User Manual

36 RENR9968-02
Testing and Adjusting Section
Back pressure is the difference in the pressure
between the exhaust at the outlet elbow and the
atmospheric air.
Hot engine components can cause injury from
burns. Before performing maintenance on the
engine, allow the engine and the components to
cool.
Making contact with a running engine can cause
burns from hot parts and can cause injury from
rotating parts.
When working on an engine that is running, avoid
contact with hot parts and rotating parts.
1. Connect the pressure port of the differential
pressure gauge to the test location. The test
location can be located anywhere along the
exhaust piping after the turbocharger but before
the m uffler.
2. Leave the vacuum port of the differential pressure
gauge open to the atmosphere.
3. Start the engine. Run the engine in the no-load
condition at high idle.
4. Record the value.
5. Multiply the value from Step 4 by 1.8.
6. Compare the result from Step 5 to the value that
follows.
Back pressure from the exhaust must not be more
than the following amount:
Maximum back pressur e ........................ 6.8 kPa
(27.33 inch of H
2
O)
i02030344
Turbocharger - Inspect
SMCS Code: 1052-040
Disconnect batteries before performance of any
service work.
Hot engine components can cause injury from
burns. Before performing maintenance on the
engine, allow the engine and the components to
cool.
NOTICE
Keep all parts clean from contaminants.
Contaminants may cause rapid wear and shortened
component life.
NOTICE
Caremustbetakentoensurethatfl uids are contained
during performance of inspection, maintenance, test-
ing, adjusting and repair of the product. Be prepared to
collect the fluid with suitable containers before open-
ing any compartment or disassembling any compo-
nent containing fluids.
Refer to Special Pu blication, NENG2500, “Caterpilla r
Tools and Shop Products Guide” for tools and supplies
suitable to co llect and contain flu ids on Caterpillar
products.
Dispose of all fluids according to local regulations and
mandates.
Before you begin inspection of the turbocharger,
be sure that the inlet air restriction is within the
specifications for your engine. Be sure that the
exhaust system restriction is within the specifications
for your engine. Refer to Systems Operation/Testing
and Adjusting, “Air Inlet and Exhaust Syst em -
Inspect”.
The condition of the turbocharger will have definite
effects on engine performance. Use the following
inspections and procedures to determine the
condition of the turbocharger.
•
Inspection of the Compressor and the Compressor
Housing
•
Inspection of the Turbine Wheel and the Turbine
Housing
Inspection of the Compressor and
the Compressor Housing
Remove air piping from the compressor inlet.