BRAKES 5-23
Fig.
34—Brake Drum Access Hole
2.
Install brake drum, aligning tang with wheel hub
(fig. 18).
3.
Install wheel and tire assembly.
. 4. Make final brake adjustment as outlined in this
section and check brake operation.
BRAKE PIPE DISTRIBUTION AND SWITCH
ASSEMBLY (Fig. 2)
Removal
1.
Disconnect battery cable.
2.
Disconnect electrical lead from switch assembly.
3.
Place dry rags below the switch to absorb any fluid
spilled during removal of switch.
4.
Disconnect four hydraulic lines from connections
at switch. If necessary, loosen line connections at
main cylinder to loosen lines. Cover open line ends
with clean, lint-free material to prevent foreign
matter from entering the system.
5.
Remove mounting screw and remove switch from
vehicle.
Installation
1.
Make sure new switch is clean and free of dust and
lint. If any doubt exists, wash switch in Declene,
or equivalent, and dry with air.
2.
Place switch in position and secure to bracket with
mounting screw.
3.
Remove protective material from open hydraulic
brake lines and connect lines to switch. If necessary,
tighten brake line connections at main cylinder.
4.
Connect switch electrical lead.
5.
Connect battery cable.
6. Bleed the brake systems as outlined in this section.
CAMARO PRESSURE REGULATOR VALVE
(AIR CONDITIONED MODELS ONLY)
Removal (Fig. 3)
1.
Place dry rags below valve to absorb any fluid
spilled during removal of valve.
2.
Disconnect hydraulic brake lines from both sides
of switch. Cover open line ends with clean, lint-free
material to prevent foreign matter from entering
the system.
3.
Remove mounting screw and remove switch from
vehicle.
Installation
1.
Make sure new valve is clean and free of dust and
lint. If any doubt exists, wash valve in Declene, or
equivalent, and dry with air.
2.
Place valve in position and secure to frame side
rail with mounting screw.
3.
Remove protective material from open hydraulic
brake lines and connect lines to each side of valve.
4.
Bleed brake system as outlined in this section.
CHEVROLET CHASSIS SERVICE
BRAKES
5-24
DISC BRAKES
INDEX
Page
General Description
. 5-24
Maintenance
and
Adjustments
5-24
Bleeding Hydraulic System
5-24
Parking Brake Adjustment
-
Corvette
5-24
Component Replacement
and
Repairs
5-25
Page
Brake Shoes
. . . . . 5-25
Brake Caliper
5-26
Brake Disc
5-29
Main Cylinder.
5-30
Parking Brake Shoes
-
Corvette
5-30
GENERAL DESCRIPTION
Four wheel disc brakes
are
standard equipment
on
the
1967
Corvette,
as in 1966. The
Corvette
may
also
be equipped with heavy duty disc brakes which include
new front calipers, shoes, linings,
and
rear pressure
regulator valve. This heavy duty option
is
used
in
conjunction with
a
vacuum power unit. Front wheel disc
brakes
are
installed
as
optional equipment
on
Chevrolet,
Chevelle, Camaro,
and
Chevy
II
models.
The disc brake,
(fig. 35),
consists
of a
fixed caliper,
rotating disc, splash shield,
and
mounting bracket.
The
caliper assembly contains four pistons and two shoe
and
lining assemblies with
the
lining riveted
to the
steel
shoes.
A
seal
and
dust boot
are
installed
on
each piston,
with
a
piston spring
in the
caliper cylinder bore beneath
each piston.
A
retaining pin extends through each caliper
half
and
both shoes
to
hold
the
shoes and linings
in
posi-
tion
in the
caliper.
On
Corvette heavy duty disc brakes,
two retaining cotter pins
are
used
at
each end
of the
caliper
to
secure
the
shoes
and
linings. Machined
sur-
faces within
the
caliper prevent
the
shoe
and
lining
assembly from rotating with
the
brake disc when pres-
sure
is
applied.
The disc, which
has a
series
of air
vent louvers
to
provide cooling,
is
mounted
on the
front wheel-hub.
The caliper straddles
the
disc and mounts
on a
mounting
bracket attached
to the
steering knuckle with
two
bolts.
The Corvette heavy duty option includes
a
pressure
regulator valve mounted
in the
rear brake line just
below
the
main cylinder. Chevrolet, Chevelle, Camaro,
and Chevy
n
models with disc brakes have
a
pressure
regulator valve mounted
in the
front brake line just
below
the
main cylinder. The valve controls
the
hydraulic
pressure
to the
front
or
rear brakes,
as
applicable,
resulting,
in the
correct pressure balance between
the
front
and
rear hydraulic systems. This valve guards
against premature .lock-up
of
front
or
rear wheels when
brakes
are
applied.
Maintenance, adjustment,
and
service operations which
are
not
included
in
this section
are the
same
as for
the Duo-Servo type brakes.
MAINTENANCE
AND
ADJUSTMENTS
BLEEDING HYDRAULIC SYSTEM
The operation
of
bleeding
the
disc brake hydraulic
system
is the
same
as for
Duo-Servo system outlined
in
the
front
of
this section. Note
the
exceptions below
and refer
to
bleeding procedures under Duo-Servo
brakes.
1.
When pressure bleeding equipment
is
used,
the
correct pressure setting
for
bleeding disc brakes
is 10-2.0
lbs. on
Corvette,
and 40 lbs. on all
other
models.
2.
The
front calipers contain
one
bleeder valve.
The
rear calipers
on
Corvette contain two bleeder valves
(one inboard
and one
outboard) which necessitates
the removal
of the
rear wheels
for
bleeding.
3.
Tapping
the
caliper with
a
rawhide mallet
as the
fluid
is
flowing
out may
assist
in
obtaining
a
good
bleeding
job.
4.
On
Chevrolet, Chevelle, Camaro
and
Chevy
II, the
spring loaded
end of the
pressure regulator valve
(fig.
36)
must
be
held (valve
in
open position) while
bleeding. This
is
done
by
depressing
and
holding
in
the
plunger
in the
end
of
the valve either
by
hand,
by taping,
or by
clamping.
PARKING BRAKE-CORVETTE
Adjustment
1.
Raise rear
end of
vehicle
and
place
on
jack stands.
2.
Remove rear wheels.
3/
Loosen brake cables
at the
equalizer until
the
park-
ing brake levers move freely
to the "off"
position
with slack
in the
cables.
4.
Turn
the
disc until
the
adjusting screw can
be
seen
through
the
hole
in the
disc.
5. Insert
an
adjusting tool
or
screw driver through
the
hole
in the
disc
and
tighten
the
adjusting screw
by
moving your hand away from
the
floor
on
both
the
left and right sides
(fig. 37).
6. Tighten until
the
disc will
not
move, then back
off
ten
(10)
notches.
7. Apply
the
parking brake four
(4)
notches from inside
the
car.
8. Tighten
the
brake cables
at the
equalizer
to
produce
a light drag with
the
wheels mounted.
9. Fully release
the
parking brake handle
and
rotate
the rear wheels.
No
drag should be evident with
the
handle released.
CHEVROLET CHASSIS SERVICE MANUAL
BRAKES 5-25
CORVETTE
CHEVELLE-CAMARO-CHEVY II
Fig.
35-Disc Brake-Cutaway View
COMPONENT REPLACEMENT AND REPAIRS
BRAKE SHOES
Shoes 'with bonded linings should be replaced when the
groove in the center of the lining is worn off leaving
approximately 1/16 inch of lining thickness. Shoes with
linings retained by rivets should be replaced when the
lining is worn to approximately .020" thickness over
the rivet heads.
Removal
1.
Siphon 2/3 of the brake fluid from the main cylinder
reservoirs.
CAUTION: If fluid is not removed, insertion
of the new full thickness lining will force the
pistons back into the housing displacing fluid •••
into the master cylinder. This will cause fee
main cylinder to overflow,, Do not drain the
reservoirs completely or air will be pumped
into the system. ~
2.
Raise vehicle and place on jackstands.
3..
Remove wheels.
4.
Remove and discard the cotter pin from the inboard
end of the shoe retaining pin and slide out the re-
taining pin. On Corvette with heavy duty disc brakes,
two retaining pins must be removed, one on each
end of the caliper assembly.
5. Remove the inboard shoe by rotating either end of
shoe out of caliper and pulling shoe out.
6. Insert new shoe with lining into position. Use a
putty knife to push each piston back as the shoe is
inserted as shown in Figure 38.
7. Replace the outboard shoe as described above. When
both caliper shoes have been replaced, install the
shoe retaining pin through outboard caliper
half,
outboard shoe, inboard shoe, and inboard caliper
half.
Insert a new 3/32 x 5/8 plated cotter pin
through the retaining pin and bend back ends of
cotter pin. (On Corvette heavy duty front caliper,
CHEVROLET CHASSIS SERVICE
BRAKES 5-26
PRESSURE
REGULATOR
VALVE
CHEVROLET
PRESSURE
REGULATOR
VALVE
CAMARO
Fig.
36—Pressure Regulator Valve—Chevrolet and Camaro Shown
install two retaining cotter pins, one at each end of
the caliper.)
8. Repeat above procedure at each wheel where shoes
are to be replaced.
9. Refill main cylinder to fluid level shown in Figure
8. If necessary, bleed brake system as outlined in
this section.
10.
Install wheels and lower vehicle.
BRAKE
CALIPER
Removal
1.
Raise vehicle and place on jackstands.
2.
Remove wheel.
3.
On front caliper, disconnect the brake hose at brake
line support bracket. On Corvette rear caliper,
disconnect the brake tubing from the inboard caliper.
Tape the open tube or line end to prevent foreign
matter from entering the system.
4.
Pull cotter pin from end of shoe assembly retaining
pin.
Remove the pin and shoe assembly from the
Fig.
37—Adjusting Parking Brake Shoes
Fig.
38—Replacing Shoe and Lining Assembly
CHEVROLET CHASSIS SERVICE MANUAL
BRAKES 5-27
CHEVELLE
, CHEVY II AND CAMARO SHOWN
1.
Caliper Belts
2.
Bleeder Valve
3. Caliper Half
4.
Piston Spring
Fig.
39-Caliper Assembly-Exploded View
5. Seal
6. Piston
7. Piston Boot
8. Brake Shoes
9. "O" Ri
10.
Caliper
11.
Retaining Pin
12.
Cotter Pin
caliper. Two retaining pins must be removed on
heavy duty Corvette front calipers. Identify the
inboard and outboard shoe if they are to be reused.
5. Remove the end of brake hose at bracket by re-
moving U-shaped retainer from the hose fitting and
withdrawing the hose from bracket.
6. Remove the caliper assembly from the mounting
bracket by removing two hex head bolts.
Disassembly (Fig. 39)
1.
Clean exterior of caliper with Declene, or equivalent.
On Chevrolet and Corvette front caliper, remove
brake hose.
2.
Separate the caliper halves by removing the two
large hex head bolts. Remove the two small "O"
rings from the cavities around the fluid transfer
holes in the two ends of the caliper halves.
3.
To free the piston boots so that the pistons may be
removed, push the piston down into the caliper
as far as it will go. Insert a screwdriver blade
under the inner edge of the steel ring in the boot,
and using the piston as a fulcrum, pry the boot from
its seat in the caliper
half.
CAUTION: Use care not to puncture seal when
removing pistons from caliper. ' ~
4.
Remove the pistons and piston springs from the
caliper
half.
Remove the boot and seal from their
grooves in the piston.
Cleaning and Inspection
1.
Clean all metal parts using Declene, or equivalent.
Remove all traces of dirt and grease. Do not use
mineral base solvents to clean brake parts.
2.
Using an air hose, blow out all fluid passages in the
caliper halves, making sure that there is no dirt
or foreign material blocking any of these passages.
3.
Discard all rubber parts. Boots, seals, and "O"
rings should be replaced with new service kit parts.
4.
Carefully inspect the piston bores in the caliper
halves. They must be free of scores and pits. A
scored or otherwise damaged bore will cause leaks
and unsatisfactory brake operation. Replace the
caliper half if either bore is damaged to the extent
that polishing with very fine crocus cloth will not
restore it.
CHEVROLET CHASSIS SERVICE MANUAL
BRAKES 5-28
Fig.
40—Installing Piston in Caliper Bore Using
Tool J-22591
Fig.
41—Installing Boot Seal in Caliper Bore
Using Tool J-22592
5.
Check the fit of the piston in the bore using a feeler
gage.
Clearance should be as follows:
2 1/16 inch Bore .0045 to .010
1 7/8 inch Bore .0045 to .010
1 3/8 inch Bore .0035 to .009
If the bore is not damaged, and the clearance exceeds
either of the upper limits, a new piston will be required.
Assembly
1.
Assemble the seal in the groove in the piston which
is closest to the flat end of the piston. The lip on
the seal must face toward the large end of the
piston. Be sure lips are in the piston groove and do
not extend over the step in the end of the groove.
2.
Place the spring in the bottom of the piston bore.
3.
Lubricate the seal with dean brake fluid.
4.
Install the piston assembly in the bore using appli-
cable piston rign compressor Tool J-22639, 22629
or 22591 as shown in Figure 40. Use care not to
damage the seal lip as piston is pressed past the
edge of the bore. .
5.
Assemble the boot in the groove of the piston closest
to the concave end of the piston. The fold in the boot
must face toward the end of the piston with the seal
on it.
6. Depress the pistons and check that they slide
smoothly into the bore until the end of the piston is
flush with the end of the bore. If not, re check piston
assembly and location of the piston spring and the
seal.
7.
Position applicable boot seal installer Tool J-22592,
J-22628, or J-22638 over the piston and seat the
steel boot retaining ring evenly in the counterbore
as shown in Figure 41. The boot retaining ring must
be flush or below the machined face of the caliper.
Any distortion or uneven seating could allow con-
taminating and corrosive elements to enter the bore.
8. Position the t:O}> rings in the small cavities around
the brake fluid transfer holes in both ends of the
outboard caliper halves. Lubricate the hex head
. bolts with Delco Brake Lube or clip in clean brake
fluid. Fit caliper halves together and secure with
bolts.
Refer to torque specifications in rear of
manual for correct torque valves.
Installation
1.
Carefully mount the assembled caliper over the edge
of the disc. Use a putty knife to depress pistons so
that the caliper can be lowered into position on the
disc (fig. 42). Use care to prevent damage to boots
• on the edge of the disc as the caliper is mounted.
2.
Secure the caliper to the mounting bracket with two
hex head bolts. Refer to torque specifications in
rear of manual for correct torque values.
CAUTION: If replacing old shoe assemblies,
be sure to get the shoes in the same position
from which they were removed. New shoe as-
semblies have an arrow printed on the back,
showing the direction of forward disc rotation.
3.
Install the shoe and lining assemblies as outlined in
this section.
4.
On Chevrolet and Corvette front calipers, place a
new copper gasket on the male end of the front
wheel brake hose. On all models, install brake hose
in the calipers. With the wheels straight ahead,
pass the female end of the brake hose through the
support bracket.
5.
Make sure the tube seat is clean and connect the
break line tube nut to the caliper. Tighten securely.
6. Allowing the hose to seek a normal position, without
twist, insert hex of the hose fitting into the 12-point
hole in the support bracket and secure it in place
with the "V"-shaped retainer. Turn the steering
geometry from lock to lock while observing the hose.
CHEVROLET CHASSIS SERVICE MANUAL
BRAKES
5-31
POWER BRAKES
INDEX
General Description 5-31
Maintenance
and"
Adjustments 5-31
Inspection . ... 5_31
Lubrication 5-31
Bleeding Instructions . . . 5.31
Air Cleaner Service . . . , 5.31
Page
Component Replacement 5-31
Power Brake Cylinder ......* 5-31
Removal . . 5-31
Disassembly and Assembly See Overhaul Manual
Installation . . . . 5-31
GENERAL DESCRIPTION
The Power Brake Unit is a self-contained hydraulic
and vacuum unit, utilizing manifold vacuum and atmos-
phere pressure for its power.
This unit permits the use of a low brake pedal as well
as less pedal effort than is required with the conventional
(nonpower) hydraulic brake system. Only two external
line connections are necessary -
one
a vacuum connection
from manifold to check valve located on front shell; the
other, a hydraulic connection from the main cylinder
outlet directly into the hydraulic system. The unit is
mounted on the engine side of the fire wall and directly
connected to the brake pedal.
MAINTENANCE AND ADJUSTMENTS
INSPECTIONS
1.
Check vacuum line and vacuum line connections as
well as vacuum check valve in front shell of power
unit for possible vacuum loss.
2.
Inspect all hydraulic lines and connections at the
wheel cylinders and main cylinder for possible
hydraulic leaks.
3.
Check brake assemblies for scored drums, grease
or brake fluid on linings, worn or glazed linings,
and make necessary adjustments.
4.
Check brake fluid level in the hydraulic reser-
voirs.
The reservoirs should be filled to the levels
shown in Figure 8.
5. Check for loose mounting bolts at main cylinder and
at power section.
6. Check air cleaner filter in power piston extension
and replace filter if necessary.
7. Check brake pedal for binding and misalignment
between pedal
-and
push rod.
LUBRICATION
The power brake unit is lubricated at assembly and
needs no further lubrication other than maintaining
normal reservoir fluid level. The reservoir should be
filled as described in this section.
BLEEDING INSTRUCTIONS
The power system may be bled manually or with a
pressure bleeder as outlined in this section. Use only
GM
Supreme 11 Brake Fluid or equivalent. Do not use the
power assist while bleeding. The engine should not be
running and the vacuum reserve should be reduced to
zero by applying the brake several times before starting
the bleeding procedure.
AIR CLEANER SERVICE
Servicing of the air cleaner is recommended and the
element replaced when restriction becomes severe
enough to affect power brake response. At any other
time, if cleaning of the filter is felt necessary, it should
be shaken free of dirt or washed in soap and water and
thoroughly dried.
COMPONENT REPLACEMENT
POWER BRAKE CYLINDER
Removal
1.
Remove vacuum hose from vacuum check valve.
2.
Disconnect hydraulic lines at main cylinder.
Disconnect push rod at brake pedal assembly.
Remove nuts and lock washers securing power unit
to fire wall, and remove power unit from engine
compartment.
3.
4.
NOTE:
Chevy
to fire wall.
has a three stud attachment
Repair procedures for the power cylinder are outlined
in the Brake Section of the Overhaul Manual-for service
of the main cylinder refer to applicable portion of
"Standard Brakes" in this manual.
Installation
1.
Mount the power brake assembly in place and install
the attaching nuts and lock washers.
2.
Attach vacuum line to check valve.
3.
Secure hydraulic lines to main cylinder.
4.
Attach push rod to brake pedal assembly, and check
operation of stop light.
5. Bleed brakes as outlined in this section.
CAUTION: After replacing the unit on the vehi-
cle,
start the engine and allow vacuum to build
up before applying the brake.
CHEVROLET CHASSIS SERVICE
SECTION 6K
ENGINE COOLING
INDEX
Page
General Description . . . 6K-1
Maintenance and Adjustments 6K-1
Coolant Level 6K-1
Coolant System Checks 6K-1
Periodic Maintenance 6K-2
Cleaning 6K-2
Reverse Flushing 6K-2
Radiator 6K-2
Page
Cylinder Block and Cylinder Head 6K-2
Hot Water Heater 6K-2
Fan Belt . 6K-2
Adjustment ....". 6K-2
Thermostat . 6K-2
Replacement 6K-2
Water Pump. . . . 6K-3
Removal 6K-3
Installation 6K-3
GENERAL DESCRIPTION
A pressure cooling system is provided for on all
models by a pressure type radiator cap (fig. 1). The
pressure type radiator cap used is designed to hold a
pressure above atmospheric pressure in the cooling
system. Excessive pressure is relieved by a valve within
the cap that opens to radiator overflow.
The water pump is a ball bearing, centrifugal vane
impeller type. It requires no care other than to make
certain the air vent at the top of the housing and the drain
holes in the bottom do not become plugged with dirt or
grease. Removal and installation of the water pump is
covered in this section. For overhaul procedures of the
water pump refer to Section 6K of the Passenger Chassis
Overhaul Manual.
For radiator, refer to Section 13 of this manual For
radiator shroud, refer to Section 11 of this manual.
Fig.
I—Pressure Radiator Cap
MAINTENANCE AND ADJUSTMENTS
Coolant Level
The radiator coolant level should only be checked when
the engine is cool, particularly on cars equipped with air
conditioning. If the radiator cap is removed from a hot
cooling system, serious personal injury may result
The cooling system fluid level should be maintained
one inch below the bottom of the filler neck of the radia-
tor when cooling system is cold, or at the bottom of the
filler neck when the system is warm. It is very impor-
tant that the correct fluid level be maintained. The seal-
ing ability of the radiator cap is affected when the cooling
level is too high.
All passenger car cooling systems are pressurized
with a pressure cap which permits safe engine operation
at cooling temperatures of
up
to 247°F.
When the radiator cap is removed or loosened, the
system pressure drops to atmospheric, and the heat
which had caused water temperature to be higher than
212°F, will be dissipated by conversion of water to
steam. Inasmuch as the steam may form in the engine
water passages, it will blow coolant out of the radiator
upper hose and top tank, necessitating coolant replace-
ment Engine operating temperatures higher than the
normal boiling point of water are in no way objectionable
so long as the coolant level is satisfactory when the
engine is cooL
Upon repeated coolant loss, the pressure radiator cap
and seat should be checked for sealing ability. Also, the
cooling system should be checked for loose hose con-
nections, defective hoses, gasket leaks, etc.
Coolant System Checks
1.
Test for restriction in the radiator, by warming the
engine up and then turning the engine off and feeling
the radiator. The radiator should be hot at the top
and warm at the bottom, with an even temperature
rise from bottom to top. Cold spots in the radiator
indicate clogged sections.
2.
Water pump operation may be checked by running the
engine while squeezing the upper radiator hose. A
pressure surge should be felt Check for a plugged
vent-hole in pump.
NOTE:
A defective head gasket may allow ex-
haust gases to leak into the cooling system.
This is particularly damaging to the cooling
system as the gases combine with the water to
form acids which are particularly harmful to
the radiator and engine.
3.
To check for exhaust leaks into the cooling system,
drain the system until the water level stands just
above the top of the cylinder head, then disconnect
the upper radiator hose and remove the thermostat
and fan belt. Start the engine and quickly accelerate
several times. At the same time note any appreci-
able water rise or the appearance of bubbles which
CHEVROLET CHASSIS SERVICE MANUAL