Chevrolet 10 Series 1970, Service Manual

Page: 380 / 671

ENGINE FUEL 6M -16
F ig . 3 p - l n s t a lI in g V 8 E n g in e F u e l Pump
pump push rod up w hile in stallin g fuel pump
(fig . 3P).
3. Connect fuel pipes to pump. On “ P ” M odels connect
vacuum lin es to pump.
4. Start engine and check fo r leaks.
FUEL A N D V A C U U M PUMP UNIT
Disassembly
1. Scratch locating m arks on fuel co v e r and pump body
so that in lets and outlets w ill be p ro p e rly located
when pump is reassem b led .
2. R em ove bolt and lockw ash er holding down pulsator
c o v e r on fuel side o f pump. Rem ove pulsator c o v e r
and pulsator diaphragm .
3. R em ove screw s and w ashers holding fuel c o v e r to
pump body and rem ove c o v e r.
4. P la c e pump ro ck er arm in soft jawed v is e so that
vacuum side is up and rem ove a ll vacuum co v e r
screw s except any t w o that are d ia m e tric a lly
opposite.
F ig . 4p —Rem oving V acuum D iaphragm
5. P r e s s down fir m ly on vacuum c o v e r to hold heavy
vacuum diaphragm spring com pressed and rem ove
rem aining two screw s. R elea se vacuum c o v e r slow ly
and rem ove c o v e r assem bly, diaphragm spring and
spring retain er.
NOTE:
If d esired , two 10-32NF 1-1/2" screw s
may be screw ed d ia m e tric a lly opposite into
c o v e r to aid in r e lie v in g diaphragm spring
p ressu re when rem ovin g c o ver.
6. L ift vacuum diaphragm and rem ove vacuum valve
fro m body under diaphragm at ro c k e r arm side.
7. Unhook vacuum diaphragm pull rod fro m vacuum
link. This can best be done by extending vacuum
diaphragm and tiltin g tow ards ro ck er arm while r o l l ­
ing pull rod o ff link (fig . 4P).
8. Rem ove pump fro m v is e , in vert pump so fuel side is
up, and rein sta ll ro c k e r arm in v is e . Have pump
body flush with jaw o f v is e .
9. Use a 3/8" o r sligh tly la r g e r d r ill o r a file to r e ­
m ove portion o f ro c k e r arm pin which is upset o v e r
pin washer.
10. D rive out ro ck er arm pin using a long tapered drift.
11. R em ove ro c k e r arm , ro ck er arm spring, spacer
w ashers, fuel and vacuum links, link spacer and
ro ck er arm bushing fro m pump.
12. Rem ove fuel diaphragm.
13. R em ove m etal around diaphragm pull rod seals,
which was displaced by staking, with ch isel, sm all
round file o r sm all grinding wheel. P u ll seals out of
body with hook shaped tool, using ca re not to damage
seal seats.
14. Rem ove a ll va lv e s in fuel and vacuum c o v e rs in the
same manner.
Cleaning and Inspection
1. Clean and rin se a ll m etal parts in solvent. Blow out
all passages with a ir hose.
2. Inspect pump body, fuel c o ver, and vacuum c o v e r fo r
cracks, breakage and distorted flan ges. Examine a ll
screw holes fo r stripped o r cro ssed threads. If any
o f these three parts a re damaged o r i f p ressed in
vacuum pipes in vacuum c o v e r a re bent o r loose the
pump should be replaced.
3. Inspect ro ck er arm fo r w ear o r scorin g at cam shaft
pad, at point o f contact with links and at pivot hole.
Inspect bushing fo r w ear.
Assem bly
1. Install seals by placing seal and reta in er in pull rod
re c e s s o f pump body with rubber end down toward
links and p re s s down fir m ly with fla t end o f 7/8"
d iam eter round bar.
2. Stake die cast lip in four p la ces to retain seals.
3. A ssem b le link sp acer o v e r fuel link.
4. P la ce one vacuum link on each side o f fuel link. The
hook ends o f vacuum link should com e together so
that they surround fuel link. A ll link hooks should
point in sam e direction .
5. P la c e assem bly o f links and sp a cer between lobes of
ro ck er arm with one sp acer w asher on outer side o f
each vacuum link.
6. Slide ro ck er arm bushing through hole in ro ck er
arm , spacer w ashers, links and link spacer. P lace
thick washer o v e r both ends of bushing. (See F igu re
5P fo r c o r r e c t placem ent o f a ll parts in ro ck er arm
and link a ssem b ly.)
VACUUM DIAPHRAGM
CHEVROLET TRUCK SERVICE MANUAL