Sunroof Water Leak Bulletin

1984-86 FIERO (WITH AD3) Conditions, which contribute to water leaks on 1984 to 1986 Fiero sunroofs, can be repaired by adding drainage holes to the plastic roof outer panel and replacement of hardware nuts at the hinge and latch locations on the glass panel.
This bulletin contains procedures for the addition of holes to the plastic roof outer panel, description and part numbers of new hardware nuts as well as proper sealing patterns for weatherstrips (if weatherstrip replacement is necessary).

The addition of holes provides a water drain system and are to be drilled through the Plastic Roof Outer Panel Only. The holes are to be located in all four (4) corners of the weatherstrip mounting area. Figure 1 shows the location of the holes with the weatherstrip removed for illustrative purposes.

The recommended procedure for adding holes to the roof outer panel is as follows:

1. Remove the sunroof glass assembly from the vehicle and place on a clean work surface.
2. During the following drilling operations, it will be necessary to hold the weatherstrip out of the way to prevent damage. Using a dril and 3/16" drill bit, drill one hole (through the plastic roof outer panel only) in each corner of the weatherstrip cavity as shown above in Figure 1, view A.
3. Reinstall the sunroof glass assembly to the vehicle and water test to insure an acceptable repair.
4. After water testing, remove the sunroof glass and dry the roof inner panel by blowing compressed air through the holes in the roof outer panel. Apply a small amount of GM P/N 1052856 anti-corrosion compound (or equivalent) through the holes in the roof outer panel to protect the metal roof inner panel from corrosion caused by damage done during drilling operations.
If water leaks are noted at the hinge and latch locations, a new hardware nut is now available and provides improved appearance and sealing. The new hardware nut has an integral seal and no longer requires the use of bushings (Figure 2). The nut come in hardware kit part #64245 or is available seperately as part #64430.

Due to the lower profile and improved appearance, the new nut should be used in all locations (hinges and latches) when service operations on sunroofs are performed.

If the sunroof opening weatherstrip is damaged and requires replacement, it is important that the weatherstrip be properly installed and sealed to the tracks and body panels.