Chevrolet 1977 10 Series, Руководство по ремонту, Страница: 207 / 468

CARBURETOR
6C-13
MODEL M 4 M C / M 4 M E CARBURETOR
DISASSEMBLY
Place carburetor on a holding fixture to prevent damage
to throttle plates (Figs. 6C-34 and 35).
Solenoid (If Equipped)
Remove screws securing the solenoid and bracket to
float bowl and remove solenoid and bracket assembly.
CAUTION:
The solenoid should not be immersed
in any type o f carburetor cleaner and should always
be removed before complete carburetor overhaul.
Air Horn
1. Remove upper choke lever from the end of choke shaft
by removing retaining screw (Fig. 6C-36). Then rotate upper
choke lever to remove choke rod from slot in lever.
2. Remove choke rod from lower lever inside the float
bowl casting by holding lower lever outw ard with small
screwdriver and twisting rod counterclockwise.
3. Remove secondary metering rods by removing the
small screw in the top of the metering rod hanger. Lift
upw ard on metering rod hanger until the secondary metering
rods are completely out of the air horn. M etering rods may
be disassembled from the hanger by rotating ends out of the
holes in the end of the hanger. (Fig. 6C-37).
4. Using special tool J-25322, drive small roll pin (pum p
lever pivot pin) inward just enough until pum p lever can be
removed from air horn. Then remove pum p lever from pump
rod (Fig. 6C-38).
CAUTION:
Use care in removing small roll pin to
prevent damage to pum p lever casting bosses in air
horn.
5. Remove nine air horn to bowl attaching screws; two
attaching screws are located next to the venturi. (Two long
screws, five short screws, and two countersunk screws). (Fig.
6C-39).
6. Remove air horn from float bowl by lifting straight
up. The air horn gasket should remain on the float bowl for
removal later (Fig. 6C-40).
CAUTION:
When removing air horn from float
bowl, use care to prevent bending the small tubes
protruding from the air horn. These tubes are
permanently pressed into the air horn casting. DO
N O T REMOVE.
Air Horn Disassembly
Remove front vacuum break bracket attaching screws.
The diaphragm assembly may now be removed from the air
valve dashpot rod and the dashpot rod from the air valve
lever (Fig. 6C-41).
CAUTION:
Do not place vacuum break assembly
in carburetor cleaner.
F urther disassembly of the air horn is not required for
cleaning purposes. If part replacement is required, proceed
as follows:
1. Remove staking on two choke valve attaching screws,
then remove choke valve and shaft from air horn.
2. A ir valves and air valve shaft should not be removed.
3. If it is necessary to replace the air valve closing spring
or center plastic eccentric cam, a repair kit is available.
Instructions for assembly are included in the repair kit.
Float Bowl
1. Remove air horn gasket by lifting out of dowel
locating pins and lifting tab of gasket from beneath the power
piston hanger, being careful not to distort springs holding the
main metering rods (Fig. 6C-42).
2. Remove pum p plunger from pum p well.
3. Remove pum p return spring from pum p well.
4. Remove power piston and metering rods by
depressing piston stem and allowing it to snap free (Fig. 6C-
43).
The power piston can be easily removed by pressing the
piston down and releasing it with a snap. This will cause the
power piston spring to snap the piston up against the retainer.
This procedure may have to be repeated several times.
Fig. 6C-34~M odel M 4M C Carburetor
Fig. 6C-35--M odel M 4M E C arburetor