Chevrolet 70 1969 Series, Shop Manual

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6V-53 DIESEL ENGINE 6C-16
HIGH LUBRICATING OIL C O N SU M PT IO N -C ont.
OIL CONTROL AT CYLINDER
OIL CONTROL RINGS WORN, BROKEN, OR IMPROPERLY IN STALLED—Replace rings on
piston.
PISTON PIN RETAINER LOOSE—Replace piston retainer and defective parts.
SCORED LINERS, PISTONS, OR OIL RINGS—Remove and replace defective parts.
PISTON AND ROD ALIGNMENT (CAUSED BY WORN CRANKSHAFT THRUST WASHERS)
—Replace worn and defective parts.
EXCESSIVE OIL IN CRANKCASE—Fill only to “FULL” mark on dipstick.
LOW OIL PRESSURE
(Check to be made with engine water outlet temperature of 160°F. minimum)
LUBRICATING OIL
SUCTION LOSS—Check oil level and bring to “FULL” mark on dipstick or correct installation
angle.
LUBRICATING OIL VISCOSITY-Check for the following:
1. Wrong Viscosity Lubricating Oil—Refer to “Engine Oil Viscosity Chart” in “Lubrication
System” section.
2. Plugged Oil Cooler—Clean oil cooler if oil temperature is abnormally high.
3. Fuel Oil Dilution—Check for fuel leaks at injector seal ring, and fuel jumper line
connections.
PRESSURE GAUGE
FAULTY GAUGE—Replace gauge.
GAUGE LINE OBSTRUCTED—Remove and clean line, replace if necessary.
ORIFICE PLUGGED—Remove and clean orifice.
CIRCULATION
FILTER CLOGGED—Remove and clean or replace element.
COOLER CLOGGED—Remove oil cooler and clean.
COOLER BY-PASS VALVE NOT FUNCTIONING PROPERLY-Remove by-pass valve, clean
valve and valve seat and inspect valve spring.
PRESSURE REGULATOR VALVE NOT FUNCTIONING PROPERLY-Remove pressure regu­
lator valve and clean and inspect spring.
EXCESSIVE WEAR OF CRANKSHAFT BEARINGS—Change engine bearings, clean oil pan,
refer to “Engine Oil Viscosity Chart” for proper grade, and change oil filter element.
GALLERY, CRANKSHAFT OR CAMSHAFT PLUGS MISSING-Replace plugs.
CHEVROLET SERIES 70-80 H E A V Y DUTY TRUCK SH O P M A N U A L