS
K1: CHECK FOR PEDAL NOISE
	1 Inspect brake pads and shoes for excessive wear. Run engine at idle for 10 seconds or longer. Apply brake pedal and listen for noise. Compare results with known good system.
	Was a noise present? Yes GO to K2. No Vehicle OK.
K2: CHECK PUSH ROD ALIGNMENT
	1 Check power brake booster push rod alignment and travel.
	Is push rod OK? Yes BLEED brake system. REFER to Section  206-06 Hydraulic Brake Actuation. No INSTALL a new power brake booster.

PINPOINT TEST L : SLOW OR INCOMPLETE BRAKE PEDAL RETURN
TEST CONDITIONS	DETAILS/RESULTS/ACTIONS
L1: CHECK FOR BRAKE PEDAL RETURN
	1 Run engine at fast idle while making several brake applications. Pull brake pedal rearward with approximately 44.5 N (10 lbs) force. Release the brake pedal and measure the distance to the toe board. Make a hard brake application. Release the brake pedal and measure the brake pedal to toe board distance. The brake pedal should return to its original position.
	Did brake pedal return to original position? Yes Vehicle OK. No GO to L2.
L2: CHECK FOR BRAKE PEDAL BINDING
	1 Check brake pedal to be sure it is operating freely.
	Is the brake pedal operating freely? Yes INSTALL a new power brake booster. No SERVICE or INSTALL a new brake pedal bushings.