246319 Removing and installing DFI high-pressure pump
WM 246319 Removing and installing DFI high-pressure pump
Tools
Technical values
Preliminary work
Information
Before replacing the high-pressure pump if you suspect that it is faulty, check the performance of the fuel pumps in the tank. => 200201 Checking fuel pressure (low pressure) on DFI engines or => 206601 Checking fuel delivery rate (low pressure delivery rate) on DFI engines
1. Remove engine compartment cover at the plenum panel at the middle and left. => 700219 Removing and installing front trim (engine compartment) - section on "Removing"
2. Pull out the fuses for the two fuel pumps. This stops the fuel pumps from starting up when a door is opened.
Information
Component overview
DFI injection system, 3.6 l
Removing high-pressure pump
DANGER
Danger of poisoning from fuels.
-> Gasoline is toxic.
-> Inhaling vapours can cause irritation of the mucous membranes and eyes.
-> It can be carcinogenic. It represents a serious risk to health when inhaled, touched or swallowed over longer periods.
-> Only work on the fuel system in well-ventilated rooms.
-> Wear protective gloves that are fuel-resistant.
-> Wear a breathing mask with active charcoal filter; do not breathe in any fuel vapours.
-> Ensure that there is adequate ventilation and extract all fuel vapours.
-> Before opening the fuel lines or fuel hoses, relieve the fuel pressure.
-> Collect escaping fuel, absorb it if necessary with a suitable binding material and dispose of properly.
-> Pay attention to cleanliness when working on the fuel system.
DANGER
Danger of fire from fuel.
-> Keep clear of ignition sources.
-> Do not smoke.
-> Disconnect battery.
-> Danger of fire due to naked flames and sparks, e.g. during welding or grinding work.
-> Danger of fire due to escaping fuel, e.g. on hot engine components or due to electrostatic charge. Allow engine to cool down.
-> Secure the vehicle, e.g. with a warning sign.
-> Change any clothing soaked with fuel immediately.
-> In case of fire, use CO2 or dry powder fire extinguishers.
CAUTION
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.
CAUTION
Danger of fire from leaking high-pressure lines.
- Fuel can leak out if high-pressure lines are bent or damaged.
- Fuel can leak out if threaded joints are not fitted correctly.
- Fuel can leak out if the tightening specifications are not observed.
-> Never bend high-pressure lines.
-> The high-pressure distribution pipe (rail) or other fuel feed components in the high-pressure area must always be completely removed.
-> Perform a visual inspection to ensure that connection points are undamaged and perfectly clean.
-> Check that threaded joints at connection points are not seized up or corroded. Make sure the thread is not damaged.
-> Fit union nuts on all connection points by hand before screwing in screws or bolts.
-> Pay attention to cleanliness. Remove dirt on the ball/conical joints.
-> Check or inspect connection points for leaks following assembly.
Information
- 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.
- Do not use any sealant containing silicone or silicone spray when the injection system is open. Traces of silicone drawn in by the engine are not combusted and damage the oxygen sensors.
1. Place a cloth under the high-pressure pump. This absorbs leaking fuel.
2. Pull off cable plug on high-pressure sensor -3-. Use the assembly tool T10118 to do this.
View of threaded connections in high-pressure system
3. Release low-pressure line (fuel line) at the union nuts -4 and 7-. To do this, counter at the hexagon and remove line.
4. Release high-pressure line (fuel line) at the union nuts -5 and 6-. To do this, counter at the hexagon and remove line.
5. Unscrew the three screws for the high-pressure pump -1-. For the bottom screw use a thin tool and very carefully press the coolant pipe down. -2-
Mount for high-pressure pump
Accessibility of threaded joint
6. Remove high-pressure pump, turn slightly and release the bottom cable plug for the flow control valve using the assembly tool T10118 or by hand. -arrow-
Cable plug for flow control valve
7. Remove high-pressure pump. => Removing high-pressure pump
Removing high-pressure pump
8. Remove drive tappet -1- and check for signs of damage. Drive tappet has a twist lock on the side. -2-
Drive tappet
Installing high-pressure pump
DANGER
Danger of poisoning from fuels.
-> Gasoline is toxic.
-> Inhaling vapours can cause irritation of the mucous membranes and eyes.
-> It can be carcinogenic. It represents a serious risk to health when inhaled, touched or swallowed over longer periods.
-> Only work on the fuel system in well-ventilated rooms.
-> Wear protective gloves that are fuel-resistant.
-> Wear a breathing mask with active charcoal filter; do not breathe in any fuel vapours.
-> Ensure that there is adequate ventilation and extract all fuel vapours.
-> Before opening the fuel lines or fuel hoses, relieve the fuel pressure.
-> Collect escaping fuel, absorb it if necessary with a suitable binding material and dispose of properly.
-> Pay attention to cleanliness when working on the fuel system.
DANGER
Danger of fire from fuel.
-> Keep clear of ignition sources.
-> Do not smoke.
-> Disconnect battery.
-> Danger of fire due to naked flames and sparks, e.g. during welding or grinding work.
-> Danger of fire due to escaping fuel, e.g. on hot engine components or due to electrostatic charge. Allow engine to cool down.
-> Secure the vehicle, e.g. with a warning sign.
-> Change any clothing soaked with fuel immediately.
-> In case of fire, use CO2 or dry powder fire extinguishers.
CAUTION
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.
CAUTION
Danger of fire from leaking high-pressure lines.
- Fuel can leak out if high-pressure lines are bent or damaged.
- Fuel can leak out if threaded joints are not fitted correctly.
- Fuel can leak out if the tightening specifications are not observed.
-> Never bend high-pressure lines.
-> The high-pressure distribution pipe (rail) or other fuel feed components in the high-pressure area must always be completely removed.
-> Perform a visual inspection to ensure that connection points are undamaged and perfectly clean.
-> Check that threaded joints at connection points are not seized up or corroded. Make sure the thread is not damaged.
-> Fit union nuts on all connection points by hand before screwing in screws or bolts.
-> Pay attention to cleanliness. Remove dirt on the ball/conical joints.
-> Check or inspect connection points for leaks following assembly.
Information
- 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.
- Do not use any sealant containing silicone or silicone spray when the injection system is open. Traces of silicone drawn in by the engine are not combusted and damage the oxygen sensors.
1. Check that the drive tappet -1- is installed correctly. Drive tappet has a twist lock on the side. -2-
Drive tappet
2. Check sealing ring of high-pressure pump for signs of damage and replace if necessary. Avoid shearing off the sealing ring during installation.
3. Place high-pressure pump in installation position => High-pressure pump. Then insert bottom left screw.
High-pressure pump
4. Connect the lower cable plug for the flow control valve. -arrow-
Cable plug for flow control valve
5. Insert the three screws for the high-pressure pump. For the bottom screw use a thin tool and very carefully press the coolant pipe down -2-. Press the high-pressure pump against the resistance of the spring and screw in screws (twist crankshaft if necessary until the drive tappet is at its lowest point). Fit screws -1-. => Tightening torque: 10 Nm (7.5 ftlb.)
Mount for high-pressure pump
Accessibility of threaded joint
6. Position high-pressure line (fuel line) at the union nuts -5 and 6- and tighten. To do this, counter at the hexagon.=> Tightening torque: 22 Nm (16 ftlb.)
7. Position low-pressure line (fuel line) at the union nuts -4 and 7- and tighten. To do this, counter at the hexagon. => Tightening torque: 27 Nm (20 ftlb.)
8. Connect cable plug for high-pressure sensor -3-.
View of threaded connections in high-pressure system
9. Inspect high-pressure system for leaks. => 243001 Checking fuel distribution pipe (fuel rail) on DFI engines for leaks
Subsequent work
1. Fit engine compartment cover at the plenum panel at the middle and left. => 700219 Removing and installing front trim (engine compartment) - section on "Installing"
2. Fit the fuses for the two fuel pumps.