Fuel Supply Line: Service and Repair
WM 249019 Removing and installing fuel connection line
Tools
Technical values
Preliminary work
1. Relieve the fuel pressure.
1.1. Pull fuse for fuel pump out of the fuse carrier in the passenger compartment.
1.2. Start the engine and allow to run until it cuts out.
1.3. Re-insert the fuse.
2. Remove engine compartment lid.
-> 557819 Removing and installing engine compartment lid 557819 Removing and Installing Engine Compartment Lid.
3. Disconnect the battery.
4. Remove resonance tube.
-> 247419 Removing and installing resonance tube Service and Repair.
5. Remove intake-air distributor.
-> 244619 Removing and installing intake-air distributor Service and Repair.
5.1. Cover intake port openings with adhesive tape or a cloth.
Removing fuel connection line
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.
Information
- Only work on the fuel system when the engine is cold.
1. Observe safety instructions when working on the fuel system.
1.1. Attach or mount a warning sign in a clearly visible position on the vehicle.
Example of warning sign for naked flames
Overview of fuel-carrying components on the engine:
Overview of DFI fuel system
2. Pull hydraulic line -1- off the oil/water heat exchanger.
2.1. Drain hydraulic fluid (Pentosin) from the reservoir.
2.2. Place a cloth underneath the connection to collect emerging oil.
2.3. Open the spring band clamp and pull off the hydraulic line.
2.4. Close off the connection on the oil/water heat exchanger and hydraulic hose with stoppers -2-.
Hydraulic line on heat exchanger
Information
Specifications for wrench sizes (a/f specifications) for screw heads are described as follows:
- Torx screws: (E.) for external Torx, (T.) for internal Torx.
- Hexagon-head bolts (internal and external hexagon): Wrench size (a/f)
Overview of mounting points for fuel connection line
Fuel connection line
Information
- Ensure everything is clean when working on the fuel system.
- Even the smallest particles of dirt can cause problems and damage to the high-pressure system.
3. Remove fuel line.
3.1. Place a clean cloth underneath the screw points of the fuel line to collect emerging fuel.
3.2. Loosen union nuts (a/f 17) -1 to 3-.
3.3. Unscrew external Torx screw (E10, M6 x 12) -4- on the crankcase clamp.
3.4. Unscrew external Torx screw (E10, M6 x 12) -5- on the clamp on the fuel connection line holder.
4. Turn fuel connection line anti-clockwise to remove it and dispose of the cloth.
5. Close off connection points on the fuel connection line with stoppers.
Installing fuel connection line
WARNING
Leaking fuel supply lines
- Emerging fuel
- Risk of fire
-> Perform leak test. Testing and Inspection
Tool recommendation:
Tool for fuel connection line
Information
- Ensure everything is clean when working on the fuel system.
- Even the smallest particles of dirt can cause problems and damage to the high-pressure system.
1. Remove stoppers from connection points.
2. Fit fuel connection line -6-.
2.1. Lubricate all connection threads and cones with OKS 1700 (Part No. 000.043.207.36).
2.2. Position fuel connection line.
2.3. Tighten union nut (a/f 17) -1- by 2-3 turns with your hand.
2.4. Tighten union nut (a/f 17) -2- by 2-3 turns with your hand.
2.5. Tighten union nut (a/f 17) -3- by 2-3 turns with your hand.
Fuel connection line
3. Fit clamps.
3.1. Fit external Torx screw (E10, M6 x 12) -4- on the clamp.
3.2. Fit external Torx screw (E10, M6 x 12) -5- on the clamp.
3.3. Tighten the screws.
=> Tightening torque: 10 Nm (7.5 ftlb.)
4. Tighten union nuts on the fuel connection line.
4.1. Tighten union nuts in the specified sequence -1 to 3- using the recommended tool.
=> Tightening torque: 20 Nm (15 ftlb.)
Tightening union nuts on fuel line
Information
- Always perform a leak test in the high-pressure area after opening the fuel system. Testing and Inspection
- This is particularly important if components are disassembled and replaced.
- The threaded connections of the fuel lines must be coated with OKS 1700 lubricant (Part no. 000.043.207.36) before being screwed back on again.
- Blow residual fuel out of the lines and high-pressure pump (into a fuel-resistant container or cloth) using compressed air before installation.
- The tightening specifications must be strictly observed.
5. Leak-test the fuel system.
-> 200101 Checking fuel system for leaks Testing and Inspection.
Subsequent work
1. Install intake-air distributor.
-> 244619 Removing and installing intake-air distributor Service and Repair.
2. Install resonance tube. -> 247419 Removing and installing resonance tube - section on "Installing" Service and Repair
-> 247419 Removing and installing resonance tube Service and Repair.
3. Check intake-air distributor for leaks.
-> 244601 Checking intake-air distributor for leaks Testing and Inspection.
4. Check the power-steering fluid level and top up if necessary.
-> 48020150 Checking power-steering fluid level Testing and Inspection.
5. Install engine compartment lid.
-> 557819 Removing and installing engine compartment lid 557819 Removing and Installing Engine Compartment Lid.
6. Connect the battery.
-> 2X00IN02 Work instructions after disconnecting the battery Work Instructions After Disconnecting the Battery.