Checking The Turbo Charger; Check Rotation Of The Impeller; Check The Radial Clearance Of The Impeller; Check Operation Of The Control Device - Nanni T4.155 Workshop Manual

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CHECKING THE TURBO CHARGER

1. CHECK ROTATION OF THE IMPELLER

Take the edge of the turbine impeller and rotate it. Verify that the
impeller turns without offering any resistance.
If the impeller does not turn, or if it turns and rubs, replace the turbo
charger.
2. CHECK THE AXIAL CLEARANCE OF THE
IMPELLER
Put the dial gauge in the side intake hole of the impeller edge and
check the axial clearance.
Maximum nominal clearance: 0.173 mm
If the axial clearance is not within the limits stipulated in the
specification, replace the turbo charger.
3. CHECK THE RADIAL CLEARANCE OF THE
IMPELLER
a. Working from the oil delivery connector side, fit the dial gauge
in the centre part of the impeller shaft.
b. Move the impeller shaft in the radial direction and measure the
radial clearance of the impeller shaft.
Maximum nominal clearance: 0.110 mm
If the radial clearance is not within the limits stipulated in the
specification, replace the turbo charger.

4. CHECK OPERATION OF THE CONTROL DEVICE

a. Disconnect the flexible pipe of the control device.
b. Use special maintenance tool SST to apply a pressure of
approximately 116 kPa (1.18 kgf/cm²) to the control device and
verify that the control rod moves.
If the control rod does not move, replace the complete turbo charger.
REMARK:
Never apply a pressure greater than 127 kPa (1.30
kgf/cm²) to the control device.
4 CYLINDERS WORKSHOP MANUAL 160/191