Service Procedure
Service ProcedureNote
The following tools are required to complete the service procedure in this bulletin:
- A compact quality drill
- Drill bits that will drill through high strength steel
- A pneumatically powered pop rivet gun that accepts 6.35 mm (1/4 in), 4.76 mm (3/16 in), 3.96 mm (5/32 in) and 3.17 mm (1/8 in) rivets. This tool is available at multiple discount tool providers, such as Harbor Freight Industrial.
1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in SI.
2. Locate the fuel tank strap brackets (1).
Note
The fuel tank strap must be spot welded flush to the floor pan to pass the inspection. Fuel tank straps that have been MIG welded to the floor pan MUST be repaired.
3. Determine if the fuel tank strap brackets are flush against the floor pan. Verify weld type if weld is present.
- If the fuel tank strap brackets are spot welded flush to the floor pan, no further action is required. Lower the vehicle. Refer to illustration. Arrow indicates fuel tank strap bracket to floor pan contact point.
Note
If you cannot determine if there is a gap visually, use a business card or feeler gage to determine if there is a gap between the floor pan and fuel tank strap bracket.
- If you can see a gap between the fuel tank strap bracket and floor pan, the spot weld is missing, proceed to step 4. Refer to illustration. Arrow indicates fuel tank strap bracket to floor pan contact. Illustration show a gap between the fuel tank strap bracket and floor pan.
- If the fuel tank strap bracket is MIG welded (1) to the floor pan, proceed to step 4. Refer to illustration. Arrow indicates MIG welds and fuel tank strap bracket to floor pan contact. MIG welded fuel tank strap brackets require the service repair in this bulletin.
4. Lower the vehicle.
5. Remove rear compartment floor panel trim. Refer to Rear Compartment Floor Panel Trim Replacement in SI.
6. Remove the rear seat. Refer to Rear Seat Replacement (60 Percent Seat) and Rear Seat Replacement (40 Percent Seat) and Rear Seat Cushion Replacement in SI.
7. Raise and support vehicle. Refer to Lifting and Jacking the Vehicle in SI.
8. Remove exhaust front pipe to exhaust rear muffler nuts.
9. Remove rear exhaust pipe from flange.
10. Remove and retain flange gasket.
11. Loosen rear exhaust muffler from suspension points (1, 2, 3).
12. Lower and support the exhaust as required.
13. Remove muffler heat shield (2). Refer to Exhaust Rear Muffler Heat Shield Replacement in SI.
14. Place a jack under the equalizer beam support.
15. Remove the two equalizer beam support bolts.
16. Discard the equalizer beam support bolts.
17. Lower equalizer beam support.
18. Remove jack from equalizer beam support.
19. Place a jack under the fuel tank.
Note
A pry bar is required to close the gap between the tank strap bracket and floor pan. Use a pry bar for steps 20-20.3. Drill the two end holes on the bracket first. Install the bolts and nuts into the two end holes of the tank strap bracket. Refer to steps 21 and 22. Perform steps 20.5-20.7 for the center tank strap bracket hole AFTER the bolts have been installed into the two end tank strap bracket holes.
20. Drill three holes into each tank strap bracket.
1. Center punch the tank strap bracket two end hole locations before drilling the 3mm (1/8 in) pilot holes.
Caution
To increase the useful life of the drill bit, drill the holes into the vehicle body at a low speed. The appropriate drill speed will allow the drill bit to cut into the metal efficiently. The drill bit will remove metal chips or metal shavings from the high strength steel quickly if the appropriate drill speed is used. Ensure the drill used at a low speed. Wear eye protection.
2. Drill two 3mm (1/8 in) pilot holes into the two tank strap bracket end hole locations.
3. Drill two 6.75mm (17/64 in) holes through the two pilot holes.
4. Proceed to steps 21 and 22 to install the bolts and nuts into the two tank strap bracket end hole locations.
5. Center punch the tank strap bracket center hole location before drilling the 3mm (1/8 in) pilot holes.
6. Drill one 3mm (1/8 in) pilot hole into the tank strap bracket center hole location.
7. Drill one 6.75mm (17/64 in) hole into the tank strap center hole location.
21. Apply GM Super Lube(R), to the exterior and interior side of holes.
Note
Step 22 requires two technicians. One technician must sit in the back seat area of the vehicle. Use a ladder to gain access to the vehicle. Install the bolts from inside of the vehicle. Locate the holes and insert the bolts. The technician under the vehicle will install the nuts and tighten the fasteners to 10 Nm (89-lb-in).
22. Secure fuel tank strap bracket with bolts and nuts (1).
Caution
To avoid damaging the brake line, unclip the brake line and secure it away from the work area of the floor pan. Avoid cutting or damaging the brake line with the drill.
Caution
To increase the useful life of the drill bit, drill the holes into the vehicle body at a low speed. The appropriate drill speed will allow the drill bit to cut into the metal efficiently. The drill bit will remove metal chips or metal shavings from the high strength steel quickly if the appropriate drill speed is used. Ensure the drill used at a low speed. Wear eye protection.
23. Drill 10 holes into 5 bar location (1). Refer to illustration for hole locations. Hole locations are marked with a black "X". View from underside of vehicle.
1. Center punch the 5 bar hole locations before drilling the 3mm (1/8 in) pilot holes.
2. Drill ten 3mm (1/8 in) pilot holes into the 5 bar location of the floor pan.
3. Drill ten 6.75mm (17/64 in) holes into the 5 bar location of the floor pan.
24. Apply GM Super Lube(R) to the exterior and interior sides of the 10 holes.
25. Use a ladder to gain access to the rear seat area of the vehicle.
26. Remove material around drilled holes.
27. Install 10 rivets (2) into the 10 holes in the 5 bar location. Install the rivets from inside of the vehicle.
28. Remove jack from fuel tank.
29. Install muffler heat shield. Refer to Exhaust Rear Muffler Heat Shield Replacement in SI.
Caution
Support the exhaust system to install the exhaust pipe and muffler.
30. Install exhaust flange gasket.
31. Install rear exhaust pipe to exhaust flange.
32. Install exhaust front pipe to exhaust rear muffler nuts.
33. Tighten rear exhaust muffler from suspension points (1, 2, 3).
34. Install equalizer beam support. Use new bolts.
35. Tighten equalizer beam support bolts to 100 Nm (74 lb-ft).
36. Lower vehicle.
37. Install the rear seat. Refer to Rear Seat Replacement (60 Percent Seat) and Rear Seat Replacement (40 Percent Seat) and Rear Seat Cushion Replacement in SI.
38. Install rear compartment floor panel trim. Refer to Rear Compartment Floor Panel Trim Replacement in SI.