TRUCK SERVICE MANUAL
Operation and Maintenance
it down to allow lubricating oil to carry heat away.
Correlated action of compressor and turbine automatically
adjust speed and output of turbocharger to compensate
The turbocharger contains bearings and seals that are subject
engine speed and load changes.
to the high heat of combustion exhaust gases. While the
engine is running, this heat is carried away by oil circulation,
Consideration
need
not be given to direction of
but If the engine is stopped suddenly, the turbocharger
turbocharger rotation when applied to right-hand-left-hand
temperature may rise as much as 100 deg. F [38 deg. C] .
engines Turbocharger rotates in only one direction, regard less
of direction of engine rotation.
The results of extreme heat may be seized bearings, bearing
housing deformation or burned "0" ring oil seals.
Under continuous load operation, exhaust smoke from a
turbocharged engine should not be too dense, however, rapid
Place warning decal (Bulletin No. 983361B), Fig 103, In a
acceleration may cause a turbocharged engine to show
conspicuous location.
exhaust smoke of greater density for a few seconds until the
turbocharger rpm catches up with sudden increase in fuel
supply.
CAUTION
Starting And Initial Checks
PROTECT THE
TURBOCHARGER
1. Prelubricate turbocharger by pouring clean lubricating
DURING
oil through inlet opening. Turn rotating assembly by hand to
coat bearings and thrust washer with oil.
START-UP BY NOT OPENING
2. Install oil inlet line and fill with clean lubricating oil.
THROTTLE OR ACCELERATING
Use wire braid hose with minimum inside diameter of 5/16 inch
ABOVE 1000
RPM UNTIL NORMAL
[7.9 mm] (SAE No. 6) that will withstand up to 450 deg. F
ENGINE IDLE SPEED OIL PRESSURE
[232 deg. C] oil temperatures.
REGISTERS ON GAUGE.
3. During initial starting, check for oil pressure at inlet
SHUT-DOWN BY IDLING THREE
connection to turbocharger (10 psi [69 kPa] minimum at idle).
(3) MINUTES BEFORE SHUT-OFF.
4. Disconnect oil drain line to determine If oil is flowing
Cummins Engine Company, Inc.
through turbocharger. Reconnect line.
Columbus, Indiana, U.S.A. 47201
Bulletin No. 983361-B 7-70
5 Remove air inlet connection from turbocharger and
observe rotation of turbocharger rotor. The rotor must be
Fig. 10-3, T-335-A. Shut-down decal 983361-B
entirely free of any evidence of rubbing or binding.
6. Shut down engine momentarily to determine If rotor
Lubricating Oil Flow
coasts freely to a stop
To check lubricating oil flow at turbocharger, loosen oil drain
7. Restart engine and check full speed and load.
line to see that oil is flowing while engine is running
Turbocharger oil must be kept clean by regular changing of
8. Recheck all connections and piping for tightness.
engine oil filter elements.
If no leakage of oil, air or exhaust gas can be noted, the
engine is ready for operation.
Turbocharger Speed
9. Performance of turbocharger must be observed at
Ordinarily, attention need not be given to the speed of the
reasonable intervals. Data and conditions to be observed are
noted in following paragraphs
Engine Shut-Down
It Is important to Idle an engine 3 to 5 minutes before shutting
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