Fuel Rail: Service and Repair
WM 243019 Removing and installing fuel distributor pipe
Tools
Preliminary work
1. Disconnect the battery. For instructions, see -> 270619 Removing and installing battery Removal and Replacement and -> 2X00IN Work instructions after disconnecting the battery 2X00IN Work instructions after disconnecting the battery
2. Remove intake-air distributor -> 244619 Removing and installing intake-air distributor - section on "Removing" Overhaul.
Removing fuel distributor pipe
WARNING
Toxic substances
- Danger of poisoning or suffocation
-> Ventilate the work area well.
-> Never ingest or inhale.
-> Read specific information on the Hazard Sheet.
-> Wear personal protective gear.
WARNING
Highly inflammable or explosive materials
- Danger of fire or explosion
-> Avoid contact with hot parts or sources of ignition.
-> Use suction to remove ignitable vapours.
-> Attach warning sign in a clearly visible position.
NOTICE
Dirt on injection system components (intake manifold injection and direct fuel injection system)
- Material damage
- Rough-running engine
- Bad exhaust emissions
-> Thoroughly clean connection points and adjacent areas before loosening them. If the engine is very dirty, wash it before starting disassembly work.
-> Lay removed parts on a clean surface and cover them. Do not use fibre-shedding cloths.
-> Carefully cover components or seal them if repair work will not be carried out immediately. Place rubber caps on connections. Seal intake openings with film or adhesive tape.
-> Only install clean parts. Do not take spare parts out of the packaging until just before installation.
-> Never use compressed air when the system is open. Do not move the vehicle.
WARNING
Leaking fuel supply lines
- Emerging fuel
- Risk of fire
-> Perform leak test.
Information
- Do not bend high-pressure lines. Always remove the high-pressure distributor pipe and other fuel-supply components in the high-pressure area completely. Check that the connection points are not damaged and are perfectly clean and make sure there is no thread damage. Fit union nuts on all connection points by hand before screwing in screws or bolts. Remove dirt on the conical/ball joints. Check connection points for leaks following fitting.
Information
- The ignition must be switched off when working on the fuel system.
- Absorb any escaping fuel using a suitable binding material or a cloth.
- Cloths which have absorbed fuel must be disposed of according to the applicable national laws.
- The fuel system must be depressurised before starting work on it.
- Only work on the fuel system in well-ventilated rooms.
- Any seals which have been removed must always be replaced.
Component overview
1. Unplug electric plug connection on the high-pressure sensor -2-.
High-pressure fuel distribution
2. Place a cloth around the high-pressure connection on the high-pressure line -3-.
Relieve the fuel pressure by slowly opening the high-pressure line with an open-ended wrench.
3. Loosen all eight union nuts for the high-pressure fuel injectors -1-.
Use an open socket socket-wrench insert Nr.18-1 or similar tool to do this => Socket.
Socket
4. Remove screws on fuel distributor pipe (fuel rail) -1 and 2- and lift off fuel rail.
The screw on the thermostat housing is longer.
The rear right screw can only be reached using a thin Torx wrench.
Mount for fuel distributor pipe
5. Remove fuel rail from the engine by twisting it -arrow-.
Fuel rail in engine
Installing fuel distributor pipe
WARNING
Loose purge connection
- Emerging fuel
- Risk of fire
-> Check that the purge connection of the fuel distribution pipe is seated securely.
-> Tighten the purge connection of the fuel distribution pipe to the correct tightening torque.
Information
- The tightening specifications for the basic engine are stored centrally. -> 1001IN Tightening torques, tightening sequences, assembly overviews [1][2]Specifications. Tightening torques and assembly instructions for other assemblies (e.g. chassis, electrics, transmission or body) or for peripheral engine equipment can be found in the corresponding documents.
Fuel distributor pipe
1. Using the leak test equipment, blow the fuel out of the high-pressure pump and the high-pressure line into a cloth.
Shake the fuel distributor pipe over a cloth to remove fuel residues. -> 243001 Checking fuel distributor pipe for leaks Testing and Inspection.
2. Fit fuel rail on the engine by twisting it -arrow-.
Fuel rail in engine
Information
When fitting the union nuts, make sure that the connection taper of the high-pressure line is loose in the injector. It should be possible to screw on the union nut easily without greasing it and without the use of force (check that it is straight and screws on easily). Loosen the injector retainers and correct the positions of the various components if necessary.
3. Fit fuel rail.
High-pressure fuel distribution
3.1. Carefully lift up the coolant vent line at the rear if necessary and slide the fuel rail into installation position.
3.2. Screw fuel rail on loosely. Screw union nuts loosely onto the injectors.
Information
When fitting the union nuts, make sure that the connection taper of the high-pressure line is loose in the injector. It should be possible to screw on the union nut easily without greasing it and without the use of force (check that it is straight and screws on easily). Loosen the injector retainers and correct the positions of the various components if necessary.
Only fit screws and union nuts -1- loosely until everything fits!
3.3. Also fit the high-pressure line -3- between the rail and high-pressure pump.
4. Fit screws on fuel distributor pipe (fuel rail) -1 and 2-.
The screw on the thermostat housing is longer.
The rear right screw can only be reached using a long, thin Torx wrench.
Mount for fuel distributor pipe
5. When all threaded joint positions fit correctly and without tension, tighten all threaded joints according to the prescribed tightening torques.
The union nuts for the injectors and the high-pressure feed line must first be tightened initially, then loosened and then tightened finally.
Use an open socket socket-wrench insert Nr.18-1 => Socket or similar tool to screw on the injectors.
Fasten the high-pressure line with an open-ended socket ring wrench Nr.185 and a torque wrench.
It is essential to comply with the tightening torques -> 1001TW Tightening torques, tightening sequences, assembly overviews [1][2]Specifications.
Socket
6. Check the high-pressure system for leaks. -> 243001 Checking fuel distributor pipe for leaks Testing and Inspection.
7. Plug in electric plug connection on the high-pressure sensor. -2-
High-pressure fuel distribution
Subsequent work
1. Fit intake-air distributor -> 244619 Removing and installing intake-air distributor - section on "Installing" Overhaul.
2. Connect the battery. For instructions, see -> 270619 Removing and installing battery Removal and Replacement and -> 2X00IN Work instructions after disconnecting the battery 2X00IN Work instructions after disconnecting the battery