Fab Fours C3150 User manual

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 1 of 21 C315X_REV_A
SAFETY
Your safety and the safety of others is very important.
▪In order to help you make informed decisions about safety, we have provided
installation instructions and other information.
▪These instructions alert you to potential injury hazards.
▪Please do a job safety analysis before each task to identify potential hazards for
your situation and remove/protect against them.
▪You must use your own good judgment.
▪Read and understand all safety precautions and instructions before installing
this product.
THIS PRODUCT IS FOR OFFROAD USE ONLY. ALL LIABILITY FOR
INSTALLATION AND USE RESTS WITH THE OWNER.
CARELESS INSTALLATION AND OPERATION CAN RESULT IN SERIOUS
INJURY OR EQUIPMENT DAMAGE.
SENSORS FIELD OF VIEW WILL BE ALTERED WITH USE OF THE
REPLACEMENT BUMPER
Injury hazard
Failure to observe these instructions could lead to severe injury or death.
❑Always remove jewelry and wear eye protection.
❑Always use extreme caution when jacking up a vehicle for work. Set
emergency brake and use tire blocks. Locate and use the vehicle
manufacturers designated lifting points. Use jack stands.
❑Always use appropriate and adequate care in lifting components into place.
❑Always ensure components will remain secure during installation and
operation.
❑Always wear safety glasses when installing this kit. A drilling operation will
cause flying metal chips. Flying chips can cause serious eye injury.
❑Always use extreme caution when drilling on a vehicle. Thoroughly inspect
the area to be drilled (on both sides of material) prior to drilling, and
relocate any objects that may be damaged.
❑Always use extreme caution when cutting and trimming during fitting.
❑Always tighten all nuts and bolts securely per installation instructions.
❑Always route electrical cables carefully. Avoid moving parts, components
that become hot and rough or sharp edges.
❑Always insulate and protect all exposed wiring and electrical terminals.
❑Always perform regular inspections and maintenance on mounts and
related hardware.

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 2 of 21 C315X_REV_A
I. Overview
Congratulations on your new purchase of the industries’ best and most
stylish front bumper available for the 2015 GMC Heavy Duty! This
bumper has been engineered for strength while keeping the weight
down.
Your front bumper is designed in 3D from digitized data, CNC laser cut,
fabricated, and powder coated… all in the U.S.A.
Enjoy the fit and finish of a quality GMC HD Front Bumper from Fab
Fours, Inc.

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 3 of 21 C315X_REV_A
Parts List
•C315X replacement bumper
•A315X brackets (20679 and 20680)
•A305X-HW fastener kit
•Fog lights and turn signals (61737 and 61738)
•Resistors (61675)
•Welded bolt strips (20296)
•Instruction Manual
Tools Required
•Socket Wrench with Extension (Ratcheting wrenches may also be
convenient)
•7mm, 10mm, 15mm, 18mm, 19mm, 3/4 Sockets and Box End
Wrenches
•Flat head screw drivers
•Floor jack, jack stands, and/or a wood block.
•9/16 drill bit w/ drill
II. Removal of OEM Bumper
Note: Save all OEM parts until installation is complete!
A. Open hood and locate the twelve push pins on radiator cover.
Using a flat head screw driver or similar tool, pull the head of the
push pins up, remove push pin and lift radiator cover off. This will
allow access to top grill bolts (Ref. Figure 1).
Figure 1

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 4 of 21 C315X_REV_A
B. Remove the fasteners connecting the grill to the frame with a
10mm socket. Four bolts are located at the top of the grill, two on
each side (Ref. Figure 2a-b). There are multiple clips holding the grill
to the vehicle.
Figure 2a-bolts on LH side Figure 2b-grill removed-bolt locations RH
Figure 2c- example of clip holding grill

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 5 of 21 C315X_REV_A
C. Disconnect electrical harness (Ref. Figure 3a) from vehicle and
remove tow hooks. Tow hooks are mounted with one cross bolt
through the side and a bolt through the bottom of the frame (Ref.
Figure 3b).
Figure 3a (TOW HOOK & OEM MOUNTING BRACKET)
D. Remove bolts connecting bumper to mounting bracket (Ref.
Figure 3a circles). There are two bolts on each side which require a
socket wrench with an extension to easily reach from top and
bottom. (Ref. Figure 3a-b). Carefully pull bumper away from vehicle.

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 6 of 21 C315X_REV_A
Figure 3b (BOLT ACCESS FOR TOP BOLT ON MOUNTING BRACKET)
E. Remove the fasteners connecting the OEM mounting bracket
to the frame. Using a socket/wrench remove four bolts from the front
of bracket connected to the bumper. Repeat process on each side of
vehicle.
F. Remove OEM electrical harness from bumper. Disconnect
harness from fog lights and sensors. Pop out the three plastic clips
holding fog lights to fog light housing and carefully pull away. The
plastic clips are indicated by a circle. Unbolt bumper support frames
as necessary to more easily access sensors (Ref. Figure 6).
Figure 6

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 7 of 21 C315X_REV_A
NOTE: PARKING SENSORS ARE EXTREMELY DELICATE AND
MUST BE HANDLED WITH CARE! Do NOT touch or shift the
clear rubber grommet that surrounds the sensor face.
G. Remove OEM electrical harness from bumper. Disconnect
harnesses from fog lights and sensors. Sensors can be
disconnected from housing by depressing the plastic clip indicated
by the red square (ref. Figure 8a).
Figure 8
H. CAREFULLY remove sensors from plastic housing by gently pulling the
top and bottom tabs, indicated by blue circles (Ref. Figure 8a), away as
sensor is pulled out. Do not push on front of sensor as this will damage the
membrane. Place sensors face up in a safe location.
I. Remove plastic housing from OEM bumper by depressing the four
plastic tabs around the inside and pushing housing out. All sensor
housings will have to be placed into the Fab Fours bumper in the same
location as they were removed from OEM bumper. (e.g. Outer right sensor
clip must go into the outer right sensor hole in the Fab Fours bumper.)

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 8 of 21 C315X_REV_A
III. Pre-Installation
NOTE: PLEASE READ THE ENTIRE MANUAL BEFORE
ATEMPTING INSTALLATION!
Ignoring these steps will increase your probability of scratching
the vehicle and damaging the sensors during product
installation.
A. Remove the bumper from the shipping carton. Lay all items out on a
blanket to prevent damage to the powder coating.
B. Place sensor housing in Fab Four bumper replicating the orientation
seen in the images below. The housings should slide in freely and not be
forced as this may compress sensor and cause false readings after
installation. After assuring sensors work in current orientation, epoxy
should be applied to the housing on inside of bumper and allowed to dry.
C. For sensor installation, run sensor harness under winch tray. Reverse
steps G through I in previous section, making sure that the clear plastic
grommet around front end of sensor is on properly and sensors appear
centered in their housings. Final installation of sensors on driver side
should appear as follows with passenger side sensors mirrored. (Ref.
Figures 9a-f)

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 9 of 21 C315X_REV_A

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 10 of 21 C315X_REV_A
Install the provided Fab Fours fog lights using the provided
hardware kit. The wiring diagram for the fog lights can be found in
section V.

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 11 of 21 C315X_REV_A
Figure 7
•Optional: If installing winch and roller fairlead into bumper, do it
after sensors have been installed. Follow the winch
manufacturer’s instructions for installation.
IV. Front Bumper Installation
A. Mount bracket to truck frame. Two bolts pass through the
sides of the frame. One bolt passes through the bottom of the frame
(Ref. 8a-b). Mount on both sides. If holes on the side of frame are out
of tolerance then enlarge hole with 9/16 drill as needed on side of
frame.
Figure 8a Figure 8b
B. Mount bracket to bumper. With the help of at least two others,

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 12 of 21 C315X_REV_A
and possibly a floor jack to support the center of the bumper, lift the
Fab Fours bumper into place.
C. Insert the bolt strips from the inside facing out and tighten. Do
Not Fully Tighten, Hand Tighten Only!
D. Align the bumper side to side and top to bottom to ensure a
perfect fit to the truck. Allow clearance to all painted surfaces, this is
to allow for frame flex.
E. Fully tighten all fasteners between bumper and bracket.
F. Enjoy your New Front Replacement Bumper from Fab Fours!

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 13 of 21 C315X_REV_A
V. Fog Light and Turn Signal Wiring
1. Disconnect the battery of your truck.
2. With a flathead screwdriver, remove pins attaching upper
shroud. Remove the shroud.
3. Using a 10mm wrench, remove the 4 bolts attaching the grill
and remove grill by pulling forward.
4. After removing the grill, remove the front 10mm bolt and two
7mm bolts located on the inside and outside of the wheel arch.
Remove under headlight trim.
5. Remove the remaining 10mm bolts on the top of the headlight
pod and two bolts on the front of the pod that are now exposed.
Headlight should now slide forward.
6. To completely remove, disconnect the headlight wiring
harness.
7. Using the provided hardware, splice the wires using the wiring
guide below.

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 14 of 21 C315X_REV_A
FAB FOURS TURN INDICATOR WIRING
WHITE WIRE = GROUND
BROWN WIRE = RUNNING
RED WIRE = TURN
FAB FOURS FOG LIGHT WIRING
WHITE WIRE = GROUND
BLACK WIRE = POWER
*Note: For customers that are going from LED to our LED lights
you should not need to use the provided resistors*
*For customers that are going from Halogen to our LED lights then
you may need to use the provided resistors on our turn indicators;
please wire the resistors between your power and ground wire*
*Use a multi-meter or test light to determine the correct location for
each wire

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 15 of 21 C315X_REV_A
8. Connect headlight and wires and fog light/turn signal
wires.
9. Reattach headlight pods to truck
10. Install turn indicators into the plastic light insert using
three self-tapping screws as shown below.
Figure 12a
11. Install the light inserts with turn indicators into the cutout
in the bumper. Use the ¾” length ¼” stainless steel
button head, ¼” washers and hex nuts to fasten the insert
through the holes shown below.

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 16 of 21 C315X_REV_A
Figure 13a
12. Install the Fab Fours fog lights into the mounting brackets
as shown below using the #8 button head screws,
washers, and hex nuts.
Figure 14a

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 17 of 21 C315X_REV_A
13. 13. Install the fog light and bracket into the bumper
using the remaining two holes.
14. 14. Install turn indicators into the plastic light insert
using three self-tapping screws as shown below.
Figure 12a
15. Install the light inserts with turn indicators into the cutout
in the bumper. Use the ¾” length ¼” stainless steel
button head, ¼” washers and hex nuts to fasten the insert
through the holes shown below.
Figure 13a

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 18 of 21 C315X_REV_A
16. Install the Fab Fours fog lights into the mounting brackets
as shown below using the #8 button head screws,
washers, and hex nuts.
Figure 14a
17. Install the fog light and bracket into the bumper using the
remaining two holes

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 19 of 21 C315X_REV_A
VI. Maintenance/Care
❑Periodically check and tighten all fasteners.
❑Stripped, fractured, or bent bolts or nuts need to be replaced.
❑After washing of the vehicle make sure to fully dry all surfaces

Installation Instructions
15 GMC HD Premium Front Bumper
Product Number: C3150, C3151, C3152
Application: 2015-2019 GMC HD
Copyright 2008 Fab Fours, Inc. Page 20 of 21 C315X_REV_A
APPENDIX A. Troubleshooting Vehicle Sensors
•Start with a general inspection of the sensor fitment. Check that both
the sensors and the sensor clips are fully secure and the sensors are
properly centered in the housing.
•Confirm plastic housing is in the correct mounting holes. Misplaced
sensor housings could compress sensor and give false readings or
faults.
•Use a clean microfiber to wipe the front face of the sensor as dirt or
debris can cause issues.
•Inspect connection. Be sure that the sensor is firmly seated into the
harness.
•Run through several start cycles (i.e. fully turn the vehicle on and off).
•Finally, disconnect the battery to reset the sensors.
If sensors still do not work, sensors may have been
damaged during the installation process. Take vehicle
to a certified dealership.