Fuel System-Bleeding

causym CAUTION: High-pressure fluid remaining in fuel lines can cause serious injury. Only technicians familiar with this type of system should perform repairs. Before disconnecting fuel lines, sensors, or any other components between the high-pressure fuel pump and nozzles on engines with High Pressure Common Rail (HPCR) fuel system, wait a minimum of 15 minutes after engine is stopped.

IMPORTANT: Do not attempt to pressurize the fuel tank with compressed air or any other means. Fuel tank and surrounding structural damage could result.

1. Close fuel supply gate valve (A).

2. Check fuel level and add clean diesel fuel if necessary.

NOTE: Greater fuel quantity in the tank will result in easier priming.


A-Fuel Supply Valve

TS1343
H78645

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3. Loosen fuel filter check valve inlet fitting (A) to allow air to pass.

4. Thoroughly clean area around precleaner bowl (B) and remove bowl. Remove any contaminates from bowl and screen. Inspect o-ring and reinstall bowl.

NOTE: Removing precleaner bowl is necessary to break any air lock between precleaner and fuel filter inlet check valve that may have occurred if machine was run out of fuel.

5. Open fuel supply gate valve. Precleaner should immediately fill with fuel.


A-Fuel Filter Check Valve
B-Fuel Precleaner Bowl

H78646
H78668

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6. Tighten fuel filter check valve (A) inlet fitting.

Specification

Low Pressure Fuel Line -Torque 27 N·m (20 lb-ft)


A-Fuel Filter Check Valve

H78646

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7. Loosen transfer pump outlet fitting (A) to allow air and fuel to bleed.

Unlock and operate hand primer (B) until steady fuel flow (free of air bubbles) is present out the transfer pump outlet fitting. Primer must be pulled up fully between pumps. Tighten fitting to specification.

Specification

Low Pressure Fuel Line -Torque 27 N·m (20 lb-ft)

NOTE: It can take up to 200 primer strokes until fuel flows steadily at this point if the system was emptied of fuel.

8. Loosen high pressure pump inlet fitting (C) on high pressure pump. Operate hand primer until steady fuel flow (free of air bubbles) is present out the high pressure pump inlet fitting. Primer must be pulled up fully between pumps. Tighten fitting to specification.

Specification

Low Pressure Fuel Line -Torque 27 N·m (20 lb-ft)

NOTE: It can take up to 200 additional primer strokes until fuel flows steadily at this point if the system was emptied of fuel.

9. Completely loosen and unseat high pressure line (D) on high pressure pump. Operate hand primer until steady fuel flow (free of air bubbles) is present out the open high pressure pump fitting. Tighten the fitting to specification.

Specification

High Pressure Pump Outlet Fitting -Torque 27 N·m (20 lb-ft)

H78621

High Pressure Pump


A-Transfer Pump Outlet Fitting (Low Pressure)
B-Hand Primer
C-High Pressure Pump Inlet Fitting (Low Pressure)
D-High Pressure Pump Outlet Fitting (High Pressure)
E-High Pressure Pump Outlet Fitting (High Pressure)

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NOTE: It can take up to 150 additional primer strokes until fuel flows steadily at this point if the system was emptied of fuel.

10. Completely loosen and unseat the high pressure line (E) on high pressure pump. Operate hand primer until steady fuel flow (free of air bubbles) is present out the open high pressure pump fitting. Tighten the fitting to specification and lock the hand primer.

Specification

High Pressure Pump Outlet Fitting -Torque 27 N·m (20 lb-ft)

NOTE: It can take up to 50 additional primer strokes until fuel flows steadily at this point if the system was emptied of fuel.

11. Start engine and run 3 to 5 minutes at low idle. DO NOT crank engine for more than 30 seconds. If engine does not start after three attempts or will not keep running, repeat steps 9- 11 until the engine starts and runs normally.

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