Problems and Answers to Disc Brakes

[Offspring]

i just thought i would post a article on how to solving brake problems for my fellow 3siers. if only a mod can make this a stickie somewhere.

Problem Possible Cause Check/Correct

1. Excessive pedal travel Low brake fluid = Fill,inspect,repair,bleed sys.
Excessive rotor runout = Refinish or replace rotor.
Air in hydraulic system = Bleed brakes.
Bent brake pad and lining or worn insulators = Inspect and replace.
Loose wheel bearing = Adjust or replace.
Damaged piston seal in caliper = Replace.
Power brake inoperative = Repair or replace.
Failure to one section of the hydraulic system = Inspect,check brake light.
Caliper parking brake out of adjustment = Inspect rear caliper, repair.
Loose calipers = Tighten retaining bolts.
Floating or sliding caliper not moving freely = Inspect,clean,replace.


2. Pedal pulsations Tight caliper slides = Free,repair.
Loose wheel bearings = Adjust or replace.
Excessive rotor runout (wobble) = Refinish or replace rotor.
Rotor out of parallel (uneven rotor thickness) = Refinish or replace rotor.
Wheel and tire vibrations = Diagnose vibration.


3. Excessive pedal force, Wrong lining = Install correct lining.
Grabbing, uneven braking Lining worn or glazed = Replace pads.
Piston stuck in caliper = Service or replace caliper.
Power brake booster defective = Repair or replace.
Brake fluid,oil,grease on lining = Repair leakage, replace pads.
Failure of one section of hydraulic system = Inspect, check for brake light.


4. Pulls to one side Seized caliper = Service or replace.
While braking Piston stuck in caliper = Service or replace.
Incorrect tire pressure = Adjust.
Incorrect wheel alignment = Align.
Brake fluid,oil, or grease on lining = Repair leakage, replace pads.
Bent or warped pads = Replace.
Broken rear spring = Replace.
Restricted line or hose = Repair or replace.
Unmatching linings = Replace.
Loose Caliper = Tighten.
Loose suspension parts = Tighten.
Broken shocks = Replace shocks.


5. Fluid level low Leaks = Repair, add fluid, bleed system.
Worn lining = Replace.

[Offspring]

6. Warning light comes on while braking Low fluid = Replace.
One section of hydraulic system has failed = check both sections.
Pressure Differential Valve defective = Replace.


7. Caliper parking brake will not release Improper cable adjustment = Adjust.
Vacuum release system inoperative= Repair.


8. Caliper parking brake will not hold Ineffective rear lining = Inspect and replace.
Improper parking brake cable adjustment = Adjust.
Defective rear actuators = Adjust, repair.
Defective parking brake pedal assembly = Repair.


9. Front disc brakes grab Defective metering valve = Replace.
Incorrect brake linings = Replace.
Improper surface finish on rotor = Refinish rotor.
Contaiminated brake pad linings = Replace.


10. No braking with pedal fully depressed Low fluid in resrvoir= Add fluid.
Piston pushed back in caliper = Pump brake pedal; check brake pad position.
Leak in hydraulic system = Repair.
Damaged piston seal = Replace.
Leak past primary cup in master cylinder = Service or replace master cylinder.
Air in hydraulic system = Add fluid, bleed system.


11. Fluid leaking from caliper Damaged or worn piston seal= Replace.
Scores or corrosion on piston or in caliper bore= Service caliper.
Defective caliper seal= Rebuild or replace caliper.
Loose brake line fitting= Tighten or replace brake line.
Damaged copper sealing washer on banjo bolt=Replace copper sealing washer.


12. Brakes fail to release Power brake booster defective= Repair or replace.
Brake pedal binding = Free and repair.
Master cylinder push rod improperly adjusted = Adjust.
Driver rides pedal = Notify driver.
Incorrect stoplight switch adjustment = Adjust.
Caliper piston not retracting = Service or replace.
Speed control switch improperly adjusted = Adjust.
Incorrect parking brake adjustment = Adjust.
Restricted pipes, hoses, or banjo bolts = Repair.

[Offspring]

13. Brake noise Typical of some disc brakes = No action required.

*Frequent or continuous squeal Brake pad loose on caliper=Clinch brake pad tabs to caliper.
Worn or missing parts= Check for damaged or missing brake hardware.
Improper clearance on rear disc brakes=check clearance between rotor and lining.
Rotor scored or improperly machined= Remachine or replace rotor.
Antisqueal compound not applied to pads= Remove and apply antisqueal to back of pads.
Glazed linings= Inspect rotor; replace pads.
Rivets loose in brake pad and lining= Replace brake pads.
Typical of many disc brakes= No action required.

*Scraping Disc rubbing caliper= Remove rust or mud from caliper; tighten caliper bolts.
Loose wheel bearing= Adjust or replace.
Worn lining; wear sensor scraping on disc= Inspect disc and replace pads.
Improper assembly= Assemble properly.

*Rattle at low speed pads loose on caliper= clinch pad tabs to caliper; install new pads.
Loose antirattle clips = Adjust or tighten clips.
Loose attaching hardware = Tighten attaching hardware.

*Groan when slowly releasing brakes (creep groan) Brake pads loose on caliper=clinch tabs on caliper.

[Offspring]

that about covers it....

[bjmsam]

Originally Posted by Offspring

i just thought i would post a article on how to solving brake problems for my fellow 3siers. if only a mod can make this a stickie somewhere.

Nice! BTW, wiki > sticky.

[MichaelMR2]

A, Why do my rotors keep on cracking?
B, just got new brake kit, it vibrates when really pushing it..is this normal?

[speedy25]

One more to add to part one and maybe another section. Defective/old brake hose. As the hose STARTS to fail it can "balloon" before it finally leaks.

-SP

Originally Posted by Offspring

Problem Possible Cause Check/Correct

1. Excessive pedal travel Low brake fluid = Fill,inspect,repair,bleed sys.
Excessive rotor runout = Refinish or replace rotor.
Air in hydraulic system = Bleed brakes.
Bent brake pad and lining or worn insulators = Inspect and replace.
Loose wheel bearing = Adjust or replace.
Damaged piston seal in caliper = Replace.
Power brake inoperative = Repair or replace.
Failure to one section of the hydraulic system = Inspect,check brake light.
Caliper parking brake out of adjustment = Inspect rear caliper, repair.
Loose calipers = Tighten retaining bolts.
Floating or sliding caliper not moving freely = Inspect,clean,replace.

[Offspring]

thats a good point with the ballooning,

and to the last two questions. if you have new rotors and they are cracking its because they are not made out of good material to make rotors out of. and if it vibrates when your really pushing it, they might be a little warped

[bjmsam]

Originally Posted by Offspring

if it vibrates when your really pushing it, they might be a little warped

Then again, maybe not.