High-Pressure Fuel Lines Replacement

High-pressure lines are used between the fuel injection pump and the fuel injectors only. All high-pressure fuel Lines are of the same length and inside diameter. Correct high-pressure fuel line usage and installation is critical to smooth engine operation.

Whenever the high-pressure lines are removed, they should be removed as a bundle (if possible). They should also be tagged for return to original position.

CAUTION: The high-pressure fuel lines must be clamped securely in place in the holders. The lines cannot contact each other or other components. Do not attempt to weld high-pressure fuel lines or to repair lines that are damaged. Only use the recommended lines when replacement of high-pressure fuel line is necessary.

REMOVAL

CAUTION: Refer to Cleaning Fuel System Parts.

1. Disconnect both negative battery cables from both batteries. Cover and isolate ends of cables.
2. Thoroughly clean fuel lines at cylinder head and injection pump ends.

Fig. 48 Cable/Lever/Throttle Linkage Cover:

3. Remove cable cover (Fig. 48). Cable cover is attached with 2 Phillips screws, 2 plastic retention clips and 2 push tabs (Fig. 48). Remove 2 Phillips screws and carefully pry out 2 retention clips. After clip removal, push rearward on front tab, and upward on lower tab for cover removal. Do not remove any cables at lever.

Fig. 49 Wiring Clips At APPS:

4. Disconnect wiring harness (clip) at bottom of Accelerator Pedal Position Sensor (APPS) mounting bracket (Fig. 49).

Fig. 50 Air Tube (Typical):

5. Using 2 small screwdrivers, pry front wiring clip (Fig. 50) from cable bracket housing. Position wiring harness towards front of engine.

Fig. 51 Rear View Of APPS:

6. Remove electrical connector from APPS by pushing connector tab rearward while pulling down on connector (Fig. 51).

Fig. 53 Air Intake Housing (Rear View):

7. Disconnect 2 electrical cables from cable mounting studs (Fig. 53) at intake air heater on top of intake manifold.
8. Remove engine oil dipstick from engine.
9. Remove engine oil dipstick tube support mounting bolt (Fig. 53) and position tube to side.
10. Disconnect clamps and remove air tube (intake manifold-to-intercooler) (Fig. 50).

Fig. 52 Air Intake Housing (Front View):

11. Remove 4 air intake housing mounting bolts and remove housing (Fig. 52) and (Fig. 53)and Position ground cable at top of air intake housing to front of engine.

Fig. 54 Intake Manifold Air Heater (Elements):

12. Remove intake manifold air heater element block from engine (Fig. 54). Discard old upper and lower gaskets
13. Remove 3 cable bracket housing mounting bolts (Fig. 52). Carefully position cable bracket and cable assembly to side of engine. Leave cables connected to lever.

Fig. 55 High Pressure Lines At Cylinder Head:

14. Remove engine lifting bracket at rear of intake manifold (2 bolts) (Fig. 55).
15. Remove bolts from all fuel injection line support brackets at intake manifold.
16. Place shop towels around fuel lines at fuel injectors. Do not allow fuel to drip down side of engine.

CAUTION: WHEN LOOSENING OR TIGHTENING HIGH-PRESSURE FITTINGS AT INJECTION PUMP, USE A BACK-UP WRENCH ON DELIVERY VALVE AT PUMP DO NOT ALLOW DELIVERY VALVE TO ROTATE.

Fig. 56 High Pressure Lines At Fuel Injection Pump:

17. Loosen high-pressure line fittings at injection A pump beginning with cylinders 1, 2 and 4 (Fig. 56).
18. Loosen high-pressure lines at cylinder head for cylinders 1, 2 and 4 (Fig. 55).
19. Carefully remove front line bundle from engine. Do not bend lines while removing. While removing front line bundle, note line position.
20. Loosen high-pressure lines at injection pump beginning with cylinders 3, 5 and 6.
21. Loosen high-pressure lines at cylinder head for cylinders 3, 5 and 6 (Fig. 55).
22. Carefully remove rear line bundle from engine. Do not bend lines while removing. While removing rear line bundle, note line position.

INSTALLATION

CAUTION: Be sure that the high-pressure fuel lines are installed in the same order that they were removed.

1. Lubricate threads of injector line fittings with clean engine oil.
2. Loosen, but do not remove, all fuel line support bracket bolts.
3. Install rear injection line bundle beginning with cylinder head (fuel injector) connections, followed by injection pump connections. Tighten all fittings finger tight.
4. Tighten fittings at fuel injector ends for cylinders number 6 and 5 to 38 Nm (28 ft. lbs.) torque.
Do not tighten number 3 line at this time. It will be tightened during bleeding procedure.
5. Tighten 3 fittings at fuel injection pump ends to 24 Nm (18 ft. lbs.) torque.
6. Install front injection line bundle beginning with cylinder head (fuel injector) connections, followed by injection pump connections. Tighten all fittings finger tight.
7. Tighten fitting at fuel injector end for cylinder number 2 to 38 Nm (28 ft. lbs.) torque. Do not tighten lines number 1 or 4 at this time. They will be tightened during bleeding procedure.
8. Tighten remaining 3 fittings at fuel injection pump ends to 24 Nm (18 ft. lbs.) torque.
9. Install fuel line support bracket bolts to intake manifold and tighten to 24 Nm (18 ft. lbs.) torque.

CAUTION: Be sure fuel lines are not contacting each other or any other component. Noise will result.

10. Install engine lifting bracket at rear of intake manifold. Tighten 2 bolts to 77 Nm (57 ft. lbs.) torque.
11. Install cable bracket housing/cable assembly and tighten 3 mounting bolts to 24 Nm (18 ft. lbs.) torque.
12. Clean any old gasket material below and above intake manifold air heater element block. Also clean mating areas at intake manifold and air intake housing.
13. Using new gaskets, position intake manifold air heater element block to engine.
14. Install air intake housing and position ground cable. Install 4 mounting bolts and tighten to 24 Nm (18 ft. lbs.) torque.
15. Install air tube (intake manifold-to-inter-cooler) (Fig. 50). Tighten clamps to 8 Nm (72 in. lbs.) torque.
16. Install engine oil dipstick tube support mounting bolt and tighten to 24 Nm (18 ft. lbs.) torque.
17. Install engine oil dipstick to engine.
18. Connect 2 electrical cables to cable mounting studs.
19. Connect electrical connector to bottom of APPS by pushing connector upward until it snaps into position.
20. Connect wiring harness (clip) at bottom of Accelerator Pedal Position Sensor (APPS) mounting bracket (Fig. 49).
21. Connect front wiring clip (Fig. 50) to cable bracket housing.
22. Install cable cover (Fig. 48).
23. Connect both negative battery cables to both batteries.
24. Bleed air from fuel system. Do this at fuel injector ends of lines. Use cylinders numbers 1, 3 and 4 for bleeding. After bleeding, tighten fittings to 38 Nm (28 ft. lbs.) torque.
25. Check lines/fittings for leaks.