Detroit Diesel — Removal of High Pressure Fuel Line and Transfer Tube
Repair & overhaul
From a Detroit Diesel service manual — check it applies to your exact model before use.
Before you start
- High pressure fuel can penetrate skin; residual high fuel pressure may be present in the circuit.
- Keep all potential ignition sources away from diesel fuel; do not smoke when refueling.
- Wear a face shield or goggles to avoid injury from sudden release of a high pressure hose connection.
- The high pressure fuel line and transfer tube are one-time use items; failure to install new parts will cause fuel leaks and high pressure fuel line failures.
Procedure
- Remove both engine trim covers.
- Remove the cylinder head cover for each cylinder head.
- Remove the intake manifold.
- Secure the transfer tube thrust nut with a 24 mm fuel line wrench (J-47484 or J-45063).
- Loosen the high pressure fuel line nut at the transfer tube with a 17 mm fuel line wrench (J-47483) or 17 mm open end wrench.
- Loosen the high pressure fuel injector line nut at the injector unit pump with a 17 mm wrench; discard the line.
- Loosen the transfer tube thrust nut with a 24 mm fuel line wrench (J-45063 or J-47484); remove and discard the transfer tube and O-ring.
Tools required
- 24 mm fuel line wrench J-47484 or J-45063 Amazon
- 17 mm fuel line wrench J-47483 Amazon
- 17 mm open end wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Ensure the engine has been shut down for a minimum of 10 minutes before servicing any component within the high pressure circuit
Source: Detroit Diesel service 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.