Chevrolet 70 1969 Series, Shop Manual

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G ASO LINE ENGINES 6A-2
T H R O W -A W A Y TYPE REPLACEABLE ELEMENT TYPE
T-3 4 56
Figure 2— Engine Oil Filters
valve rocker arm cover.
When replenishing oil supply in crankcase, add
oil of same brand and quality as is used when
changing oil.
Refer to L U B R IC A T IO N (SEC. 0) in this manual
for recommendations pertaining to oil change in­
tervals and oil filter replacement intervals.
R E P L A C IN G EN G IN E O IL F IL T E R (Fig. 2)
All engines have replaceable element type
filter.
TUNE-UP CHECKS
GASOLINE ENGINE TUNE-UP
OPERATIONS
SPARK P L U G R E M O V A L
1. Clean all foreign matter away from around
spark plugs and wiring using compressed air. Dis­
connect spark plug wires, and loosen each spark
plug one turn.
2. Reconnect plug wires, start engine and
accelerate to approximately 1000 rpm. This is
done to blow away loose dirt particles and carbon.
Failure to do this increases the possibility of for­
eign material lodging under valves, with resultant
false readings and possible valve damage.
3. Stop engine, disconnect plug wires and re­
move spark plugs and gaskets.
C Y L I N D E R C O M PR ESSION T E S T
1. With carburetor choke and throttle in wide-
open position, operate starter with remote control
switch.
C A U T IO N : When using remote switch to oper­
ate starter, the primary wire must be disconnected
R E P L A C IN G O IL F IL T E R E L E M E N T
N O T E : When replacing the throw-away type
engine oil filter used on some engines, a special
wrench (J-22775) is available fo r use either
with a slide-through handle, or with conventional
socket handle, or torque wrench.
1. If filter housing has drain plug, remove
plug and allow oil to drain from housing. Use
wrench to loosen filter housing bolt, then remove
bolt, housing, and filter element as an assembly.
Remove housing gasket.
2. Remove element from housing and discard
element. Clean housing thoroughly. Also clean fil­
ter bracket.
N O T E : When installing the standard oil fil­
ter (PF-7) assembly, coat gasket with engine oil
and torque to 10 to 15 foot-pounds. If heavy duty
filter (PF-29) is used the correct torque for in­
stallation is 20 to 25 foot-pounds.
3. Install new element in housing shell and
position new gasket at filter bracket. Fill the fil­
ter with engine oil, then install shell and element
assembly. Tighten the filter shell center bolt to
45 foot-pounds torque.
4. Start engine and inspect for oil leaks. If
necessary, add oil to raise oil level to " F U L L "
mark on dip stick.
AND ADJUSTMENTS
from coil negative terminal and ignition switch
must be turned on. Failure to do this will result
in damaged grounding circuit in ignition switch.
2. Starting with compression gauge at zero,
crank engine through at least four compression
strokes to obtain highest possible reading.
3. Make compression check at each cylinder
and record each reading.
4. If some cylinders have low compression,
inject about one tablespoon of engine oil into com­
bustion chamber through spark plug hole. Crank
engine to spread oil on cylinder walls, then re­
check compression with gauge.
a. If compression is higher but does not nec­
essarily reach normal pressure, worn piston rings
are indicated.
b. ll compression is not improved by adding
oil to cylinder, it is probable that valves are not
properly seating possibly due to sticking in guides,
or burned valves or seats, or improper valve lash
adjustment.
c. If two adjacent cylinders have lower than
normal compression, and injecting oil into cylin­
ders does not increase compression, the cause
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SHOP M ANUAL