Rail Pressure Sensor - Comparison Test; Disconnecting The Pressure Sensor; Maintenance; 20 5.1.1 Replacing High-Pressure Hose - Bosch Diesel Set 3.1 Manual Original

4.2.3 Rail pressure sensor –
Comparison test
1. Connect the system diagnostic device (e.g. Bosch
KTS 5XX / 6XX) to the diagnostic connection on the
vehicle.
2. Open the rail pressure/sensor pressure actual value
in the diagnostic device's program.
3. Allow the engine to run and vary the rpm (either by
means of a test program or by depressing the acce-
lerator pedal).
i
Start-up takes longer, since the hose assembly must
first be filled!
Evaluation of the pressure display:
Pressure is less than 100 MPa:
"
The values shown on the pressure displays must not
differ from one another by more than 7 MPa (70 bar).
Pressures between 100 and 180 MPa:
"
The values shown on the pressure displays must not
differ from one another by more than 10 MPa.
 If the permissible variation is exceeded, the rail
pressure sensor of the vehicle must be replaced.
"
If the problem is not resolved by installing a new rail
pressure sensor, continue on the basis of the vehicle-
specific SIS trouble-shooting instructions (e.g. Bosch
ESI[tronic]).
4.2.4

Disconnecting the pressure sensor

!
The ignition must be switched off before the pressu-
re sensor is disconnected.
!
The display on the digital pressure display unit must
not show any pressure.
!
Loosen the first hose assembly connection slowly in
order to relieve any potential pressure spikes. Place
a lint-free cloth around the connection and tool
when doing this.
1. Disconnect the hose assembly from the rail.
2. Disconnect the pressure sensor.
3. Disconnect the digital pressure display unit.
4. Attach a new high-pressure hose assembly to the rail
and injector.
!
Follow the assembly instructions and observe the
tightening torque in the manufacturer's documenta-
tion.
5. Allow the engine to run and check the line connec-
tions for leaks.
6. Inspected visually for leaks after the test run.
Robert Bosch GmbH
Testing | Diesel Set 3.1 | 31
5.

Maintenance

5.1 Maintenance
The components of the diesel set must be inspected
and cleaned at regular intervals.
5.1.1 Replacing high-pressure hose

assemblies

¶
Replace blue high-pressure hose assemblies after
3 years.
¶
Replace black high-pressure hose assemblies after
6 years.
!
The high-pressure hose assemblies must be repla-
ced after the above-mentioned periods of time, even
if no safety-related deficiencies are obvious.
Always handle high-pressure hose assemblies with care
and inspect prior to use. Replace high-pressure hose
assemblies immediately if damage is found during the
inspection.
5.1.2

Checking the threads of high-pressure

hose assemblies

¶
Regularly inspect the threads of the union nuts for
damage.
¶
Replace damaged union nuts.
5.1.3 Checking the threads of pressure

sensors and the collecting rail

¶
Regularly inspect the threads of the hose fitting for
damage.
¶
If the threads are damaged, replace the pressure
sensor (fig. 1, item 12) and/or the collecting rail
(fig. 1, item 23).
!
The pressure sensor and collecting rail are safety-cri-
tical parts and may only be replaced in their entirety.
5.1.4

Checking the pressure sensor and

collecting rail

1. Regularly check the pressure sensor and collecting
rail for leaks at the hose fittings by means of a visual
inspection.
2. Regularly check the rail pressure sensor and pressu-
re limiter in the pressure sensor for leaks by means
of a visual inspection.
3. Check whether test oil can escape from the test oil
return connection on the pressure sensor. If it can,
the pressure limiter in the pressure sensor is defec-
tive.
!
The pressure sensor and collecting rail are safety-cri-
tical parts and may only be replaced in their entirety.
en
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1 689 989 210 2015-10-20