Procedures

AZ88.00-P-0001-02W Converting Front Bumper
Model 172.4

Check components removed from standard bumper before assembly and replace if damaged.
Pay attention to paint damage.





1 Insert outer left front parking system distance sensor (B8/1) and outer right front parking system distance sensor (B8/6) into front bumper paneling (1) and arrest.
Previously check whether a decoupling ring (transparent silicon ring) is installed properly on the parking distance sensors.





2 Insert mounting rail (3) on right and left into basic carrier (2).
3 Glue basic carrier (2) on right and left into front bumper paneling (1) and arrest.
Rub adhesive strip with blunt object under high pressure to activate glue before removing backing foil. Then directly remove protective foil from basic carrier (2) and press firmly to bonding surface approx. 3 seconds.
The basic carrier (2) should arrest properly in the front bumper paneling (1) on left and right.





4 Insert left front center parking system distance sensor (B8/2) and right front center parking system distance sensor (B8/5) into front bumper paneling (1) and arrest.
Previously check whether a decoupling ring (transparent silicon ring) is installed properly on the parking distance sensors.





5 Insert basic carrier (4) on right and left into front bumper paneling (1) from front and install bearing guides on HCS [SRA] frame segments (4) on outer journals (see arrows).
6 Install HCS [SRA] springs (5) on inner journals.
7 Arrest HCS [SRA] cover (6) on right and left with HCS [SRA] frame segment (4) from outside
Ensure that HCS [SRA] cover (6) is seated correctly on front bumper paneling (1).





8 Insert trim cover (7) into trim cover (8) from rear and bond.
Rub adhesive strip with blunt object under high pressure to activate glue before removing backing foil. Then directly remove protective foil from trim cover (7) and press firmly against bonding surface for approx. 3 seconds.
9 Insert trim (8) on right and left into front bumper paneling (1) from outside and arrest.
The trim covers (8) should arrest properly in the front bumper paneling (1).





10 Insert four lock nuts (10) on right and left into front bumper paneling (1).





11 Insert company logo badge (14) into front bumper paneling (1).
12 Clip right daytime running lamp (E2/3) into bottom right bumper area cover (11) and daytime running lamp (E1/3) into bottom left bumper area cover (12).
13 Screw bottom right bumper area cover (11) and bottom left bumper area cover (12) to front bumper paneling (1) with four 3.5x22 mm bolts (13).





14 Arrest Mercedes star cover (16) on radiator grille (15).
The Mercedes star cover (16) should arrest properly on the radiator grille (15).
15 Clip trims (17) and Mercedes star (18) into Mercedes star cover (16).





16 Insert radiator grille (15) from inside into front bumper paneling (1) and arrest (see circles).
Shown on left side
The radiator grille (15) should arrest properly in the front bumper paneling.
17 Insert inner left front parking system distance sensor (B8/3) and inner right front parking system distance sensor (B8/4) into front bumper paneling (15) and arrest.
Previously check whether a decoupling ring (transparent silicon ring) is installed properly on the parking distance sensors.





18 Insert 4 clips (19) into recesses in front bumper paneling (1).
The clips (19) are asymmetrical and are installed at the top on the smooth side.





19 Insert front bumper bracket (20) on right and left into front bumper paneling (1) and arrest. Install one clip fastener (21) each on front bumper bracket (20).
The wheel arch covers (20) should arrest properly in the front bumper paneling (1).
20 Insert center basic carrier (22) into front bumper paneling (1) and arrest.
The center basic carrier (22) should arrest properly in the front bumper paneling (1).





21 Drill dia. 4.2 mm holes through dome in radiator grille (15) for assembling license plate molding.
Shown on left side
Drill outer or center dome depending on national version. Compare with attachment points of corresponding license plate molding.
22 Screw license plate cover to front bumper paneling (1).





23 Hook check strap (25) on towing eye cover (26) into front bumper paneling (1).
24 Insert towing eye cover (26) into front bumper paneling (1) and arrest.
The towing eye cover (26) should arrest correctly in the front bumper paneling (1).





Vehicles with pedestrian protection sensors

25 Screw left front bumper pedestrian protection sensor (B151/1) and right front bumper pedestrian protection sensor (B151/3) to right and left basic carrier (2) with one sheet metal nut M5 (27) and one bolt M5x20 (28) each.
Notes on avoiding damage to electronic components.





26 Position 4 clip-type fasteners for mounting wiring harness (29) (see circles).
27 Route wiring harness (29) and connect.
28 Arrest frame wiring harness electrical connector and front bumper (X26/38) in right front basic carrier (2).





Vehicles with short range radar

29 Insert left bracket (30) and right bracket (31) into radiator grille (15) and arrest.
Left bracket (30) and right bracket (31) should arrest properly in radiator grille (15).
30 Clip left inner radar sensor, front bumper (A86/1b2) into left bracket (30) and right inner radar sensor, front bumper (A86/1b3) into right bracket (31) and connect.





31 Install center impact absorber (32), right impact absorber (33) and left impact absorber (34) into front bumper paneling (1).





32 Push wheel arch cover (35) on right and left to lug on front bumper paneling (1) (see arrow) and arrest.
The wheel arch covers (35) should arrest properly in the front bumper paneling (1).