Time for a ‘mourning’ break?
When you are
driving your old LaSalle or Cadillac down the road and you need to apply
brakes, either for a regular or panic stop, you have the right to expect a
smooth, even stop.
How quickly you stop should depend
on how hard you push the brake pedal. When this doesn’t happen, you experience the same effect as a triple dose of milk of
magnesia — only quicker.
Hopefully, since last month you have
rebuilt your brakes or have determined that your braking system is in good
condition and only needs adjusting. If you have installed new brake shoes
and/or turned the drums, you should readjust them after a couple hundred miles
and they are “broken in.”
The
adjusting of new brakes or older brakes is basically the same procedure, with a
few exceptions. A few minor details we will cover as we go along. Let’s also
assume you are going to do it right.
Start
out by jacking up all four wheels and put the car on stands. If you have new
brakes, everything should be clean…otherwise the first thing to do is a
thorough cleaning.
Let’s get started—it will be much
easier if you remove all four wheels, but not the drums (this is a good time to
rotate your tires, too.)
Start off by either disconnecting
your emergency brake cable at the “Y” under
the center of the car, or at least loosening it to where each rear cable is
loose and sagging. At this time, squirt a little penetrating oil where the
cable goes into the sheath where it connects to the rear frame near each rear
wheel.
Work
each cable back and forth until it is free and wipe off any excess oil that
could collect dirt. Loosen the adjusting star wheel all the way. Usually this
means an upward movement of the star wheel. This will make removal of the drum
much easier.
Now take off, starting at the right
rear. Take off the drum and start cleaning, first with compressed air blowing
away all brake dust. You should wear a filter mask when doing this, as some
older shoes were made of asbestos.
Next,
you will want a couple of cans of “brake and electric cleaner” on hand and wash
down all components thoroughly, including the inside of the drum and the faces
of the brake shoes. Wipe down and blow off with compressed air. Inspect all
parts.
If the shoes are worn down and/or
you have grooves in the drum, it is time to go to last month’s article and
rebuild the brakes. It is not uncommon to find that the front brakes have been
relined three times and the rears have never been relined. There are two
reasons for this: First, the front brakes wear out three times quicker than the
rear ones and the rear drums are five times harder to get off (usually).
If
you do have to reline one rear brake, always do both sides. The same applies to
the front, however, not true as far as front to rear. Make sure the emergency
brake mechanism is operating freely; and a little squirt of penetrating oil in
the front of the sheath worked back and forth will help, but make sure all
excess is wiped off.
Any type of oil, grease or brake
fluid on the shoes or drums is real bad news. If there is any sign of brake
fluid in the brake mechanism, you need to replace or rebuild the wheel
cylinder. You might note that if you have axle grease in this assembly, you
should replace the seal (see your shop manual).
The
top anchor pin at the top of the brake shoes is actually an eccentric pin and
is a very important adjustment. It is held in place by a lock nut on the rear
of the backing plate. You will notice this anchor pin is adjustable from the
rear of the backing plate and formed in a manner that indicates the “high
side.”
If
worn off or not visible, mark it with a center punch or white crayon. Then
loosen this locking nut and make sure it can be rotated freely and return it to
the position it was prior to loosening, but do not tighten at this time.
With
the star adjusted all the way down, you are ready to put the drum back on and
tighten the axle nut. The last thing before you put the drum on is to give the
drum and lining a final cleaning with brake cleaner to remove any dirt from
fingers, etc.
Now the wheel should spin
freely. If not, adjust the eccentric
until it does. If it still doesn’t spin free, your linings are too large and
need to be arced down or you didn’t
put it together right.
Back
to the shop manual. Spin the wheel and start turning the star wheel until a
show starts to rub—at this point, you are ready to start adjusting.
If
the drums are on the other three wheels, step on the brake hard a few
times. This should somewhat adjust your eccentric. Spin the wheel again and if
you do not have the lining making contact, repeat the process until it still
rubs slightly.
Now
is the time to get out a .015 feeler gauge. You will find a small slot in the
drum at the outer edge that will let you slide the feeler gauge between the
face of the drum and the lining.
With
the feeler gauge in place, rotate the drum to find the high spot. You can now
adjust the eccentric anchor pin to a point as near as possible, tighten the
lock nut on the anchor pin making sure you hold the adjustment in place with
another wrench so you don’t move this very fine adjustment. Now adjust your
star wheel to a point you have resistance when the feeler gauge is in place and
the wheel turns freely when the gauge is out.
If you are adjusting old brakes, you
should at this time bleed until it is clear and clean. Now you can go to the
left rear wheel and repeat the process.
Doing the front wheels starting with
the right front is basically the same except for the way the drum comes off.
While the front drum is off, it is a good time to pack the wheel bearing. Do
not overdo it. The spindle should only have a thin coating of grease.
The
bearings should be packed with good grease and not the spindle cavity. Tighten
down the spindle nut until you feel resistance and then back off the nut to the
next slot where you can put in the cotter pin. Always use new cotter pins.
Now that all four
brakes are adjusted, you are ready to adjust your emergency brake cables. With
the cable still loose at the “Y”, you should be able to pull the emergency
brake handle all the way up and still turn the rear wheels by hand. Work it a
few times to make sure it is free for full travel. Lube where necessary to have
free travel all the way.
When you have it
operating freely, it is time to adjust. First of all, pull the brake handle two
clicks and while in this position, get under the car and tighten up this
adjustment to a point you start to feel the rear linings come into contact with
the drums.
If your cables are stretched
and you cannot adjust to this point, you may have to get some brake cable
tighteners at your local parts or accessory store. Put your tires and wheels
back on and spin each wheel, making sure you have no drag.
Have someone push the brake pedal slightly
just to the point where you have slight friction; but don’t lock the wheel—make
sure all four wheels are close to the same amount.
You should be ready
to put the car on the ground for a test drive, or more accurately, a brake
test. On your test drive, be sure to “drag” your brakes a bit to set them in.
Don’t overdo it but drive about a block with slight pressure on the brake
pedal. Let them cool down and do it again.
Well now, tomorrow you
can enjoy a jelly doughnut with your morning coffee break, instead of mourning
a bad roll because of a bad brake.
See ya next month.
—Walt