Thermo King T-1000R, Maintenance Manual

Page: 150 / 282

Engine Maintenance 9-12
Testing the Coolant Level Switch
You can test the switch in the unit by adjusting the coolant level. You can also remove the coolant level switch from the
expansion tank and test the switch by moving the float up and down.
1. Remove the wire harness connector from the coolant level switch.
2. Use an ohmmeter to check the continuity of the switch at the connection pins.
3. Make sure the coolant level is above the switch and check the continuity of the switch. The switch should be closed. If you
removed the switch from the tank, do this check with the float in the upper position.
4. Drain coolant from the expansion tank until the coolant level is well below the switch and check continuity of the switch. The
switch should be open. If you removed the switch from the tank, do this check with the float in the lower position.
5. Replace the switch if it is not closed in step 3 and does not open in step 4.
Replacing the Coolant Level Switch
1. Disconnect the wire harness connector from the coolant level switch.
2. Drain coolant from the expansion tank until the coolant level is well below the switch.
3. Remove (unscrew) the coolant level switch from the expansion tank.
4. Install the new coolant level switch and position the orientation mark down as shown in the following drawing.
5. Refill the expansion tank with coolant.
6. Connect the wire harness connector to the coolant level switch.
ENGINE FUEL SYSTEM
The fuel system used on these diesel engines is a high pressure system used in conjunction with a prechamber.
The components of the fuel system are:
• Fuel tank (may be the truck fuel tank)
• Electric Fuel pump
• Fuel filter
• Injection pump
• Injection nozzles.
Operation
A 10 psig (69 kPa) electric fuel pump pulls fuel from the fuel tank through a prefilter, then pushes it to the fuel filter, and to
the injection pump. The prefilter is designed for diesel fuel and is the only type that should be used.
The injection pump raises the pressure of the fuel and meters the correct amount of fuel to the nozzle at the correct time. The
increased fuel pressure will lift the spring loaded nozzle to admit fuel into the combustion chamber.
Maintenance
The fuel system is relatively trouble free, and if properly maintained will usually not require major service repairs between
engine overhauls.
1. Orientation Mark Down
Coolant Level Switch
1