ROTOCOIL & 4N4975 - Caterpillar

Required Parts
Table 1
Required Tooling Quantity
323-3949 Test Kit 1
558-4574 Rail Plug As 1
356-0828 Fuel Injection Line As 1
356-5217 Fuel Injection Line As 3
356-0831 Fuel Injection Line As 1
356-0832 Fuel Injection Line As 2
9S-8927 Plugs 2
8S-4950 Caps 3
9S-5518 Plugs 2
9L-8493 Flared Caps 2
Fuel injection lines MUST only be used once. Discard all fuel injection lines after use.
Illustration 1 g02039499
323-3949 Test Kit
(1) 356-2468 Foam Lid
(2) 356-2470 Graduated Cylinder
(3) 356-2466 Plastic Case
(4) 323-3950 Discharge Orifice As
(5) 323-8301 Pump Drain Hose
(6) 355-8794 Gage Pin
(7) 356-2469 Foam Block
(8) 355-8626 Nut
(9) 558-4574 Rail Plug As(1)Test Procedure
Contact with high pressure fuel may cause personal injury or death. Wait 60 seconds after the engine has stopped to allow fuel pressure to purge before any service or repair is performed on the engine fuel lines.
Before beginning any work on the fuel system, refer to Operation and Maintenance Manual, "General Hazard Information and High-Pressure Fuel Lines" for safety information.Refer to Systems Operation, Testing and Adjusting, "Cleanliness of Fuel System Components" for detailed information on the standards of cleanliness that must be observed during all work on the fuel system.
Note: Use the gage pin (6) or an aerosol cleaner to ensure that the orifice is clean before performing this procedure.Test Step 1: Measure the Fuel Leak From the Pressure Relief Valve (PRV)
Illustration 2 g06258452
(1) Pressure Relief Valve (PRV) fuel line
Remove fuel return line (1) from the PRV on the high-pressure fuel rail to the low-pressure regulator block.
Cap the port at the regulator block using the 9L-8493 Flared Cap.
Route the PRV fuel line into graduated cylinder (2).Note: Ensure that the PRV fuel line does not have any obstructions or residual fuel.
Use the Cat® Electronic Technician (ET) "Injection Disable Override" to disable the fuel injectors or disconnect the fuel injectors electrical connector on the side of the cylinder head.Note: Leave the injectors disabled during the test.
Turn the keyswitch to ON for 30 seconds to prime the fuel system. After priming has been completed, crank the engine for 20 seconds and record the fuel volume that collects in the graduated cylinder.
If the measured volume of fuel is more than 5 drops, replace the PRV. Repeat the test to verify the repair. Proceed to Test Step 4.
If the measured volume of fuel is fewer than 5 drops, reinstall the PRV fuel line to the low-pressure regulator block. Proceed to Test Step 2.Test Step 2: Measure the Pressure and Flow of the Fuel Rail while Cranking
Illustration 3 g06258456
(3) High-pressure fuel supply line
(5) 323-3950 Discharge Orifice AsNote: Illustration 3 shows discharge orifice assembly (5) attached to injector supply line number 3. The discharge orifice assembly can be installed to any injector supply line as long as the other 5 injectors ports are plugged on the fuel rail.
Remove the fuel lines for the injectors from the fuel rail.
Install the 558-4574 Rail Plug As on the rail for cylinders 1, 2, 4, 5, and 6.
Use the 355-8794 Gage Pin to ensure that the discharge orifice is free of any obstruction.