By Andrew Markel
Editor, Brake & Front End Magazine
1. All pads are created equal
of the greatest myths out there is that some customers will not use the
full potential of a brake pad due to their driving style or commute.
This is false, because the one time the customer needs to use the full
potential of the pad, the performance will not be measured in dollars
and cents, but inches and feet.
What standards should your
customers use when selecting replacement brake pads? Try them for
yourself! Set aside some time when the shop is not busy or on a weekend
to try out the brands of brake pads your customers install. Perform at
least four emergency stops from 55 mph to a dead stop back to back. Let
your right foot be the judge.
2. The more lube, the less noise
a set of pads or caliper slides in lubricant, no matter how expensive
they are, will not solve a noise issue for an extended period of time.
Why? Because the excess lubricant can melt or some chemicals can flash
off. The melting lubricant can find its way on to the pads causing a
judder problem and longer stopping distances.
Excessive lube also
can attract debris and dirt. As the lube hardens over time, it turns to
a concrete-like substance that causes slides and calipers to stick. If
excessive lubricant finds its way onto the caliper piston’s boot, the
lubricant will attract metal particles that can destroy the rubber.
need only a small amount of lubricant. Some floating one-piece and
two-piece shims require only a small amount of lubricant between the
surfaces of the shim and pad. There is no need to coat the entire back
of a brake pad with a lubricant.
For the caliper anchor pins, a
silicone-based brake grease should be used. It must be compatible with
all rubber compounds including nitrile, Teflon, nylon and other
For the shims, abutment clips and slides, a
synthetic-based boundary-type lubricant that has a high-solids content
and typically contains a variety of friction-reducing ingredients, such
as molybdenum disulfide (moly or MOS2) and graphite, should be used.
3. Shims are not required
of the greatest mistakes made is not installing shims on a new set of
pads. On new vehicles, the shims are designed along with the caliper
and pads. Shims are not a last minute “add-on” to make sure the pads
fit. Instead, they are a critical part making sure the brakes operate
sufficiently and quietly.
More and more OEMs and aftermarket brake
pad manufacturers are using single and two-piece shims that clip on to
the front in-board and outboard pads. This design creates a “boundary
layer,” preventing vibrations from being transmitted to the caliper
and knuckle. They can also prevent heat from being transmitted to the
piston. Shims should always be replaced.
4. All rotors are the same
rotor can fit on a vehicle and still not be the right rotor for the
vehicle or driver. The wrong rotor that fits may develop runout, BTV
and DTV sooner than a quality rotor. Also, low-quality rotors may have
compromises in the structure and metallurgy that may make sense to the
wallet, but not the driver.
5. New rotors need to be machined
rotors are supposed to be finished to specifications and ready to
install out of the box. There should be no reason to give them a “clean
up” cut. If they do need a cut, you need to find a different rotor
A recent Babcox survey found that 35 percent of our
readers are still machining brand new rotors before they install the
rotors on their customers’ vehicles. Machining new rotors shortens
rotor life. It may also leave a rougher finish on the rotors than the
The manufacturing tolerances on most new rotors
average about 0.001 inches or less, with a maximum upper limit of 0.004
inches. Some cars are unusually sensitive to rotor runout. As little as
0.0015 inches of runout on these cars may produce noticeable pedal
6. Repair information isn’t needed for a brake job
brake systems may look the same after a while, but it is the unseen
that can hurt and cause a comeback. It might be as simple as a torque
specification for a caliper bracket or as complex as a disarm procedure
for an ABS system. Technicians need to have access to current repair information. Information can pay for itself by saving time and preventing a comeback.