Chevrolet 70 1969 Series, Shop Manual

Page: 658 / 913

POWER BRAKE 5-49
lock wires, then press piston pins out of pistons and
connecting rods.
CRANKSHAFT REM OVAL
BELT-DRIVEN TYPE
1. Remove cap screws and lock washers attaching front
end cover to crankcase, then remove front end cover
and end cover gasket. R em ove and discard cover oil
seal.
2. Remove cap screws and lock washers attaching
crankcase rear end cover to crankcase. Remove rear
end cover and gasket.
3. Press crankshaft and front bearing out of crankcase.
NOTE: It may not be necessary to remove
crankshaft bearing if inspection indicates bear­
ing to be in good condition. Check condition of
bearing on crankshaft as directed later under
"Cleaning, Inspection, and Repair.''
4. If bearing is found defective, press front bearing off
crankshaft using arbor press.
GEAR-DRIVEN TYPE (Fig. 8)
1. Remove cotter pin and nut from front end of cran k­
shaft and pull drive hub off shaft. Remove drive hub
key from keyway in shaft.
2. Remove cap screws attaching rear end cover to
crankcase and remove cover and oil seal. Rem ove oil
seal from boss on cover.
NOTE: Crankshaft rear bearing will come off
with end cover.
3. Remove crankshaft through rear end cover opening.
4. Remove crankcase front and rear thrust washers. Do
not remove crankshaft bearings from crankcase and
end cover unless inspection shows necessity for rem ov­
al.
CYLINDER BLOCK REMOVAL
A N D DISASSEMBLY
R e m o v e c a p s c r e w s s e c u r i n g c y l i n d e r b lock to
crankcase, then remove cylinder block and cylinder block
gasket. Discard gasket.
CLEANING, INSPECTION, A N D REPAIR
CLEAN IN G
GENERAL
Thoroughly wash all parts in a suitable cleaning fluid to
remove all traces of dirt, oil, or grease.
AIR STRAINER
Thoroughly clean all air passages with a suitable clean­
ing fluid to remove all traces of dirt, oil, or grease. Install
new paper filter elem ent or polyurethane foam filter ele­
m ent into respective air strainers.
CYLINDER HEAD
Soak cylinder head in cleaning fluid to loosen carbon
from discharge valve cavities and unloading cavity, and to
loosen rust and scale. Blow dirt out of all cavities with
com pressed air. Scrape carbon and dirt from all surfaces.
Scrape gasket particles from gasket surfaces.
DISCHARGE VALVES
Clean discharge valves, if not worn excessively or d a m ­
aged, by lapping with crocus cloth held on a flat surface.
OIL PASSAGES
Thoroughly clean oil passages through crankshaft, con­
necting rods, and crankcase rear end cover. If necessary,
prod oil passages with a piece of wire, then flush passages
with cleaning fluid and blow out with com pressed air.
CYLINDER BLOCK
Soak cylinder block in cleaning fluid to loosen carbon
and dirt from air intake cavity. If water-cooled type, clean
rust and scale from water passages. Blow out all passages
with com pressed air.
PISTONS
Scrape all carbon and dirt out of ring grooves in pis­
tons. Clean drain holes in oil ring grooves.
BALL BEARING
Im m erse bearing in cleaning fluid, then brush off old
lubricant. Blow bearing dry with com pressed air, and
w rap in clean cloth. Avoid spinning bearing with air blast,
as spinning might dam age bearing.
CRAN KCASE AND BOTTOM COVER
O n gear driven compressors, wash crankcase and bot­
tom cover in cleaning fluid. Rem ove all sedim ent from
sum p in bottom of cover.
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SHOP M A N U A L