Make sure the vehicle is cooled down - If you have
recently driven, you may be working with extremely hot pads, calipers
and rotors. Be sure that these parts are safe to touch before moving
on.
Loosen the lug nuts on the wheels -
Using a lug wrench, (one is usually provided along with the car's jack,)
loosen each of the lug nuts that hold the wheels onto the car about two
thirds of the way.
- Jack the car up - Locate
a safe place to position the car jack under your car. Check the
user's manual or check for markings that indicate where to place the
jack. Put some chocks behind the wheels that are on the ground to stop
the car from rolling forward or back. Carefully jack the car up until
the wheel can be removed easily. Place a jack stand or blocks under the
frame of the vehicle. Dont trust the jack alone. Repeat for the other
side of the car so that both sides are securely supported.
- Remove the wheels -
Finish loosening and remove the nuts. Pull the wheel straight
out towards you to remove it.
- If the wheel rims are
Alloy and are either seized or partially seized on the studs, try
kicking the tyre at the bottom with your foot a few times and hopefully
it will move. when this occurs, you should clean the studs, stud
holes, Rotor mounting surface, and the rear mounting surface of the
alloy wheel - with a wire brush and apply anti seize compound before
refitting the wheel.
- You should now be
looking at the rotor (a large, flat metal disc) and the caliper (a large
clamp-like device wrapped around the top of the rotor).
- Remove the caliper bolts
- There are many different ways that the caliper is secured and
different Caliper designs necessitating different removal procedures.
The mounting position also depends on the Caliper design and whether it
is an all one piece, a two piece, or a more complex design Caliper. All
One piece Calipers are generally secured with between 2 to four bolts
at the inside of the stub axle housing. Spray these bolts with WD-40 or to aid in removing them. Using a correct size
Socket or Ring spanner, loosen and remove the bolts MAKING ABSOLUTELY
SURE THAT THERE ARE NO SHIMS FITTED BETWEEN THE CALIPER MOUNTING BOLTS
AND MOUNTING SURFACE. If there are they must be refitted as they were or
the Caliper will not sit correctly.
- If any do fall out
unexpectedly, you will need to refit the Caliper without the brake pads
and using a combination of feeler guages, measure the difference between
the pad mounting surface to the Caliper at the top and Bottom.
Then, work out the difference/s and allocate the shims accordingly.
- Alternatively, many
Japanese vehicles use a 2 piece sliding Caliper that only requires the
removal of 2x forward facing, upper and lower, slider bolts, and NOT the
removal of the entire caliper. These bolts are often 12 or 14mm
heads.
- Additionally, if these
caliper are completely removed, it is much more difficult to fit the
brake pads into them.
- Check the caliper
pressure - The caliper should now move a slight amount if you shake it.
If not the caliper is under pressure and it may fly off when you remove
the bolts. Take extra precaution to not be in its path, whether it is
loose or not.
- Next, have a piece of
light tie wire handy, about a foot long, before you proceed.
- As the caliper will
still be connected to the brake line, hang it up carefully by the wire,
in the wheel well, so that it doesn't drop and have any weight on the
flexible brake hose.
- Remove the top of the
Brake Master cylinder from under the engine hood and inspect the fluid
level before the pistons are 'Squeezed' back to enable the new brake
pads to be fitted. Many mechanics draw some fluid from the master
cylinder before proceding to squeeze the brake Caliper pistons.
- However, a better
method is bleed the old Caliper fluid off by fitting a brake bleeding
hose to the Caliper nipple, place the hose in a small bottle and undo
the bleeder nipple as the pistons are squeezed. They are easily
squeezed with one hand using large 12 inch water pump pliers - much
easier than C or G clamps. So, the pliers are held in one hand and the
bleeder spanner in the other. If it was not intended to bleed the brakes
they still do not need to be, but the old fluid will have been removed
from the Calipers at the same time as squeezing the pistons fully
inwards. Repeat this with the other pad. Note that there is normally
only one piston to be compressed for the right front and likewise for
the left front.
- Remove the pads - Note
how each brake pad is attached. They typically snap or clip in with
attached metal clips. Remove both pads. They may take a little force to
pop out, so take care not to damage the caliper or brake line while
getting them out.
- Put the new pads on -
Spread the special anti seize lubricant that came with your pads, (if
it's not provided you can get it at any auto store,) sparingly on the
metal contact edges and on the back of the pads, the surface of any
shims and the piston pad contact area. This will prevent a lot of
annoying squeaking. Attach the new pads exactly the way the old ones
were attached.
- Check the brake fluid -
Check your vehicle's brake fluid level and add some if necessary.
Replace the brake fluid reservoir cap when finished.
- Replace the caliper -
Slide the caliper slowly back over the rotor, proceeding easily so as
not to damage anything. Replace and tighten the bolts that hold the
caliper in place.
- Put the wheel back on -
Slide the wheel back into place and hand tighten each of the lug nuts
snug.
- Lower the car - With
one side of the car supported by the jack, remove the block or stand on
that side and slowly release the jack and to lower the car. Repeat
for the other side so that both wheels are back on the ground.
- Tighten the lug nuts -
Moving in a "star" pattern, tighten one lug nut, then one across from it
until each nut is fully tightened to torque specification.
- See technical info to
find the torque spec for your vehicle. This will insure the lugs
have been tightened enough to prevent the wheel coming off or
overtightening.
- Start the vehicle -
Making sure the vehicle is in neutral or park, pump the brakes 15 to 20
times to insure proper seating. Push the brake pedal and put the
vehicle in gear if it rolls more than a foot put the vehicle into park.
- Test your new brake
pads and installation - Going no more than 5 MPH on a quiet residential
street, brake like normal. If the vehicle seems to stopping
normally, repeat the test and go up to 10 MPH. Repeat several more
times, gradually going up to 35 or 40 MPH. You can also go 5 MPH in
reverse and brake. These braking tests ensure there are no issues with
your brake-pad installation, gives you confidence when driving on main
streets and helps "seat" the brake pads into place.
- Listen for problems -
When testing, if you should hear a grinding sound such as metal on
metal, you probably have the brake pads reversed (i.e., the inside
surface incorrectly facing out). This should be corrected immediately.
Note that the new brake pads may squeak a little bit until they are
completely broken in.
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