Brake pads are probably one of the things most people send their vehicles
to the shop for. Either lack of know-how or lack of time. Here is how
to alleviate one of those dilemas.
Tools Required:
Sockets or wrenches
A set of pliers
a regular screwdriver
A tire lug wrench
Disc brake quiet
4" C-clamp or brake caliper piston tool.
Brake cleaner
Details:
Brake pads are always to be replaced in pairs (both fronts, both rears
[if applicable]) Use the lug wrench to brake the lugs free as if you were
changing a tire... just the initial torqe dont take them off yet. This
keeps the wheel from spining. Jack up the vehicle and place jackstands
under it. continue removing the lug nuts until you can take off the tire.
A quick run-down on the braking system.. The circular disc is called the
rotor.. this is clamped upon by the brake pads to stop the car. The pads
are housed inside the caliper and it is the caliper that provides the
hydraulic pressure to stop you by having a piston extend. Natuarlly, the
piston will be further out, the more the pads are worn.
The caliper is held in place usually in 2 mounting points. The caliper
could be mounted with 1)bolts which require a socket or wrench, or 2)it
coud have a special bolt on it that would be either male or female, and
either torx or hex-shaped. Torx, is the 6-pointed star-looking bit that
is sold at all auto parts stores. or 3) Ford uses a special kind of pin
that looks like a pencil but its make of rubber surrounded by metal on
two sides. They just squish down and slide in/out.
Once you get the pins out, pull the caliper off the rotor. the pads may
fall out but no big deal. If not, use the screwdriver to pry them out.
Look at the pads and see how worn they are compared to the new ones. Some
pads are rivited on, some are glued.. either work. With the caliper off,
set the caliper aside. *note* do not let the caliper just hang by the
brake hose.. this will stretch the fibers in the hose and can cause it
to collaps and your brakes will fail. Either set it up where it wont fall,
or zip-tie it up out of the way.
The rotors should always be resurfaced (turned) when doing a brake job...
if the rotors are good and no bad grooves in them, you can get away with
it. but i recommend turning them. (*see below for rotor removal*)
Take the new pads and lay them face down on a clean surface (metal side
up) Use the disc brake quiet (spray is easiest) and lightly coat the backs
of the pads. If the pads come with shims, lay the shims on now and hit
them again with the spray... make sure not to get any on the fronts where
the rotor sits. Wait until they get tacky which should be about a minute...
while waiting, on the caliper,notice the protruding piston. On most pistons
you can just compress the piston and it will go back in.. on the newer
ones you have to spin the pistons to get them to go back in...Unless you
have someone that knows for sure , you can purchase a caliper tool for
about $5 at the auto parts store. If you dont need it, you can return
it. The tool is fairly easy... find the right side of it and put in in
the piston and spin. To compress the piston, use an old brake pad, and
put the C-clamp over the pad and the back of the caliper. Very slowly
tighten the clamp until the piston is flush... If you go two fast, it
will back flood the master cylinder and fluid will spill out. Not really
a problem but brake fluid eats paint and rubber parts so be cautious..
if it comes out, before you take off, just put the master cylinder cap
back on.
Now that you have the caliper back to normal, take out the old pads and
put the new pads in place... notice the pads are curve at the top as is
the caliper.. and one pad may have a metal hinge looking thing on it..
this goes inside the piston. If you forget, you can look at the other
side, but i don't think its possible to put them in wrong and have it
fit. with the pads in, push them in to make sure they stick. then just
put the caliper back on and bolt it up. (or slide the pins in.) There
is no adjustment to be made and the rotors may be stiff but they will
soon get a wear pattern. Do the same for the other side and you are good
to go. Important note, regardless if you spilled some or not, check your
brake Master Cylinder. It is located under the hood on the other side
of where the brake pedal is.. there is a big round disc behind it called
the brake booster.. this uses vacum to assit braking.. the booster is
"power brakes" other wise it would be hard to stop. On the master
cylinder there should be a full line or max and min. make sure you are
good on fluid.. you never want this to run dry. Then you get air in your
lines and its a big mess. Remember about brake fluid and paint!
When putting your wheels back on, tighten them up very well but not put
so much power behind it that you break the lugs (studs). You are now done
with a pad change.
For rotor replacment or resurfacing, the rotors can be either held on
with a nut, or just slide on and off held by the caliper and the wheel.
I cant say for sure when this changed but I believe cars with 4-wheel
disc brakes have the rotors that slide on and off. There may be little
E-clips on each wheel lug that holds it on. just pop these off with a
screwdriver... you'll never use them again. These types of cars have a
hub assembly behind the rotors. What that means is that the spindle to
the rotor has a big bearing that spins.. if this goes out, you replace
the entire thing.. no muss no fuss.
Now, for the older vehicles and still some trucks, the rotor is held on
buy the spindle nut...generally about 1" - 1 1/2", they require
a big socket. Once the nut is off, you can pull the rotor off along with
an inner and outer wheel bearing. this is what these rotors ride on to
spin so fluently. You can either re-use or use new bearings... either
way, you have to re-pack them. You will need some bearing grease found
at the parts store (its also a good idea to get new bearing seals as well).You
can pick up a bearing packer which forces grease through the bearings
or you can put a glob of grease in your hand and using the side of the
bearing, roll it in the grease to fill all the little cracks and crevices
in the bearing. With that done clean your hands as best as possible, install
the bearing seal on the spindle, then the inner bearing, then the rotor,
then the outher bearing making sure that its tight on the outer and inner
bearings... then just install the washer and spindle nut and the cotter
pin and you are set.. use brake clean to clean off any grease or fingerprints..
Now you have changed your brakes and saved money!
