Bleeding the Fuel System (Tractors Equipped with Bosch VP44 Injection Pump)

CAUTION: Escaping fluid under pressure can penetrate the skin causing serious injury. Avoid the hazard by relieving pressure before disconnecting hydraulic or other lines. Tighten all connections before applying pressure. Search for leaks with a piece of cardboard. Protect hands and body from high pressure fluids.

If an accident occurs, see a doctor immediately. Any fluid injected into the skin must be surgically removed within a few hours or gangrene may result. Doctors unfamiliar with this type of injury should reference a knowledgeable medical source. Such information is available from Deere & Company Medical Department in Moline, Illinois, U.S.A.

Every time the fuel system is been opened up for service (lines disconnected or filters removed), it will be necessary to bleed air from the system.

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.

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

1. Turn key in main switch to the right as far as the first switch position so that the fuel transfer pump is operating.

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".

A-Bleed Orifice in Filter Base
B-Overflow Valve
C-Fuel Return Line

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1. Place throttle lever in half-throttle position.

On engines equipped with electronic fuel shut-off solenoid, energize solenoid.

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

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

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

Specification

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

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