Rapid Brake Pad Wear, Vehicle Vibration (After A Long Drive), Or High, Hard Brake Pedal
Note. Make Sure That The Caliper Pins Are Installed Correctly.
Upper Caliper Pin A And Lower Caliper Pin B Are Different. If The Pins Are Installed In The Wrong Location, It Will Cause Vibration, Uneven Or Rapid Brake Pad Wear, And Possibly Uneven Tire Wear. For Proper Caliper Pin Location (See front Brake Caliper Overhaul ).
- Drive The Vehicle Until The Brakes Drag Or Until The Pedal Is High And Hard. This Can Take 20 Or More Brake Pedal Applications During An Extended Test-Drive.
- With The Engine Running, Raise The Vehicle On A Lift, And Spin All Four Wheels By Hand. Is There Brake Drag At Any Of The Wheels? Yes -Go To Step 3. No -Look For Other Causes Of Pad Wear, High Pedal, Or Vehicle Vibration.
- Turn The Ignition Switch To Lock (0), Press The Brake Pedal Several Times To Deplete The Vacuum In The Brake Booster, And Then Spin The Wheels Again To Check For Brake Drag. Is There Brake Drag At Any Of The Wheels? Yes -Go To Step 4. No -Replace The Brake Booster (See «master Cylinder/Brake Booster Replacement»(ref-351950-S06990154802009122900000) ).
- Without Removing The Brake Lines, Unbolt And Separate The Master Cylinder From The Brake Booster, Then Spin The Wheels To Check For Brake Drag. Is There Brake Drag At Any Of The Wheels? Yes -Go To Step 5. No -Check The Brake Pedal Position Switch Adjustment, And Pedal Free Play (See «brake Pedal And Brake Pedal Position Switch Adjustment»(ref-351950-S27484223032009122900000) ).
- Loosen The Hydraulic Lines At The Master Cylinder, Then Spin The Wheels To Check For Brake Drag. Is There Brake Drag At Any Of The Wheels? Yes -Go To Step 6. No -Check The Master Cylinder Reservoir For Contamination In The Brake Fluid. If You Find Contamination, Flush The Entire Brake System Of All Contaminated Fluid. If The Brake Fluid Is Ok, Replace The Master Cylinder (See «master Cylinder/Brake Booster Replacement»(ref-351950-S06990154802009122900000) ).
- Loosen The Bleed Screws At Each Caliper, Then Spin The Wheels To Check For Brake Drag. Is There Brake Drag At Any Of The Wheels? Yes -Check The Master Cylinder Reservoir For Contamination In The Brake Fluid. If You Find Contamination, Flush The Entire Brake System Of All Contaminated Fluid. If The Brake Fluid Is Ok, Disassemble And Repair The Caliper On The Wheel(S) With Brake Drag. No -Look For And Replace Any Damaged Brake Lines. If All Brake Lines Are Ok, Replace The Abs Or Vsa Modulator-Control Unit: Abs (See «Abs Modulator-Control Unit Removal And Installation»(ref-221358-S08388719102006022400000) ), Vsa (See «Vsa Modulator-Control Unit Removal And Installation»(ref-351947-S22392183842009122900000) ).
Scheme 49
Scheme 50
Scheme 51
- Turn The Brake Pedal Position Switch (A) Counterclockwise, And Pull It Back Until It Is No Longer Touching The Brake Pedal.
- Pull Back The Carpet, And Find The Cutout (B) In The Insulation. Measure The Pedal Height (C) At The Center Of The Pedal Pad (D) To The Floor Without The Insulation. Standard Pedal Height (With Carpet Removed): 179 Mm (7 1/16 In.)
- Loosen The Pushrod Locknut (A), And Screw The Pushrod (B) In Or Out With Pliers, Until The Standard Pedal Height From The Floor Is Reached. After Adjustment, Tighten The Locknut Firmly. Do Not Adjust The Pedal Height With The Pushrod Pressed. Brake Pedal Position Switch Clearance
- Screw In The Brake Pedal Position Switch Until Its Plunger Is Fully Pushed In (Threaded End (A) Touching The Pad (B) On The Pedal Arm). Then Back Off The Switch 1/4 Turn To Make 0.3 Mm (0.01 In.) Of Clearance Between The Threaded End And The Pad. Tighten The Locknut Firmly. NOTE: The Brakes Will Drag If There Is No Clearance. Connect The Brake Pedal Position Switch Connector. Make Sure That The Brake Lights Go Off When The Pedal Is Released.
- Check The Brake Pedal Free Play.