Removal and installation of fuel tank

A. Model 116 ®1978-1980

Torque wrench double arm, 1/2″ square, 15-65 Nm

e.g. Wille, D-5600 Wuppertal order no. 72 Nm/6

When removing fuel tank, pay attention to safety rules.

1    Disconnect ground connection line on battery.

2    Drain fuel tank. Carefully pump off fuel, so that no residual fuel remains in fuel tank.

3   Loosen suction hose, return hose and vent hose (arrows). Collect residual fuell still in hoses. Close hoses and connections.

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4 Remove trunk mat from trunk.

5 Remove rear wall for fuel tank cover.

6   Unscrew fastening nuts (arrows).

7   Pull out fuel tank slightly and pull off coupler for fuel gauge.

8   Remove fuel tank.

9 Install fuel tank in vice versa sequence and proceed as follows:

a) Glue down both gaskets on underside of fuel tank by means of MB universal glue, part No. 000 989 92 71. For installation, coat both gaskets on sealing surface or bead with sliding compound (talcum, wax or the like).

1     Positive and negative vent line

2    Fuel return line

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b)  Check whether foam rubber strips on fuel tank are tight, glue down with MB universal glue, part No. 000 989 92 71, if required.

c)  Blow out filter (b) and check for damage. Renew sealing ring (a). Tighten fuel filter (68) to 35-43 Nm.

d)  Be sure to mount fuel tank with reinforcing plates and washers provided. Tighten fastening nuts to 17-25 Nm.

e)  Pay attention to correct seat of rubber sleeve on fuel filler neck.

f)   Plug-on coupler for fuel gage and check for func­tion (ground connection line on battery connected).

g)   Renew damaged fuel hoses, h) Check fuel system for leaks.

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1    Cap

2    Seal

3    Rubber sleeve

4    Damping insert

5    Fuel tank

7    Sealing ring

8    Immersion tube indicator (screw-type)

11    Hose clamp

12    Fuel feed line

13    Fuel return line

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Fuel filter

35-43

Immersion tube indicator

Torque wrench double arm, 1/2″ square, 15-65 Nm

e.g. Wille, D-5600 Wuppertal order no. 72 Nm/6

When removing fuel tank, pay attention to safety rules.

1    Disconnect ground connecting line on battery.

2    Drain fuel tank. Carefully pump off fuel, so that no residual fuel remains in fuel tank.

3    Remove trunk floor and intermediate shelf.

4   Pull off coupler (66) for fuel gage.

5    Loosen hose clips (arrows) on vent lines, pull off hoses, tightly close lines and hoses.

6 Loosen hose clamps on front (69) and return line (70), pull off both hoses on fuel tank and catch resi­dual fuel in hose (69). Tightly close hoses and filler neck.

7    Loosen hose clamp (arrow) and pull off vent hose. Close hose and filler neck.

8    Unscrew fastening nuts and remove fuel tank in downward direction.

9 Install fuel tank in vice versa sequence and proceed as follows:

a)   Glue foam rubber strip on fuel tank at level of filler neck crosswise to driving direction.

Note: Never use felt or similar material, since other­wise corrosion damage may result.

b)  Blow out filter (b) and check for damage. Renew sealing ring (a). Install fuel filter (68) and tighten

to 35-43 Nm,

c)   Be sure to install fuel tank with specified rein­forcing plates and washers. Tighten self-locking fasten­ing nuts to 26-34 Nm.

d)  Install vent hose (arrow) between fuel tank and filler neck free of kinks and with a continuous slope toward fuel tank.

The slipped-on O-ring serves for sealing at passage to interior.

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e)   Pay attention to correct seat of sleeves on filler neck.

f)    Renew damaged fuel hoses.

g)  Check operation of fuel gage (ground connection line on battery connected).

h) Check fuel system for leaks.

Fuel tank

Model 123T-sedan

50    Fuel tank

50a   Reinforcing plate

50b Washer

50c  Self-locking nut

51     Vent valve ((uSA)only starting 1981! 55    Expansion tank

60    Filter neck

60a  Sealing sleeve (2 each)

62    Cap

62a  Sealing ring

64    Vent line

64a  Negative vent line

65    Immersion tube indicator 65a  Sealing ring

68    Fuel filter 68a  Sealing ring

69    Feed line

70    Return line 73    Vent sleeve

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C. Model 126 ® starting 1981

Conventional, offset box end wrench 19 mm, shorten according to drawing

When removing fuel tank, pay attention to safety rules.

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1    Disconnect ground connection line on battery.

2    Drain fuel tank. Carefully pump off fuel so that no residual fuel remains in fuel tank.

3    Remove trunk mat.

4    Remove rear wall for fuel tank cover. For this pur­pose, unscrew fastening screws (arrows).

5 Unscrew fuel tank fastening nuts (arrows).

6 Remove suction hose (69) and return flow hose (70) (use shortened box end wrench for return flow hose).

Note: Carefully catch residual fuel from lines. Tightly close lines and fuel tank.

7 Pull hose (64) from vent line and tightly close hose and line.

51 Vent valve

(USA) only starting 1981

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8    Lift fuel tank (50) out of mounting bracket and pull to the rear until coupler (66) for fuel gage can be pulled from immersion tube indicator (65).

9    Remove fuel tank.

Installation

10 Install fuel tank in vice versa sequence while pro­ceeding as follows:

a) Check gasket (71) for tight seat and glue down with MB universal glue, part No. 000 989 92 71, if required. For installation, coat sealing bead with slid­ing compound (talcum, wax or the like).

68 Connection intake hose

71 Gasket

a Connection return flow line

b) Check damping shims (74) for tight seat and glue down with MB universal glue, part No. 000 989 92 71, if required.

147-174&3

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c) Blow out filter (b) and check for damage. Renew sealing ring (a). Tighten fuel filter (68) to 35—43 Nm).

d)  When installing fuel tank, make sure that coupler (66) is plugged on immersion tube indicator (65). Check for function.

e)   Mount fuel tank with reinforcing plates and wash­ers provided. Tighten fastening nuts to 17—25 Nm.

f)   Pay attention to correct seat of sealing sleeve on filler neck, of gaskets between fuel tank and trunk floor and of sealing sleeve on vent line.

g)   Replace copper sealing ring between fuel tank and return flow hose (70).

h) Renew damaged fuel hoses. i) Check fuel system for leaks.

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