High-pressure pipe: Replacement

K9K

Essential special tools
Mot.1566	High-pressure pump pipe removal tool

Essential equipment

diagnostic tool

pipe union tool for tightening the high-pressure pump-to-rail pipe ("Crowfoot 19-17" spanner)

high-pressure pipe spanner (DM19 spanner)

crowfoot pipe attachment for tightening the injector-to-rail high-pressure pipes ("Crowfoot 18-17" spanner)

"low torque" torque wrench

Tightening torques
rail mounting nuts	2,8 daN.m
"pump - rail" high-pressure pipe nuts	3.8 daN.m
"rail - injectors" high-pressure pipe nuts	3.8 daN.m
cover nut on rail	3.8 daN.m

IMPORTANT

Before any work on the injection system, use the diagnostic tool to check:

• that the injection rail is no longer under pressure,
• that the fuel temperature is not high.

• Always observe the safety and cleanliness instructions given in this document during every operation.
• Never loosen a high-pressure pipe connection while the engine is running.

WARNING

• Use the special plug kit for the high-pressure injection circuit.
• Always replace any high-pressure pipe and the high-pressure pipe clips that were removed.

REMOVAL

• Disconnect the battery.
• Remove the engine covers.

• Disconnect the air intake duct (1).

• Remove the diesel splash guard (2).

• Remove the oil dipstick guide tube (3).
• Fit protective caps to the openings.
• Carefully disconnect:

• the glow plugs (4),
• the injectors (4),
• the high-pressure pump electrical connectors (5),
• the diesel supply and return pipes (6).

• Carefully disconnect:

• the diesel return pipe (7) connecting the injectors to the high-pressure injection pump,
• the injection rail pressure sensor (8),
• the accelerometer (9),
• the oil level probe (10),
• the cylinder identification sensor on the timing cover (11).

• Move the wiring harness aside.
• Remove the cover (12) located on the injection rail.

WARNING

• Always hold the injector intermediate fitting with a spanner when loosening the high-pressure pipes.
• Do not damage the injector leak-off return tube.

• Loosen the injection rail mounting nuts (13) by a few turns.
• Remove the clips (14) joining the high-pressure pipes together.
• Loosen:

• the high-pressure pipe nut on the injector end, using tool (Mot.1566),
• the high-pressure pipe nut on the injection rail end, using tool (Mot.1566).

Note: Loosen the nuts pipe by pipe.

• Slide the nuts along the pipe while keeping the olive in contact with the cone.

• Remove the high-pressure pipes (17) one at a time.
• Fit protective caps to the openings.

INSTALLATION

WARNING

• Before fitting a high-pressure pipe, lightly lubricate the nut threads with the oil in the sachet supplied in the new parts kit.
• Take care not to introduce oil into the high-pressure pipe.
• Do not lubricate high-pressure pipes supplied without a sachet; these pipes are self-lubricated.

CAUTION: Remove the caps only at the last moment for each component.

I - REFITTING THE HIGH-PRESSURE PIPE "PUMP - RAIL"

• Remove the plugs.
• Seat the high-pressure pipe flared end in the high-pressure outlet cone of the high-pressure pump.
• Position the olive of the high-pressure pipe in the cone at the inlet of the spherical injection rail.
• Start the high-pressure pipe nuts by hand, beginning with the rail-side nut.
• Pre-tighten the high-pressure pipe nuts lightly.

II - REFITTING THE HIGH-PRESSURE PIPES "RAIL - INJECTORS"

• Remove the plugs.
• Position the olive of the high-pressure pipe in the high-pressure inlet cone of the injector.
• Position the olive of the high-pressure pipe in the high-pressure outlet cone of the rail.
• Start the high-pressure pipe nuts by hand, beginning with the nut on the injector side.

  Pre-tighten the high-pressure pipe nuts lightly.

WARNING

When tightening the high-pressure pipes, it is essential to hold the injector intermediate fitting (15).

Note: The fitting order of the rail-to-injector pipes is not important.

• Fit a new clip supplied with the new high-pressure pipe:

• insert the first half-shell using multi-grip pliers,
• insert the second half-shell using multi-grip pliers.

Note: Observe the fitting direction (the lugs only engage in one position).

III - REFITTING THE HIGH-PRESSURE PIPE "PUMP - RAIL" AND THE HIGH-PRESSURE PIPES "RAIL - INJECTORS"

• Tighten the rail mounting nuts to torque (2.8 daN.m).

WARNING

• Do not turn the high-pressure pipes with the spanner while tightening.
• Always hold the injector intermediate fitting with a spanner while tightening.

• Tighten the high-pressure pipe "pump - rail" nuts in sequence and to torque (3.8 daN.m):

• pump end,
• rail end.

Use the flare-nut crowfoot for tightening the pump-rail high-pressure pipe ("Crowfoot 19-17" spanner) or the high-pressure pipe spanner (DM19).

• Tighten the high-pressure pipe "rail - injectors" nuts in sequence and to torque (3.8 daN.m):

• injector side,
• rail end.

Use the flare-nut crowfoot for tightening the injector-rail high-pressure pipes ("Crowfoot 18-17" spanner) or the high-pressure pipe spanner (DM19).

Note: Fully tighten one pipe before moving to the next pipe.

• Refit in the reverse order of removal.
• Prime the diesel circuit using the priming bulb.
• Tighten the wiring duct nut on the rail to torque (2.1 daN.m) using a "low torque" torque wrench.

WARNING

Connect the battery; carry out the necessary re-learns (see Electrical Equipment chapter).

WARNING

Check for diesel leaks:

• check the seal after the repair (Diesel Injection chapter, High-pressure pipe: Sealing check, page 13B-48),
• run the engine at idle until the radiator fan starts,
• rev the engine several times with no load,
• carry out a road test,
• switch off the ignition,
• check that no diesel is leaking.