Fuel Tank: Service and Repair
WM 201019 Removing and installing fuel tank
Technical values
Preliminary work
CAUTION
Heavy components
- Risk of squashing
-> Wear personal protective gear.
-> Get someone to help if necessary.
Information
For safety reasons, the fuel tank should only be removed and installed when empty. For details of how to drain the fuel tank, see -> 2010EN Draining and filling the fuel tank
1. Loosen rear seat and fold it up. Secure to the headrest using a piece of wire if necessary.-> 724819 Removing and installing rear seat - section on "Removing" 724819 Removing and installing rear seat (single-seat look)
2. Loosen reinforcement plate for right seat-belt buckle. To do this, loosen the three fastening screws and twist the plate with the seat-belt buckle to the side. Do not use the fastening screws again.
3. Loosen the right cap (figure shows both) -arrows-. To do this, remove the carpeted floor. Then unscrew the four fastening nuts and remove the cap.
Fastening nuts on caps
4. Disconnect all connections on the right connection unit. Carefully pull off -1, 2 and 3- (place several cloths underneath to absorb the fuel that squirts out). Pull off cable plug.
Fuel supply and connection points at right connection unit
5. Remove carbon canister if necessary. For details of how to remove the carbon canister at its installation position (wheel housing), see -> 202519 Removing and installing carbon canister on DFI engines - section on "Removing" Service and Repair
6. Remove rear axle (spring struts and rear axle housing) and push it aside on a lifting platform (scope of work without disassembling the rear axle further) -> 420500 Removing and installing rear axle housing - section on "Removing" 42051904 Removing and installing rear axle housing
Rear axle and lifting platform
General warning notes
Group 20 - Fuel supply, control
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.
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.
Removing fuel tank
Component overview of degassing tank and fuel tank in the unit
Component overview of fuel tank (diesel - single-pump system)
1. Open the filler flap.
2. Screw the tank cap down. Then remove the rubber sleeve around the tank filler neck, loosen the two fastening screws (M6 x 20) and pull off the ground cable. => Tank filler neck
Tank filler neck
3. Pull the fuel filler neck and degassing tank out of the wheel well and secure with a piece of wire -arrow- (figure shows degassing tank with carbon canister).
Wire securing degassing tank
4. Then, loosen the stone guard on the right side. Remove screws -2-.
Stone guard
5. Remove the line bracket under the stone guard by pressing on the centre plug -arrow-. Replace the line bracket.
Line bracket
6. Remove the centre underbody cover at the left and right on the longitudinal side members. -> 519319 Removing and installing centre cover - section on "Removing" 519319 Removing and Installing Centre Cover
7. Remove rear heat protection plate. To do so, loosen the three speed nuts and two screws.
Heat protection plate
8. Undo the tank attachment band, which runs in the direction of travel -arrows-. Then, position a transmission jack under the tank and secure the tank from falling using a belt. When doing so, make sure that the fuel lines are not damaged.
Tank attachment band
The following exploded drawing shows how the fuel tank is attached to the vehicle floor.
Fuel tank mount
CAUTION
Risk of damaging to fuel lines.
- Lines can become kinked or can crack.
-> Never leave carbon canister hanging freely on the lines.
-> A second person should hold the carbon canister during removal.
9. Get another worker to help you to loosen and remove the remaining restraining straps. Slowly lower the tank with the transmission jack. Also guide the degassing tank in the right wheel housing.
Tank on jack
Installing fuel tank
Component overview of degassing tank and fuel tank in the unit
Component overview of fuel tank (diesel - single-pump system)
The following exploded drawing shows how the fuel tank is attached to the vehicle floor.
Fuel tank mount
Information
- The top left cover must be fitted before the tank is installed.
- When installing the tank and rear axle, make sure that cables and lines are not damaged and are in the correct installation position.
- When introducing the tank into the body, a second person should guide the degassing tank and safeguard it against damage using wire.
1. Raise the tank with a transmission jack. Make sure to secure the tank with a restraining strap to prevent it from falling.
Tank on jack
2. With the help of a second worker, place the tank in installation position. A second person should carefully guide the degassing tank.
Information
- Note direction arrow stamped on the restraining straps and install these in the direction of travel.
3. Attach the lower covers and fit the four restraining straps, which run at right angles to the direction of travel. Make sure that the arrow marking is pointing forward in the direction of travel. Tighten the fastening screws to the specified tightening torque. => Tightening torque: 23 Nm (17 ftlb.)
4. Secure the fuel filler neck and degassing tank again with a piece of wire -arrow-.
Figure shows secured degassing tank (shown here with carbon canister attached)
5. Lower the transmission jack and fit the centre restraining strap. The arrow must be pointing forward. Tighten the fastening screws to the specified torque. => Centre restraining strap on fuel tank => Tightening torque: 23 Nm (17 ftlb.)
Centre restraining strap on fuel tank
6. Fit the heat protection plate for the exhaust system. If the plate is cracked or damaged, it must be replaced. => Heat protection plate
Heat protection plate
7. Fit the underbody panel for the side members at the left and right. -> 519319 Removing and installing centre cover 519319 Removing and Installing Centre Cover
8. Replace the line bracket and fit it on the longitudinal member. Clip in lines. => Line bracket
Line bracket
9. Then fit the stone guard on the right side => Stone guard. Fit nuts -arrows- and tighten to the specified torque. => Tightening torque: 10 Nm (7.5 ftlb.)
Stone guard
10. Fit all connections on the connection unit => Connection unit.
Connection unit
Subsequent work
1. Fit caps. Then tighten the four fastening nuts on each cap. => Tightening torque: 10 Nm (7.5 ftlb.) Refit carpeted floor and fix in place with double-sided adhesive tape.
Fastening nuts on caps
2. Tighten the mounting plates for the seat-belt buckles. Use three new fastening screws for this and tighten. For tightening torques, see -> 692519 Removing and installing rear belt lock 692519 Removing and installing rear belt lock
Fastening screws for retaining brackets for seat-belt buckles
3. Fold rear seat down again.
4. Fit the rear axle (spring struts and rear axle housing). -> 420500 Removing and installing rear axle housing - section on "Installing" 42051904 Removing and installing rear axle housing
Rear axle and lifting platform
5. Fit the carbon canister. -> 202519 Removing and installing carbon canister on DFI engines - section on "Installing" Service and Repair