Page 317 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

Testing a fuel pump

1 Safety First: Always work in a well-ventilated area away from sparks, open flames, or sources of ignition.
Disconnect the battery’s negative terminal to prevent accidental sparks.
2 Access the Fuel Pump: Locate the fuel pump. It’s usually in the fuel tank, accessible through either an access
panel under the rear seat or by dropping the tank itself. Refer to the vehicle manual for specific instructions.
3 Relieve Fuel System Pressure: Before testing, relieve the fuel system pressure. This is typically done by
locating the fuel pump relay or fuse in the engine compartment fuse box and removing it. Then, start the engine
and let it run until it stalls. Crank the engine a few more times to ensure any remaining pressure is released.
4 Prepare Testing Equipment: Gather the necessary tools, including a fuel pressure gauge and a flow meter if
needed. Make sure they’re compatible with your vehicle’s fuel system.
5 Connect the Pressure Gauge: Follow the manufacturer’s instructions to connect the fuel pressure gauge to the
fuel rail or fuel line. This usually involves removing the fuel line and attaching the gauge with adapters.

6 Turn on the Ignition: Turn the ignition key to the “ON” position without starting the engine. This will activate the
fuel pump and pressurize the system.
7 Check Pressure Reading: The fuel pressure gauge should display the pressure within the specified range for
your vehicle. Refer to the service manual for the correct pressure specifications. If the pressure is too high or
too low, it could indicate a problem with the fuel pump or other components.
8 Test Flow Rate (Optional): If needed, you can test the fuel pump’s flow rate using a flow meter. This involves
collecting fuel pumped by the fuel pump for a specified time period and measuring the volume. Compare the
result to the manufacturer’s specifications.

9 Inspect for Leaks: While the fuel pump is running, inspect the fuel lines, connections, and fittings for any signs
of leaks.
10 Shut off the Ignition: Once testing is complete, turn off the ignition and disconnect the fuel pressure gauge.
Reinstall any components that were removed.
11 Verify Repairs: If you found any issues during testing, make the necessary repairs or replacements to ensure
the fuel pump is functioning properly.

12 Reconnect Battery: Reconnect the battery’s negative terminal and start the engine to verify that the fuel system
is operating correctly.

Procedure as per the Manufacturer for Dismantling,

Inspecting and Assembling Inline Pump

Objectives : At the end of this lesson you shall be able to
• service Inline fuel pump as per manufacturer procedure.

Step -1
Prepare: Prepare necessary equipment and safety equipment. Make sure the pump is off and the power source
is off.
Step - 2
• Remove any protective covers.
• Disconnect the pump from the piping system.
• Remove any fluid remaining in the piping and pump.

• Remove the bolts holding the pump casing together.
• Carefully separate the cover to expose the internal components.
• Remove the shaft, bearings, impeller, seals and other internal parts.

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CITS : Automotive - Mechanic Diesel - Lesson 94 & 95