GMC 4000 Series Service Manual page 290

1 Suction Tube and
Screen Assy.
2 Bracket Bolt
(20-25 ft.-lbs.)
3 Flange Bolts and Lock
Washers
4 Gaskets
Figure 3 9 — Oil Pum p Installation on Engine
without Hydraulic Governor
from oil pan attaching bolts and drain plug.
2. Drain oil from oil pan.
3. Remove oil pan bolts and stud nut, then re­
move oil pan. Scrape off any portions of gasket
which adhere to oil pan flange or to bolting flange
on cylinder block and engine front cover.
OIL PAN INSTALLATION
1. Use gasket cement to hold new oil pan gas­
ket in place at cylinder block and front cover.
2. Position oil pan at engine and install at­
taching bolts and stud nut.
NOTE: Three of the oil pan bolts are longer
than the others; and these must be installed at rear
of oil pan at reinforcement. These bolts may be
readily identified by internal-external type lock
washers. Other pan bolts are shorter.
3. Install drain plug with new gasket, then fill
crankcase with engine oil to "FULL" mark on dip
stick.
OIL PUMP REPLACEMENT
REMOVAL
1. Remove engine oil pan as previously di­
rected under "Engine Oil Pan Replacement."
G M C S E R V I C E M A N U A L
5 Cylinder Block
6 Pump Drive Shaft
7 Pump to Block Bolts
(30-35 ft.-lbs.)
8 Oil Pump
9 Bracket
10 Oil Pan
-2460-2
t
1 Oil Inlet Tube and
Screen
2 Governor Oil Line
Assembly
3 Elbow
4 Flange Bolts
5 Gaskets
6 Pump Mounting Bolts
Figure 4 0 — Oil Pum p Installation on
Engine with Hydraulic Type Governor
2. On engines (351M) with hydraulic type gov­
ernor (fig. 40), remove governor oil line assembly.
3. Remove two special pump mounting bolts,
then remove engine oil pump with oil inlet tube
and screen assembly attached. Oil pump drive
shaft will usually remain in socket in oil pump
shaft.
INSPECTION AND REPLACEMENT
OF SUCTION TUBE AND SCREEN
Inspect screen and tube for damage. If screen
is clogged, the assembly should be removed from
pump and thoroughly cleaned; or a new suction tube
and screen assembly installed.
When installing tube and screen assembly on
oil pump, use new gasket between tube flange and
pump body. Install all attaching bolts loosely, then
tighten bracket bolt first. Correct torque is 20 to
25 foot-pounds. Finally, tighten tube flange bolts.
Figure 39 shows engine oil pump without hydraulic
governor spinner valve.
Sec. 6A
Page 279
GASOLINE ENGINES
7 Oil Pump Assembly
8 Governor Spinner
Valve
9 Bracket
(Welded to Item 1)
10 Spinner Cover Bolt
and Lock Washer