Section 06-00: Brake System—Service
1993 Mustang Workshop Manual
DIAGNOSIS AND TESTING

Power Brake Functional Test

 
 

Vacuum Booster

Inspect all hoses and connections. All unused vacuum connectors should be capped. Hoses and their connections should be properly secured and in good condition with no holes or no collapsed areas. Inspect check valve on the power unit for damage.

 

Booster Operation Check

  1. Check the hydraulic brake system for leaks or insufficient fluid.
  1. With transmission in PARK, stop engine and apply parking brake. Depress the service brake pedal several times to exhaust all vacuum in the system.
  1. With the engine turned off and all vacuum in the system exhausted, depress the service brake pedal, and hold it in the applied position. Start the engine. If the vacuum system is operating, the pedal will tend to move downward under constant foot pressure. If no motion is felt, the vacuum booster system is not functioning.
  1. Remove the vacuum hose from the brake booster check valve. Manifold vacuum should be available at the check valve end of the hose with the engine at idle speed and the transmission in NEUTRAL. Ensure that all unused vacuum outlets are properly capped, hose connectors are properly secured, and vacuum hoses are in good condition.

    When it is established that manifold vacuum is available to the booster, connect the vacuum hose to the booster and repeat Step 3. If no downward movement of the brake pedal is felt, replace the brake booster.

  1. Operate the engine a minimum of 10 seconds at fast idle. Stop the engine, and let the vehicle stand for 10 minutes. Then, depress the brake pedal with approximately 89N (20 lb) of force. The pedal feel (brake application) should be the same as that noted with the engine operating. If the pedal feels hard (no power assist), replace the check valve, then repeat the test. If pedal still feels hard, replace the brake booster.

    If the brake pedal movement feels spongy, bleed the hydraulic system to remove air from the system. Refer to Section 06-06.

    Refer to the Vacuum Brake Booster Diagnosis chart, to assist in vacuum booster diagnosis.

    Refer to the Brake System Diagnosis charts for general brake system concerns.

    Refer to the Diagnosis Index for component diagnosis.

BRAKE SYSTEM DIAGNOSIS
ConditionPossible SourceAction
  • Brakes Do Not Apply
  • Insufficient brake fluid.
  • Add fluid, bleed system, check for leaks.
 
  • Binding or damaged brake pedal linkage.
  • Service as required.
  • Excessive Pedal Travel or Pedal Goes to Floor
  • Air in system.
  • Bleed system.
 
  • Loose brake tube end fittings.
  • Tighten to specification.
 
  • Malfunctioning master cylinder.
 
  • Loose wheel bearings — Front.
  • Replace as required.
 
  • Loose or missing pedal bushings/fasteners.
  • Check and replace as required.
  • Excessive Pedal Effort to Stop Vehicle
  • Binding or damaged pedal linkage.
  • Inspect. Service as required.
 
  • Engine vacuum loss.
  • Check engine vacuum, and vacuum at check valve to booster. Service as required.
 
  • Booster inoperative.
 
  • Worn or contaminated linings.
  • Inspect. Replace if necessary.
 
  • Brake system.
  • Inspect wheel cylinders or caliper pistons, restricted lines or hoses, contaminated brake fluid, improper operation of proportioning or metering valve. Service as necessary.
  • Spongy Pedal
  • Air in system.
  • Bleed system.
 
  • Loose or improper brake pedal, pedal support, booster, master cylinder attachment.
  • Service as required.
 
  • Brake system.
  • Inspect for damaged or distorted parts in brake caliper assemblies, cracked brake drums, mis-machined anchor plates.
  • Brakes Drag, Slow or Incomplete Release
  • Parking brake cable out of adjustment or binding.
  • Check cables for correct adjustment or bind.
 
  • Front wheel bearings worn or damaged.
  • Check bearings for wear, damage or bind.
 
  • Blocked master cylinder compensator ports.
 
  • On front disc brakes — loose or missing innershoe clip.
  • Inspect and replace if required.
 
  • Brake adjustment (rear).
  • Check and adjust.
 
  • On front disc brakes — LH or RH shoes misassembled.
  • Check and service.
 
  • Restriction in hydraulic system.
  • Check and service.
 
  • Caliper piston seizure.
  • Check and service.
  • Noise at Wheels When Brakes are Applied — Snap or Clicks
  • On disc brakes — loose or missing inner anti-rattle clip.
  • Lubricate and replace. (Use Disc Brake Caliper Slide Grease D7AZ-19590-A (ESA-M1C172-A) or equivalent.)
 
  • On front disc brakes — missing pin insulator.
  • Lubricate and replace. (Use Disc Brake Caliper Slide Grease D7AZ-19590-A (ESA-M1C172-A) or equivalent.)
 
  • On front disc brakes — missing or loose pins.
  • Lubricate and replace. (Use Disc Brake Caliper Slide Grease D7AZ-19590-A (ESA-M1C172-A) or equivalent.)
  • Noise at Wheels When Brakes are Applied — Scrape or Grind
  • Worn brake linings.
  • Replace drums or rotors if heavily scored.
 
  • Caliper to wheel or rotor interference.
  • Replace as required.
 
  • Other brake system components:
    Warped or bent brake splash shield, cracked rotors.
  • Inspect and service.
 
  • Tires rubbing against chassis or body.
  • Inspect and service.
 
  • Rotor to spindle interference.
  • Replace as required.
  • Noise at Wheels When Brakes are Applied — Squeaks, Squeals, or Chatter.

    NOTE: Brake friction materials inherently generate noise and heat in order to dissipate energy. As a result, occasional squeal is normal and is aggravated by severe environmental conditions such as cold, heat, wetness, snow, salt, mud, etc. This occasional squeal is not a functional concern and does not indicate any loss of brake effectiveness.
  • Rotors and pads worn or scored.
  • Inspect, service or replace.
 
  • On disc brakes — missing or damaged brake pad insulators.
  • Replace.
 
  • On disc brakes — burred or rusted calipers.
  • Clean or deburr.
 
  • Dirty, greased, contaminated or glazed linings.
  • Clean or replace. Lightly sand off glaze.
 
  • Improper lining parts.
  • Inspect for correct usage. Replace.
  • Noise at Wheels, Brakes Not Applied — Squeak or Squeal
  • Wheelcover attachment.
  • Seat covers with a rubber mallet. Service flanges or replace cover.
 
  • Loose wheel retaining lug nuts.
  • Tighten to specification. Replace wheel if stud holes are damaged.
 
    Other brake system components:
     
    • Loose or extra parts in brakes.
    • Inspect, service or replace as required.
     
    • Worn, damaged, or insufficiently lubricated wheel bearings.
       
      • Improper positioning of shoe in caliper.
         
        • Outside diameter of rotor rubbing caliper housing.
           
          • Improper installation of disc brake anti-rattle clip.
            • Noise at Wheels, Brakes Not Applied — Growling, Click or Rattle
            • Stones or foreign material trapped inside wheelcovers.
            • Remove stones, etc.
             
            • Loose grease cap.
            • Service or replace.
             
            • Loose wheel lug nuts.
            • Tighten to specification. Replace if stud holes are elongated.
             
            • Disc brake caliper — loose or missing anti-rattle clips or support pins.
            • Inspect, service or replace.
             
            • Worn, damaged or dry wheel bearings.
            • Inspect, lubricate or replace.
            • Brakes Pull to One Side
            • Unequal air pressure in tires.
            • Inflate tires to correct pressure.
             
            • Grease or fluid on linings. Glazed linings.
            • Replace.
             
            • Loose or missing disc brake caliper retaining pins.
            • Replace missing bolts. Tighten to specification.
             
            • Improper size or type lining on one wheel.
            • Replace with correct brake lining in axle sets.
             
            • Stuck or seized calipers.
            • Service or replace.
             
            • Restricted brake lines or hoses.
            • Service or replace.
             
              Other brake system components:
               
              • Improper positioning of disc brake shoe and lining in the caliper.
              • Inspect, service or replace as required.
               
              • Damaged or worn wheel bearings.
                • Brakes Grab or Lock-up When Applied
                • Tires worn or incorrect pressure.
                • Inflate tires to correct pressure. Replace tires with worn tread.
                 
                • Grease or fluid linings — damaged linings.
                • Inspect, service or replace.
                 
                • Improper size or type of linings.
                • Replace with correct brake in axle sets.
                 
                  Other brake system components:
                   
                  • Pins for caliper attachment loose or missing.
                  • Inspect, service or replace as required.
                   
                  • Worn, damaged or dry wheel bearings.
                  • Improperly adjusted parking brake.
                  		 
                  • Brake Warning Indicator On
                  • Hydraulic system.
                   
                  • Shorted indicator circuit.
                  • Correct short in warning circuit.
                   
                  • Parking brake not returned.
                  • Refer to Parking Brake Will Not Release or Fully Return below.
                   
                  • Brake warning indicator switch.
                  • Replace.
                  • Intermittent Loss of Pedal
                  • Loose wheel bearings.
                  • Replace as required.
                  • Perform Steps under Excessive Pedal Travel or Pedal Travel Goes to Floor.
                  • Rough Engine Idle or Stall, Brakes Applied
                  • Vacuum leak in neutral switch.
                  • Check lines for leaks. Service or replace as required.
                   
                  • Vacuum booster.
                  • Check vacuum booster for internal leaks. Replace if required.
                  • Parking Brake Control Will Not Latch (Manual Release)
                  • Kinked or binding release cable.
                  • Inspect, service or replace.
                   
                  • Control assembly.
                  • Inspect, service or replace.
                  • Parking Brake Will Not Release or Fully Return (Manual Release)
                  • Cable disconnected.
                  • Connect cable or replace.
                   
                  • Control assembly binding.
                  • Service or replace.
                   
                  • Parking brake linkage binding.
                  • Service or replace.
                   
                  • Rear brakes.
                  • Check rear brakes shoe retracting springs and parking brake levers. On rear disc brakes verify levers return fully to released position. Adjust cables or service caliper as required.
                  BRAKE CONTROL VALVE DIAGNOSIS
                  ConditionPossible SourceAction
                  • Premature Front Brake Lock-up On Wet or Icy Road During Light Pedal Application and Cold Engine Fast Idle Operation
                  • Worn tires or low air pressure.
                  • Check tires and tire pressures.
                   
                  • Brake linings contaminated.
                  • Check brake linings for fluid, grease or other contamination.
                   
                  • Engine idle out of adjustment.
                  • Check and adjust engine idle for normal driving.
                  • Rear Brake Lock-up During Light Brake Pedal Force
                  • Worn tires or low air pressure.
                  • Check tires and tire pressures.
                   
                  • Brake linings contaminated.
                  • Check brake linings for fluid, grease or other contamination.
                   
                  • Brake pressure control valve assembly out of specification.
                  • Install pressure gauges in the front and rear bleeder screw ports and apply 6897 kPa (1,000 psi) to the front brake system. The rear brake system pressure must be approximately 5170-6200 kPa (750-900 psi). Replace brake pressure control valve assembly if rear brake pressure is not within specification.
                  • No Rear Brake Lock-up Under Heavy Brake Pedal Force
                  • Worn tires or low air pressure.
                  • Check tires and tire pressures.
                   
                  • Brake linings contaminated.
                  • Check brake linings for fluid, grease or other contamination.
                   
                  • Damaged brake lines or brake pressure control valve assembly out of specification.
                  • Install pressure gauges in the front and rear wheel cylinder bleeder screw ports and apply 6897 kPa (1,000 psi) to the front brake system. The rear brake system pressure must be approximately 3448-4482 kPa (500-650 psi). If no pressure is obtained, check for damaged tubing. Replace the brake pressure control valve assembly if rear brake pressure is not within specification.


                  Description Pinpoint Test
                  Vibration Diagnosis
                  Vibration/Pulsation When Brakes Are Applied A
                  Master Cylinder Diagnosis
                  Pedal Goes Down Fast B
                  Pedal Eases Down Slowly C
                  Pedal Is Low and/or Feels Spongy D
                  Pedal Effort Excessive E
                  Rear Brake Lockup During Light Brake Pedal Force F
                  Excessive and/or Erratic Pedal Travel G
                  Brake Warning Lamp On H
                  Front Brakes Drag I
                  Vacuum Brake Booster Diagnosis
                  Excessive Brake Pedal Effort or Vacuum Leaks J
                  Vacuum Brake Booster Noise K
                  Slow or Incomplete Brake Pedal Return L

                   

                  PINPOINT TEST A: VIBRATION WHEN BRAKES ARE APPLIED

                   

                  A1 VERIFY CONDITION

                  No
                  GO to A2.

                  Yes
                  REFER to Section 00-04 to service this condition first. REPEAT Step.

                   

                  A2 REAR BRAKE VIBRATION

                  No
                  GO to A3.

                  Yes
                  CHECK rear discs for excessive wear or runout. REFER to Section 06-04 for rear disc brake or Section 06-02 for rear drum brake procedures.

                   

                  A3 FRONT BRAKE VIBRATION

                  • Road test vehicle with light and medium application on the pedal.
                  • Was a vibration present?
                  No
                  Vehicle OK.

                  Yes
                  CHECK front rotors for excessive runout or cracks. REFER to Section 06-03 for disc brake rotor procedures. REPEAT Step A3.

                   

                  PINPOINT TEST B: MASTER CYLINDER DIAGNOSIS—PEDAL GOES DOWN FAST

                   

                  B1 VERIFY CONDITION

                  • Road test vehicle and depress brake pedal.
                  • Was pedal effort normal?
                  Yes
                  Vehicle OK.

                  No
                  GO to B2.

                   

                  B2 BRAKE FLUID LEVEL

                  • Check master cylinder brake fluid reservoir level.
                  • Is fluid level acceptable?
                  Yes
                  GO to B3.

                  No
                  CHECK reservoir sealing points (use Diagnostic Technique No. 3 ), ADD fluid and BLEED system. REPEAT Test B1.

                   

                  B3 PRESSURIZE SYSTEM

                  • Pump brake pedal rapidly (five times).
                  Pedal height builds up, then sinks
                  GO to B4.

                  Pedal height builds up and holds
                  CHECK rear brake adjustment and ADJUST if necessary. If condition still exists, BLEED system for air. REPEAT Test B1.

                   

                  B4 BRAKE SYSTEM LEAKS

                  • Any leaks found?
                  No
                  GO to B5.

                  Yes
                  SERVICE as necessary, ADD fluid and BLEED system. REPEAT Test B1.

                   

                  B5 MASTER CYLINDER BYPASS TEST

                  • Was a problem found?
                  No
                  System OK.

                  Yes
                  REPLACE damaged parts, ADD fluid and BLEED system. REPEAT Test B1.

                   

                  PINPOINT TEST C: MASTER CYLINDER DIAGNOSIS—PEDAL EASES DOWN SLOWLY

                   

                  C1 VERIFY CONDITION

                  • Check if condition occurs during actual stopping application by depressing the brake pedal while the vehicle is moving.
                  Condition occurs only when vehicle is stationary
                  No action required. (SEE Normal Condition No.1)

                  Condition occurs while vehicle is moving and braking performance is affected
                  GO to C2.

                   

                  C2 BRAKE SYSTEM LEAKS

                  • Were any leaks found?
                  No
                  GO to C3.

                  Yes
                  SERVICE as necessary. ADD fluid and BLEED system. REPEAT Test C1.

                   

                  C3 MASTER CYLINDER BYPASS TEST

                  • Was a problem found?
                  No
                  System OK.

                  Yes
                  REPLACE damaged parts, ADD fluid and BLEED system. REPEAT Test C1.

                   

                  PINPOINT TEST D: MASTER CYLINDER DIAGNOSIS—PEDAL IS LOW AND/OR FEELS SPONGY

                   

                  D1 VERIFY CONDITION

                  • Road test vehicle and apply brake pedal.
                  • Was pedal effort normal?
                  Yes
                  Vehicle OK.

                  No
                  GO to D2 .

                   

                  D2 BRAKE FLUID LEVEL CHECK

                  • Check master cylinder brake fluid reservoir level.
                  • Is fluid level acceptable?
                  Yes
                  GO to D3 .

                  No
                  CHECK reservoir sealing points. (USE Diagnostic Technique No. 3). ADD fluid and BLEED system.

                   

                  D3 FILLER CAP VENT CHECK

                  • Check if filler cap vent holes are clogged or dirty.
                  • Was a concern found?
                  No
                  GO to D4 .

                  Yes
                  CLEAN as necessary. REPEAT Test D1 .

                   

                  D4 BLEED BRAKE SYSTEM

                  • Bleed brake system as described in this section.
                  • Is condition still present?
                  No
                  Vehicle OK.

                  Yes
                  GO to D5 .

                   

                  D5 FRONT HUB NUT CHECK

                  • Check front wheel hub nut for looseness (Refer to Section 04-01).
                  • Was hub nut loose?
                  No
                  CHECK rear brake adjustment and ADJUST if necessary. REPEAT Test D1 .

                  Yes
                  REPLACE with new nut and stake. Do not reuse the nut. REPEAT Test D1 .

                   

                  PINPOINT TEST E: MASTER CYLINDER DIAGNOSIS—PEDAL EFFORT EXCESSIVE

                   

                  E1 VERIFY CONDITION

                  • Depress brake pedal fully several times.
                  Pedal is good
                  Vehicle is OK.

                  Pedal has long stroke and requires excessive effort
                  GO to E2.

                   

                  E2 FLUID CONTROL VALVE CHECK

                  • Check fluid control valve for contamination. (Refer to Fluid Control Valve Assembly procedure in this section.)
                  • Is fluid contaminated?
                  No
                  GO to E3.

                  Yes
                  REPLACE valve. FILL reservoir. REPEAT Test E1.

                   

                  E3 BRAKE PEDAL LINKAGE TEST

                  • Detach booster push rod from pedal pin and depress brake pedal fully.
                  • Did pedal move freely?
                  Yes
                  CHECK booster vacuum availability as described under Vacuum Booster Diagnosis in this Section.

                  No
                  SERVICE or REPLACE brake pedal linkage. REPEAT Test E1.

                   

                  PINPOINT TEST F: MASTER CYLINDER DIAGNOSIS—REAR BRAKE LOCKUP DURING LIGHT BRAKE PEDAL FORCE

                   

                  F1 VERIFY CONDITION

                  • Road test vehicle and apply brakes lightly.
                  • Do brakes lockup?
                  No
                  Vehicle OK.

                  RH rear lockup
                  GO to F4.

                  LH rear lockup
                  GO to F5.

                  Both lockup
                  PERFORM Tests F4 and F5.

                   

                  F2 TIRE INSPECTION

                  • Check for excessive tire wear or improper tire pressures.
                  • Are tires good?
                  Yes
                  GO to F3.

                  No
                  SUBSTITUTE known good tires if worn. INFLATE to proper pressure. REPEAT Test F1.

                   

                  F3 BRAKE PAD INSPECTION

                  • Inspect brake shoes and linings for grease or fluid and/or wear concerns.
                  • Are there concerns?
                  Yes
                  GO to F4.

                  No
                  REPLACE if necessary. REPEAT Test F1.

                   

                  F4 PRESSURE CONTROL VALVE TEST—RH REAR

                  • Install pressure gauges in the LH front and RH rear bleeder screws. Apply 6895 kPa (1000 psi) in front brake system. The rear brake pressure must be between 4692-5164 kPa (680-750 psi).
                  • Is rear brake pressure between 4692-5164 kPa (680-750 psi)?
                  Yes
                  INSPECT parking brake and ADJUST as required.

                  No
                  REPLACE RH rear valve.

                   

                  F5 PRESSURE CONTROL VALVE TEST—LH REAR

                  • Install pressure gauges in RH front and LH rear bleeder screws. Apply 6895 kPa (1000 psi) in front brake system. The rear brake pressure must be between 3964-4343 kPa (575-630 psi).
                  • Is rear brake pressure between 3964-4343 kPa (575-630 psi)?
                  Yes
                  INSPECT parking brake and ADJUST as required.

                  No
                  REPLACE LH rear valve.

                   

                  PINPOINT TEST G: MASTER CYLINDER DIAGNOSIS—EXCESSIVE AND/OR ERRATIC PEDAL TRAVEL

                   

                  G1 ROUGH ROAD TEST

                  • Road test vehicle under rough road conditions. Apply brakes slowly.
                  • Are brakes good?
                  Yes
                  Vehicle OK.

                  No
                  GO to G2.

                   

                  G2 WHEEL BEARING CHECK

                  • Check for loose wheel bearings.
                  • Are wheel bearings loose?
                  Yes
                  REPLACE wheel bearing if damaged. TIGHTEN wheel bearing assembly to specification. REPEAT Test G1.

                  No
                  CHECK rotor for thickness variances. (REFER to Section 06-03 for front disc overhaul procedures).

                   

                  PINPOINT TEST H: MASTER CYLINDER DIAGNOSIS—BRAKE WARNING LAMP ON

                   

                  H1 BRAKE FLUID LEVEL  

                  • Check master cylinder brake fluid reservoir level.
                  • Is fluid level good?
                  Yes
                  GO to H3.

                  No
                  GO to H2.

                   

                  H2 BRAKE SYSTEM LEAKAGE

                  • Check reservoir sealing points and external brake system for leakage. (Refer to Diagnostic Technique No.1 and Diagnostic Technique No.3).
                  • Does system leak?
                  Yes
                  SERVICE as necessary, ADD fluid and BLEED system.

                  No
                  FILL reservoir. GO to H3.

                   

                  H3 IGNITION WIRING CHECK

                  • Check that ignition wiring is not within a 50.8mm (2-inches) radius of the reed switch Fluid Level Indicator (FLI) assembly.
                  • Is ignition wiring good?
                  Yes
                  GO to H4.

                  No
                  REROUTE wiring as necessary.

                   

                  H4 FLOAT ASSEMBLY CHECK

                  • Check if float is stuck or if magnet is dislodged from float.
                  • Is float functional?
                  Yes
                  CHECK if ignition prove out circuit is working properly.

                  No
                  REPLACE reservoir assembly.

                   

                  PINPOINT TEST I: MASTER CYLINDER DIAGNOSIS—FRONT BRAKES DRAG

                   

                  I1 VACUUM BOOSTER CHECK

                  • Check vacuum booster push rod adjustment.
                  • Is push rod within specification?
                  Yes
                  INSPECT fluid control valve for contamination. (REFER to Fluid Control Valve Assembly procedure in this section). REPEAT I1 .

                  No
                  SERVICE/ADJUST push rod as required. REPEAT Test Step I1 .

                   

                  PINPOINT TEST J: EXCESSIVE BRAKE PEDAL EFFORT OR VACUUM LEAKS

                   

                  J1 VERIFY CONDITION

                  • With engine off, depress and release brake pedal five times to deplete all vacuum from booster. Depress pedal, hold with light pressure. Start engine.
                  • Does pedal fall slightly then hold?
                  Yes
                  GO to J2.

                  No
                  GO to J4.

                   

                  J2 VACUUM BOOSTER LEAK TEST

                  • Run engine to medium speed, release accelerator and turn engine off. Wait 90 seconds and apply brakes. Two or more applications should be power assisted.
                  • Does vacuum booster work?
                  Yes
                  Vehicle OK.

                  No
                  GO to J3.

                   

                  J3 POWER SECTION CHECK VALVE TEST

                  • Disconnect vacuum hose for booster check valve at manifold. Blow into hose attached to check valve.
                  • Does air pass through valve?
                  Yes
                  INSTALL new check valve and REPEAT Step J2.

                  No
                  REPLACE booster. REPEAT Step J1.

                   

                  J4 POWER SECTION TEST

                  • Disconnect vacuum hose from booster vacuum check valve. Run engine at idle. Check vacuum supply with a vacuum gauge.
                  • Does gauge indicat above 40.5 kPa (12 in-Hg)?
                  Yes
                  REPLACE booster. REPEAT Step J1.

                  No
                  SERVICE or REPLACE vacuum hose and vacuum fittings. Also TUNE or SERVICE engine as required. REPEAT Step J1.

                   

                  PINPOINT TEST K: VACUUM BRAKE BOOSTER NOISE

                   

                  K1 VERIFY CONDITION

                  • Run engine at fast idle for 10 seconds or longer. Depress brake pedal and listen for noise. Compare results with known good system.
                  • Was a noise present?
                  Yes
                  GO to K2.

                  No
                  Vehicle OK.

                   

                  K2 PUSH ROD ADJUSTMENT

                  • Check and adjust booster push rod.
                  • Is push rod adjustment OK?
                  Yes
                  BLEED brake system.

                  No
                  REPLACE booster. REPEAT Step K1.

                   

                  PINPOINT TEST L: SLOW OR INCOMPLETE BRAKE PEDAL RETURN

                   

                  L1 VERIFY CONDITION

                  • Run engine at fast idle while making several brake applications. Pull brake pedal rearward with approximately 44.5 N (10 lbs) force. Release the pedal and measure the distance to the toe board. Make a heavy brake application. Release the brake pedal and measure the pedal to toe board distance. The pedal should return to its original position.
                  • Did pedal return to original position?
                  Yes
                  Vehicle OK.

                  No
                  GO to L2.

                   

                  L2 BRAKE PEDAL BINDING

                  • Check pedal to be sure it is operating freely.
                  • Is the pedal operating freely?
                  Yes
                  REPLACE booster.

                  No
                  CORRECT any sticking or binding. REPEAT L1.