Bleeding the Fuel System (Engines With Electronic Fuel Systems And Bosch VP44 Pump)

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High-Pressure Fluids

CAUTION: Escaping fluid under pressure can penetrate the skin causing serious injury. Relieve pressure before disconnecting fuel or other lines. Tighten all connections before applying pressure. Keep hands and body away from pinholes and nozzles which eject fluids under high pressure. Use a piece of cardboard or paper to search for leaks. Do not use your hand.

If ANY fluid is injected into the skin, it must be surgically removed within a few hours by a doctor familiar with this type injury or gangrene may result. Doctors unfamiliar with this type of injury may call the Deere & Company Medical Department in Moline, Illinois, or other knowledgeable medical source.

Bleed the fuel system anytime the fuel system has been opened up. This includes:

• After fuel filter changes.
• After pump or nozzle replacement.
• Anytime fuel lines have been disconnected.
• After engine has run out of fuel.

This fuel system can only be bled by the electronic transfer pump or at the injection nozzles. BLEEDING SHOULD NOT BE PERFORMED at any location on the Bosch VP44 injection pump.

IMPORTANT: NEVER pressurize the fuel tank to prime the fuel system as it could rupture seals in the injection pump.

Bleed Using Electronic Transfer Pump

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Bleed Fuel System

A - Bleed Orifice in Final Fuel Filter Base

B - Fuel Return Line

The bleed is automatically performed by a small orifice (A) inside the final fuel filter base connected to the overflow valve on injection pump. The system allows air to escape continually through the fuel return line (B) when ignition is ON.

1. Ignition ON.

2. Allow 40 seconds for electronic transfer pump to complete priming.

3. If additional system bleeding is required, bleed the circuit by loosening fuel line connections at injection nozzles. See the next procedure, BLEED FUEL SYSTEM AT FUEL INJECTION NOZZLES.

Bleed Fuel System at Fuel Injection Nozzles

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Bleed At Fuel Injection Nozzles

1. IMPORTANT: Always use a backup wrench when loosening or tightening fuel lines at nozzles and/or injection pump to avoid damage.

   Using two open-end wrenches, loosen two fuel line connections at injection nozzles.

2. Crank engine over with starter motor for 15 seconds (but do not start engine) until fuel free from bubbles flows out of loosened connection. Retighten connection to specifications.

   Item	Measurement	Specification
   Fuel Injection Nozzle Delivery Line	Torque	27 N˙m (20 lb-ft)

3. Repeat procedure for remaining injection nozzles (if necessary) until all air has been removed from fuel system.