Here's the testing and explanation on the low brake pedal:
(1) If complaint involved low brake pedal, pump
pedal and note if it comes back up to normal height.
(2) Check brake pedal response with transmission
in Neutral and engine running. Pedal should remain
firm under constant foot pressure.
(3) During road test, make normal and firm brake
stops in 25-40 mph range. Note faulty brake operation
such as low pedal, hard pedal, fade, pedal pulsation,
pull, grab, drag, noise, etc.
PEDAL FALLS AWAY
A brake pedal that falls away under steady foot
pressure is generally the result of a system leak. The
leak point could be at a brake line, fitting, hose, or
caliper/wheel cylinder. Internal leakage in the master
cylinder caused by worn or damaged piston cups,
may also be the problem cause.
If leakage is severe, fluid will be evident at or around
the leaking component. However, internal leakage in
the master cylinder may not be physically evident.
If a low pedal is experienced, pump the pedal several
times. If the pedal comes back up, worn lining,
rotors, or drums are the most likely causes.
A spongy pedal is most often caused by air in the
system. However, thin brake drums or substandard
brake lines and hoses can also cause a spongy pedal.
The proper course of action is to bleed the system, or
replace thin drums and suspect quality brake lines
Here's the info on the parking brake:
NOTE: Parking brake adjustment is controlled by a
cable tensioner. Once the tensioner is adjusted at
the factory, it should not require further attention.
However, there are two instances when adjustment
will be required. The first is when a new tensioner,
or cables have been installed. And the second, is
when the tensioner and cables are disconnected for
access to other brake components.
The parking brake switch is in circuit with the red
warning lamp in the dash. The switch will cause the
lamp to illuminate only when the parking brakes are
applied. If the lamp remains on after parking brake
release, the switch or wires are faulty, or cable tensioner
adjustment is incorrect.
In most cases, the actual cause of an improperly
functioning parking brake (too loose/too tight/won’t
hold), can be traced to a parking brake component.
The leading cause of improper parking brake operation,
is excessive clearance between the parking
brake shoes and the shoe braking surface. Excessive
clearance is a result of lining and/or drum wear,
drum surface machined oversize, or inoperative
Excessive parking brake lever travel (sometimes
described as a loose lever or too loose condition), is
the result of worn brake shoes, improper brake shoe
adjustment, or improperly assembled brake parts.
A condition where the parking brakes do not hold,
will most probably be due to a wheel brake component.
Items to look for when diagnosing a parking brake
˛ Rear brake shoe wear.
˛ Drum surface machined oversize.
˛ Front cable not secured to lever.
˛ Rear cable not attached to lever.
˛ Rear cable seized.
˛ Brake shoes reversed.
˛ Parking brake strut not seated in shoes.
˛ Parking brake lever not seated.
˛ Parking brake lever bind.
˛ Adjuster screws seized.
˛ Adjuster screws reversed.
Parking brake adjustment and parts replacement
procedures are described in the Parking Brake section
Which leads to :
PARKING BRAKE CABLE TENSIONER
NOTE: Parking brake adjustment is only necessary
when the tensioner, or a cable has been replaced or
disconnected for service. When adjustment is necessary,
perform the following procedure for proper
parking brake operation.
(1) Raise vehicle.
(2) Back off tensioner adjusting nut to create slack
(3) Remove rear wheel/tire assemblies and remove
(4) Check rear brake shoe adjustment with standard
brake gauge. Excessive shoe-to-drum clearance,
or worn brake components will result in
faulty parking brake adjustment and operation.
(5) Verify that parking brake cables operate freely
and are not binding, or seized. Replace faulty cables,
(6) Reinstall brake drums and wheel/tire assemblies
after brake shoe adjustment is complete.
(7) Lower vehicle enough for access to parking
brake lever. Then fully apply parking brakes. Leave
brakes applied until adjustment is complete.
(8) Raise vehicle and mark tensioner rod 6.5 mm
(1/4 in.) from tensioner bracket (Fig. 59).
(9) Tighten adjusting nut at equalizer until mark
on tensioner rod moves into alignment with tensioner
(10) Lower vehicle until rear wheels are 15-20 cm
(6-8 in.) off shop floor.
(11) Release parking brake lever and verify that
rear wheels rotate freely without drag.
(12) Lower vehicle.
NOTE: Do not loosen/tighten equalizer adjusting
nut for any reason after completing adjustment.
REAR DRUM BRAKE
The rear drum brakes are equipped with a self-adjusting
mechanism. Under normal circumstances, the
only time adjustment is required is when the shoes
are replaced, removed for access to other parts, or
when one or both drums are replaced.
Adjustment can be made with a standard brake
gauge or with adjusting tool. Adjustment is performed
with the complete brake assembly installed
on the backing plate.
If you adjust your rear brakes using the "star" tensioner and it comes loose, it's probably worn springs or the tensioner teeth aren't catching. You'll need a rear brake kit which includes all that.