John Deere — Bleeding the Fuel System
Maintenance
From a John Deere owner's manual covering: 4045TF120, 6068HF158, 6068TF120, 6068TF250. Check it applies to your exact model before use.
Applies to: John Deere 4045TF120, John Deere 6068TF120, John Deere 6068TF250
Before you start
- Escaping fluid under pressure can penetrate the skin causing serious injury.
- NEVER loosen screw securing pump head on Lucas rotary pumps, otherwise pump damage may occur.
Procedure
- Loosen the air bleed vent screw two full turns by hand on fuel filter base.
- Operate supply pump primer lever until fuel flow is free from air bubbles.
- Tighten bleed plug securely, continue operating hand primer until pumping action is not felt. Push hand primer inward as far as it will go.
- Start engine and check for leaks.
- At fuel injection pump (Stanadyne): slightly loosen fuel return line connector. Operate primer lever until fuel without bubbles flows. Tighten return line connector to 27 N·m (20 lb-ft).
- At fuel injection nozzles: move engine speed control to half throttle. Loosen fuel line connection at injection nozzle.
- Crank engine over with starter motor (but do not start engine) until fuel free from bubbles flows out.
- Retighten connection to 27 N·m (20 lb-ft). Repeat for remaining injection nozzles.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Fuel Return Line Connector (Stanadyne) 27 N·m (20 lb-ft)
- Fuel line connection at injection nozzle 27 N·m (20 lb-ft)
Full service-parts list: John Deere 6068TF250 →
Source: John Deere owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.