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Brakes FAQ

11K views 3 replies 4 participants last post by  Chunkryan 
#1 ·
Many questions come up regularly regarding brakes and related issues. I came across the following information contained within a traders magazine, so have typed it out below as it may be relevant to you and also fellow members.

Excessive Temperature & Rapid Wear
Fault;
Friction material overheating and disc surface thermal cracks (blueing)
Causes;
Sticking brake calipers (sliders/piston seals), Axle/Wheel imbalance, Excessive prolonged braking (drag)

Friction Material Fractures
Fault;
Friction material cracks/fractures
Causes;
Pad restriction within caliper housing (flexing of pad/backplate(s)), impact damage during installation

New Pads Fitted On Worn Discs
Fault;
Rapid wear, noise and judder
Causes;
Excessively worn/grooved brake disc surface

Brake Disc Contamination
Fault;
Low brake efficiency
Causes;
Contaminated disc surfaces, (oils, solvents, cleaners)

Uneven Pad Wear
Faults;
Uneven pad wear
Causes;
Poor alignment of brake caliper, poor alignment of brake disc/hub
Fault;
Uneven pad wear between 'inboard and outboard' pads
Causes;
Sticking brake caliper (insufficient lubrictaion of caliper sliders), worn/damaged piston seals

Brake Noise & Judder
Faults;
Brake noise and judder
Causes;
Dirty wheel hub

Brake Noise
Faults;
Brake noise
Causes;
Pads are tight in caliper (see scratch mark evidence on pad backplate edges). Uneven pad/disc contact, worn/grooved brake discs, excessively corroded brake discs.

Recommended Maximum Disc Run-Out
Good Practice;
Always remember to check disc run-out before fitting new brake pads. (Maximum disc run-out on vehicle 01.5mm)
Problems;
Excessive run-out will cause noise, judder, uneven pad wear and poor brake efficiency.

Brake Disc Damage
Faults;
Thermal Cracks (Blueing)
Causes;
Rapid pad wear, brake judder, vehicle vibration and brake noise.

Brake Disc Failure
Faults;
Top Hat detachment
Causes;
Overtightening of wheel nuts (careful use of air pressure guns is required)

Friction Material Detachements
Faults;
Friction material detachment
Causes;
Impact damage during pad removal/installation and/or excessive corrosion.
 
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