BRAKE SERVICING
PADS AND ROTORS Issue 13/2017
PART ONE
SHOCK ABSORBER, SUSPENSION, BRAKES, TOWBARS AND WHEEL ALIGNMENT SPECIALISTS
Brake Servicing
Checking The Pads
The areas we are going to explore in this Tech Stop are:
The customer wants a report on the brake pads and you tell him/her they should be good until the next service, how do you know that?
• Brake Pads • Disc Rotors
It is far more professional to give the customer a definitive answer. Using the Pedders Brake Pad Thickness Gauge, you can give a precise answer in millimetres, as it is colour coded, you can show the customer the reason why you are recommending a pad change or why you think they will last to the next service. It has been known that mistakes have been made when a brake check has been performed. The report says all is good, pads are OK. A week later the customer comes back with a brake noise, Why? Because when a car is fitted with floating calipers (which is the majority today), the inside pad is sometimes hard to see, so the technician assumed the inside pad would have the same wear rate as the outside pad, which was really good. This was not the case and the inside pad had greater wear as this is the first reaction pad, it comes into contact with the rotor first and therefore has a tendency to wear quicker. Pull the wheels off and have a good look.
Brake Pads The first thing is safety. Through legislation asbestos was banned in the production of brake friction material, so does this mean we don’t have to worry about it in the work place? NO Warning: There are still some older cars driving around with asbestos contaminated brake friction material. So treat all brake friction material with the utmost of respect and DO NOT use compressed air to de-dust the brakes. Even though there may be no asbestos present, you do not want to breath in the fine dust created by the wearing down of the brake material.
Pedders Brake Pad Thickness Gauge
Straight advice, specialists you understand and...
BRAKE SERVICING
PADS AND ROTORS Issue 13/2017
PART ONE
SHOCK ABSORBER, SUSPENSION, BRAKES, TOWBARS AND WHEEL ALIGNMENT SPECIALISTS
Changing Brake Pads
Process for “Bedding-In” Brake Pads
To remove the brake pads, we first have to remove the caliper.
“Bedding-in” is the process of mating a new pad’s surface onto the surface brake disc rotors. Under a microscope, the surface of the pads and rotors are uneven, with high and low points and varying surface areas (think hills and valleys). Until these parts are mated, only the peaks will be making contact, using the brakes hard without bedding-in the brakes, can run the risk of overheating and carbonising the surface of the pad. A glazed surface will likely develop, followed by unnecessary and annoying brake noise. Poor performance from newly installed brake pads is usually the result of an incorrect bed-in procedure.
Once those bolts are removed, lift the caliper off the brake rotor. It will still be connected to the vehicle via the brake line. This is really important - don’t let the caliper hang by the brake hose. This can cause damage to the line and may lead to brake failure. Instead, secure the caliper to a nearby suspension component using a piece of hanger wire. Make sure that the brake line is slack and not twisted or kinked. Check for fluid leaks, condition of caliper to piston dust seals. If it is a floating caliper inspect, clean and lubricate the slides.
Bedding-in Procedure:
Prior to fitting the new pads, the piston in the caliper has to be pushed back to create clearance for the new pad.
After installing your new set of Pedders Ceramic Brake Pads, follow these simple steps:
The procedure is as follows:
1. Find an open stretch of road that will allow you to safely stop your vehicle multiple times.
• Place a bleed pipe onto the bleed nipple • Clamp the flexible brake hose • Open the bleed nipple
2. Accelerate to 55kph and apply moderate brake pressure to reduce your speed to 10-15kph
• Push the piston back into the caliper
3. Repeat this process 3-4 times, the goal is to warm up your brake pads
• The excess old fluid will now be forced into the container
4. Now increase your speed to 75kph and braking down to 20kph
• When the piston is all the way home, close the bleed nipple
5. Repeat this process 3-4 times
• Remove the bleed hose and container
6. Your bedding in session is now complete. Park the car and allow the brakes to cool for an hour.
• Remove the flexible pipe clamp • Place the new pads into the caliper, including any abutment shims and/or clips • Refit the caliper When all the calipers have been fitted to the vehicle, pump the brake pedal until a “Good” pedal is achieved, top up the master cylinder reservoir with the correct “Dot” brake fluid. (This should be written on the reservoir cap, if unsure check O.E.M. specifications). Replace the wheels and tighten the wheel nuts in the correct sequence and torque, road test the vehicle and “Bed in” the pads.
Straight advice, specialists you understand and...
e faces of a disc brake rotor must be parallel and flat (no ore than .06mm of run out). When the brakes are applied pulsation or vibration may be felt in the brake pedal as the or alternately grabs and slips.
BRAKE SERVICING
Disc Rotors
PADS AND ROTORS
A pulsating brake pedal, which also may be accompanied by a shuddering stop during normal braking, usually means a warped rotor or an out-of-round drum. But it can sometimes be caused by loose wheel verheating can also cause arotors to shaft warp.or loose Overheating bearings, bent axle brake parts. If the vehicle is equipped with ABS, some pedal feedback Issue 13/2017 noise is abuse normal or during panic stops or when braking on wet or slick surfaces. But you should not ay be the result and of severe dragging brakes. experience anyasABS pedal when normally on dry firm surfaces. efects in the rotor casting, such thick andfeedback thin areas canbraking also cause uneven cooling that leads to the rotor
PART ONE
SHOCK ABSORBER, SUSPENSION, BRAKES, TOWBARS arping. Hard spots in the metal due to casting impurities canALIGNMENT be yet another cause. AND WHEEL SPECIALISTS
The faces of a disc brake rotor must be parallel and flat (no more than .06mm of run out). When the brakes are applied ou can sometimes see a warp in a brake rotor by simply looking at it. The If the rotor has tell-tale glazed or rotated. Disc Rotors a pulsation or vibration may be felt in the brake pedal as the difference between minimum and maximum coloured patches on its face, chances are it is warped. Measuring it with dial indicator and checking value on the adial indicator is called lateral run it out. Typical alternately grabsalso andmay slips.be A pulsatingrotor brake pedal, which
flatness with a straight edge will confirm the diagnosis.
hub/disc assembly run out specifications for passenger accompanied by a shuddering stop during normal vehicles are around 0.0020” or 50 micrometers. braking, usually means a warped rotor or an out-of-round easuring this is accomplished using a dial indicator on a fixed rigid drum. But it can sometimes be caused by loose wheel bearings, a bent axle shaft or brake loose brake se, with the tip perpendicular to the disc'sparts. face. IfItthe is typically Overheating can also cause rotors to warp. Overheating vehicle is equipped with ABS, some pedal feedback easured about 1/2" (12 mm) from the outside diameter of and the disc. The may during be thepanic resultstops of or severe orondragging brakes. noise is normal whenabuse braking c is then wet rotated. The difference between and and maximum Defects in the casting,minimum such as thick or slick surfaces. Butrotor you should not experience anythin areas can also cause uneven cooling that leads to the rotor lue on theABS dialpedal indicator is called lateral out. due Typical hub/disc feedback whenspots braking normally on dry firm warping. Hard in run the metal to casting impurities can be yet another cause. panied by a shuddering stop during normal braking, surfaces. sembly run out specifications for passenger vehicles are around 0.0020"
um. But it can sometimes be caused by loose wheel can brake sometimes warp in a brake rotor by simply looking at it. If the rotor has tell-tale glazed or The faces You of a disc rotor see musta be parallel and flat 50 micrometers. e vehicle(no is more equipped with ABS, some pedal feedback discoloured patches on its face, chances are than .06mm of run out). When the brakes are it is warped. Measuring it with a dial indicator and checking it for flatness a straight edge confirm aking onapplied wet or slick surfaces. But you should notthe diagnosis. a pulsation or with vibration may be feltwill in the brake thesurfaces. rotor alternately grabs and slips. mally onpedal dry as firm Measuring this is accomplished using a dial indicator on a fixed rigid
brations from New Rotors: base, with the tip perpendicular to the brake disc's face. It is typically
lat (no measured about 1/2" (12 mm) the outside the disc. The ere have been instances where a customer hasfrom returned to the diameter place ofof repair complaining about a brake applied Vibrations from disc is then rotated. The difference between minimum and maximum New Rotors why? The car has just had new rotors and pads fitted. ldal as vibration, the have been instances where a customer has value on the dial indicator is called lateral run out.There Typical hub/disc
returned to the place of repair complaining about a
assembly outthe specifications fornot passenger are around the 0.0020" e answer is more than likelyrun that new rotor is runningvehicles “true”, technician brake because pedal vibration, why? Thedid car not has clean just had new or 50 micrometers. e two mating surfaces and dirt, grit or grime has been sandwiched between the rotor rotors and pads fitted. and the hub flange.
hen fitting new disc rotors to the vehicle Vibrations ere is a procedure to follow: from New Rotors:
The answer is more than likely that the new rotor is not running “true”, because the technician did not clean the two mating surfaces and dirt, grit or grime has been sandwiched between the rotor and the hub flange.
heating Therethe have been instances where a customer has returned to the place of repair complaining about a brake brakes. • Thoroughly clean mounting surface When fitting new disc rotors to the vehicle there is a pedal vibration, why? Theleads car has just new rotors and pads as can cause uneven that thehad rotor procedure to fitted. follow: ofalso the new rotor Overheating can alsocooling cause rotors to warp.toOverheating ities can be yet another cause. may be the result of severe abuse or dragging brakes. • Thoroughly clean the corresponding • Thoroughly mounting surface of the The answer is more than likely that the new rotor is not running clean “true”,the because the technician did new not clean Defects in the rotor casting, such as thick and thin
rotor two mating surfaces andthat dirt,leads grit or surface oncan thethe hub areas also cause uneven cooling to grime the has been sandwiched between the rotor and the hub flange.
mply looking at it. If the rotor has tell-tale glazed or rotor warping. Hard spots in the metal due to casting new disc rotors to the vehicle it ed. Measuring with a dial indicator and checking impuritiesitWhen can befitting yet another cause. there is a procedure to follow: osis. You can sometimes see a warp in a brake rotor by
• Thoroughly clean the corresponding surface on the hub
simply looking•at it. If the rotorclean has tell-tale glazedsurface or Thoroughly the mounting
patches on its face, chances are it is warped. on a fixeddiscoloured rigid of the new rotor Measuring it with a dial indicator and checking it for e. It is typically Thoroughly clean the corresponding flatness with a•straight edge will confirm the diagnosis. er of the disc. The surface on the hub Measuring this is accomplished using a dial indicator on m and maximum a fixed rigid base, with the tip perpendicular to the brake disc’s face. It is typically measured about 1/2” (12 mm) pical hub/disc from the outside diameter of the disc. The disc is then are around 0.0020"
Dirty Hub Face
Clean Hub Face
Straight advice, specialists you understand and...
ason that rotors become warped, is that the wheel nuts have been tightened incorrectly, in two
BRAKE SERVICING
PADS AND ROTORS
Another reason that rotors become warped, is that the wheel nuts have been tightened incorrectly, in two
in the correct ways: sequence to the correct torque • •
PART ONE
Issue 13/2017 Not in the correct sequence Another reason that rotors become warped, is that the wheel nuts have been tightened incorrectly, in two Not to the correct torque SHOCK ABSORBER, SUSPENSION, BRAKES, TOWBARS
air tools to fasten wheel nuts or studs is extremely bad ways: AND WHEEL ALIGNMENT SPECIALISTS nless a torque tube is also used. The vehicle manual will Not innuts the correct sequence The use of air tools to fasten •wheel or studs is extremely bad e properpractice, patternreason for tightening as is asused. torque rating Another that rotors tube become warped, that the Using the air gun to run the wheel nuts up to contact •well Not to theais correct unless a torque also Thetorque vehicle manual will wheelnuts nuts have beennever tightened incorrectly, in two ways: in the recommended sequence is not an issue. The lts. Wheel should be tightened in a circle. indicate the proper for tightening asto well as a torque rating Another reason that rotorspattern become warped, thatairthe wheel nuts been tightened incorrectly, two The useis of tools fastenhave wheel nuts or studs is extremely badperson doing the job uses the problem arises wheninthe icles are sensitive to the force the bolts apply and • Not in the correct sequence for the bolts. Wheel nuts should never be tightened in a circle. ways: practice, unless a torque tube is alsofull used. The vehicle manual will force of the air gun on each wheel nut in a circular indicate pattern as well and as a torque rating should be done with a are torque wrench. Some vehicles sensitive to the theproper force thefor tightening boltspattern. apply • Not to the correct torque • Not in the correct sequence for the bolts. Wheel nuts should never be tightening should be done with a torque wrench. Some vehicles are sensitive to the force
tightened in a circle.
the bolts5 Wheel applyNutand The• use fasten wheel nuts or studs is Notof to air the tools correcttotorque 4 Wheel Nut Pattern Pattern 6 Wheel Nut Pattern 8 Wheel Nut Pattern tightening air gun toextremely run the bad wheel nutsunless up to inbethe practice, a contact torqueshould tube isdone alsowith a torque wrench. Using air guntomanual tofasten run wheel the to contact The usethe of air tools nuts or nuts studs is extremely bad in the used. The vehicle will wheel indicate the up proper pattern ded sequence is not an issue. The problem arises when the Using the airvehicle gun to manual run the wheel nuts up to contact in the practice, unless a torque tube is also used. The will for tightening as well as a is torque rating for The the bolts. recommended sequence not an issue. problem arisesThewhen thearises when the recommended sequence is not an issue. problem indicate thethe pattern for of tightening as well a torque rating ng the job uses full force the air gun each wheel Wheel nutsproper should never be tightened in aason circle. Some person doingWheel the job theperson full be force ofjobthe air gun on each doing the uses full force of the wheel air gun on each wheel for the bolts. nutsuses should never tightened in a the circle. vehicles are sensitive to the the bolts apply andand Some vehicles are sensitive to force the force the bolts apply cular pattern. nut in a circular pattern. nut in a circular pattern. tightening should be done with awrench. torque wrench. Recommended Sequence for Tightening Wheel Nuts tightening should be done with a torque Using the air gun to run the wheel nuts up to contact in the recommended sequence is not an issue. The problem arises when the person doing the job uses the full force of the air gun on each wheel nut in a circular pattern.
Features
Advantages
Features
Advantages
Pedders own brand, Consumers and trade unique compound formula cannot do a price comparison
Made from the highest grade raw materials
Manufactured to the highest possible standards
Ceramic Technology
Improved performance
Positive moulded and use a scorching process
The pad is placed under pressure whilst undergoing the curing (Heat & Pressure)
Curved slotted brake rotor No gas build up between design the pad and the rotor. Keeps the pad surface clean
These pads are an ideal upgrade or replacement solution
For all types of vehicles
Friction material formula specifically designed for the vehicle
The weight and wheel size is taken into account when friction material is formulated
ShimtechTM Shims, unique manufacturing process bonds titanium alloy to a thick layer of synthetic rubber
Results with the shim interacting directly with both the caliper and backing plate
Friction material is slotted and chamfered
For “Noise Vibration Harshness” control
Geomet coated
Superior anti-corrosive protection
High wear resistance
Longer time between rotor changes
Improved design of ventilation between the two friction surfaces
Improved heat dissipation
All rotors have a final manufacturing process of being “Balanced”
This process provides optimal vibration free operation of the rotors
“The balancing witness mark”
“The balancing witness mark”
“The balancing witness mark”
Straight advice, specialists you understand and... “The balancing witness mark”