Chevrolet 70 1969 Series, Shop Manual

Page: 690 / 913

E N G IN E 6-19
Figure 3 0 — Sectional V ie w o f O il P u m p a n d G o v e rn o r Sp in n e r V a lv e A s ­
se m b ly
1. Shaft and Inner
Rotor Assembly
2. Puinp Outlet
3. Pump Body
4. Governor Spinner
Shaft
5. Governor Spinner
Vaive
6. Governor Spinner
Cover
7. Governor Pressure
Outlet
8. Shaft Thrust
Washer
9. Valve Spring
10. Valve Adjusting Nut
1 1. Rotor Cover and
Spinner Housing
12. Drive Coupling
13. Outer Rotor
14. inner Rotor
15. Oil Pump Pressure
Relief Valve Spring
Cap
crankshaft front oil seal assembly without removing en ­
gine front cover. Use suitable tool to remove old seal
from Iront cover.
1. [f the front cover is off the engine, coat oil seal outer
surface with scaler, then drive new seal squarely into
cover with the oil seal lip pointing toward inner side
of cover.
2. When the front cover is not removed from engine, use
oil seal installer (J-7879-10) with pulley installer tool
as shown in Figure 27 to press front cover oil seal as­
sembly into place in cover. Seal lip must point toward
inner side of cover and seal should be pressed in until
tool flange contacts surface of cover.
When using installer, the key must be installed in
crankshaft and crankshaft must be turned as necessary to
locate key at top as shown. Seal must not protrude
beyond inner face of cover.
ENGINE OIL PUMP AND
GOVERNOR SPINNER VALVE
The engine oil pum p on all 401 M and 478 M engines,
incorporates a spinner valve assembly which controls hy­
draulic pressure used to operate the engine governor at
carburetor.
OVERHAULING OIL PUMP
(ENGINES WITHOUT HYDRAULIC GOVERNOR)
Key numbers in text refer to Figure 28.
Disassembly
1. Remove four cover bolts and remove cover (8) from
pum p body (10).
2. Remove inner rotor and shaft assembly (6) from
body, and remove outer rotor (7).
3. Remove relief valve spring cap assembly (4) from
pum p body, then remove spring (3) and valve (2).
Cleaning and Inspection (Fig. 28)
1. Wash parts of oil pum p in cleaning solvent. Be sure
screen and suction pipe assembly is clean.
2. Inspect ends of drive shaft (1) which engage distribu­
tor and oil pum p shafts. Replace drive shaft if excess­
ively worn or damaged.
3. Check fit of inner rotor shaft in body (10). If exces­
sive wear is indicated at either the shaft or body, re­
place worn parts.
4. Place the outer rotor (7) in body (10) and insert inner
rotor and shaft assembly in operating position. Check
clearance between outer rotor and body and clearance
between edge of inner rotor lobe and outer rotor with
feeler gauge (fig. 29). If clearances are greater than
specified in “ Specifications” at end of this section, re­
place parts as necessary. Inner rotor and shaft are
furnished for service as an assembly. W'ith rotors in
pum p body, place straight-edge across rotors and
body, then with feeler gauge measure clearance be­
tween rotors and straightedge (fig. 29). Clearance
should be 0.0011 to 0.0064 inch.
5. Use straightedge to check rotor side of pum p cover
for flatness. Also look for grooves and other evidence
of wear on pum p cover. Replace cover if not in good
condition.
6. Inspect relief valve (2) and valve spring (3). Spring
should have 14.7 to 16.3 pounds pressure when co m ­
pressed to 1.69 inches. Spring free length should be
2.72 inches.
Assembling Oil Pump
Refer to Figure 28 for identification of parts.
1. Place relief valve and spring (2 and 3), in pum p body
(10), then install spring cap (4).
2. Install inner rotor and shaft assembly (6), then install
outer rotor (7) in body.
3. Install cover (8) on pump and retain with four cover
CHEVROLET SERIES 70-80 H EAVY D U TY TRUCK SH O P M A N U A L