Vacuum Test; Pressure Test - Bosch SMT 300 Manual Original

en 30 | SMT 300 | Operation
6.3 Leakage test with pressure gauge
6.3.1

Vacuum test

!
A vacuum greater than -70 mbar damages the pres-
sure gauge of the SMT 300.
1. Disconnect the voltage supply of the SMT 300.
2. Disconnect the compressed-air supply of the
SMT 300.
3. Remove the Delrin® nozzle from the smoke supply
hose
4. Connect the smoke supply hose to the T-piece (not
included in delivery).
5. Connect the T-piece to the system to be tested.
6. Connect the T-piece to the manual vacuum pump.
7. Create a vacuum.
8. Observe the vacuum indicator on the pressure gauge
of the SMT 300 to ensure that a vacuum greater than
-70 mbar is not drawn.
9. End vacuum generation when the correct vacuum or
a vacuum of -70 mbar has been reached.
10. Observe the indicator for a loss of vacuum.
i
A loss of vacuum indicates leakage.
i
Pressure drop / loss in vacuum tests cannot deter-
mine the extent of leakage; this requires a test via
the flow meter; see sec. 6.5.
6.3.2

Pressure test

!
A gauge pressure greater than 70 mbar damages the
pressure gauge of the SMT 300.
1. Turn the smoke flow control to position "TEST".
2. Press the power key.
 The system starts to fill.
3. Fill the SMT 300 completely.
 The pressure gauge display reads between
50 mbar and 70 mbar.
4. Press the power key.
 Filling of the SMT 300 switches off.
5. Watch the pressure display for a pressure drop over
an extended period of time.
i
A pressure drop indicates leakage.
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6.4 Leakage test with the flow meter
6.4.1 Solenoid valve test
1. Fill the system to be tested with the tester at the
setting "TEST".
2. Test the solenoid valve at the open and closed posi-
tions of the solenoid valve.
i
On closing the solenoid valve, the ball in the flow
meter should drop. If flow is indicated with the sole-
noid valve closed, the solenoid valve has leakage.
6.4.2 EVAP test
!
All tests with the SMT 300 must be carried out with
the vehicle engine switched off.
!
Due to possibly explosive gases from the fuel tank,
the EVAP test must not be performed with a com-
pressed-air connection. A gas bottle with inert
gas (nitrogen, argon or CO
EVAP test.
i
To save time, the system to be tested can be filled
with the tester set to "SMOKE" instead of to "TEST".
Test set-up
SMT 300
Fig. 8: EVAP test with
1 Flow meter
2 Connection for gas bottle with inert gas
i
The flow meter is active at all settings of the smoke
flow control. The most accurate determination of the
extent of leakage, however, uses the setting "TEST"
and the procedure described in the following.
) must be used for the
2
Robert Bosch GmbH