Chevrolet 1977 light duty truck, Руководство по обслуживанию

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fluid. C oat p rim a r y an d secondary seals on secondary
piston w ith clean brake fluid. Insert the secondary piston
spring re ta in e r into secondary piston spring. Place
r e ta in e r an d spring over end o f secondary piston, so that
re ta in e r locates inside lip o f p rim a r y cup.
7. Hold m aster cylinder with open end o f bore
down, push secondary piston into bore, so that spring
will seat against closed end o f bore.
8. Place m aster cylinder in a vise w ith open end o f
bore up. Coat p rim a ry an d secondary seal on p rim ary
piston with clean brake fluid. Push p rim a ry piston
assembly, spring end first, into bore o f m aster cylinder.
Hold the piston down an d snap lock ring into position in
groove in inside d ia m e te r o f bore.
9. Install a new reservoir d ia p h ra g m in reservoir
cover w h ere needed, and install cover on m aster cylinder.
Beaded side faces m aster cylinder casting to insure
positive sealing. The bail wire is now pushed into
position to hold reservoir cover.
10.
M anual brake
only-Assemble push rod through
push rod retainer, if it has been disassembled. Push
re ta in e r over end o f master cylinder. Assemble new boot
over push rod an d press it down over the push rod
retainer.
Installation
C A U T IO N :
Refer to "Caution" on Page 1 o f
this section regarding fasteners referred to in
Steps 1 and 2 below.
1. M an u al brake only-C onnect push rod to brake
pedal pin and install retain er while holding master
cylinder in place.
2. Install m aster cylinder on dash or power
cylinder; torque nuts to specifications.
3. C onnect brake pipes to m aster cylinder.
4. Bleed hydraulic system.
5. R oad test vehicle for p ro p e r brake perform ance.
Bendix Mini-Master Cylinder
N O T E : R em oval, Inspection an d Installation
procedures are the same as described for "Except
Bendix M in i-M a ste r Cylinder".
Disassembly
1. Rem ove the reservoir cover and d ia p h ra g m , and
d r a in the fluid fro m the reservoir.
2. Remove the fo u r bolts that secure the body to
the reservoir using Socket J-25085.
3. Rem ove the small " O " ring and the two
co m p en satin g valve seals from the recessed areas on the
bottom side o f the reservoir.
N O T E : Do not remove the two small filters from
the inside o f the reservoir unless they are da m a g e d
an d are to be replaced.
4. D epress the p rim a ry piston using a tool with a
sm ooth ro u n d ed end. T h e n remove the com pensating
valve poppets an d the com pensating valve springs from
the com pensating valve ports in the m aster cylinder
body.
5. Using a small screwdriver, remove the snap ring
at the end o f the m aster cylinder bore. T hen release the
piston an d remove the p rim a ry and secondary piston
assemblies from the cylinder bore. It m ay be necessary to
plug the front outlet port and to apply low a ir pressure to
the front com pensating valve port to remove the
secondary piston assembly.
Assembly
1. Lubricate the secondary piston assembly and the
master cylinder bore with clean brake fluid.
2. Assemble the secondary spring (shorter o f the
two springs) in the open end o f the secondary piston
actuator, and assemble the piston retu rn spring (longer
spring) on the projection at the rear o f the secondary
piston.
3. Insert the secondary piston assembly, actuator
end first, into the m aster cylinder bore, and press
assembly to the bottom o f the bore.
4. Lubricate the prim ary piston assembly with
clean brake fluid. Insert the p rim a ry piston assembly,
actuator end first, into the bore.
5. Place the snap ring over a smooth round ended
tool and depress the pistons in the bore.
6. Assemble the retaining ring in the groove in the
cylinder bore.
7. Assemble the com pensating valve seals and the
small " O " ring seal in the recesses on the bottom o f the
reservoir. Be sure th at all seals are fully seated.
8. W hile hold ing the pistons depressed, assemble
the com pensating valve springs an d the com pensating
valve poppets in the com pensating valve ports.
9. Holding the pistons compressed, position the
reservoir on the m aster cylinder body and secure with
the four m ounting bolts. Tighten the bolts to 12-15 ft.
lbs.
DELCO DISC BRAKE SHOE AND LINING
Lining Inspection
Inspect the brake linings every 7,500 miles and any
time that the wheels are removed (tire rotation, etc.).
Check both ends o f the outboard shoe by looking in at
each end o f the caliper (fig. 5-18). These are the points at
w hich the highest rate o f w ear norm ally occurs. However,
at the same time, check the lining thickness on the
inboard shoe to make sure that it has not worn
prem aturely. Look down through the inspection hole in
the top o f the caliper to view the in b o ard shoe.
W henever the thickness o f any lining is w orn to within
.030" o f rivet at either end o f the shoe, all disc brake
shoe and lining assemblies should be replaced at the
same time (fig. 5-19).
Caliper Removal
W A R N IN G : See " W a rn in g " on Page 5-1
of this section.