For 1990-2009 cars

# T-TOP PANEL WATER LEAK DIAGNOSIS AND REPAIR

#### VEHICLES AFFECTED: 1982-86 'F' Styles

This bulletin is designed to assist Dealer personnel in diagnosing and correcting water leak conditions on cars equipped with the twin lift-off hatch roof option.

Proper diagnosis of the condition is most important. All water testing should be done with the interior garnish mouldings removed on the windshield, lock pillar and lift-off panels. The technician performing the repairs should personally water test the vehicle to determine the specific source of the water leak(s) before beginning repair operations.

Proper water testing equipment can be fabricated by obtaining material locally. An illustration of the proper water test stand (and components) as well as a test location diagram is included in this bulletin. (Figures 1 & 2)

The chart included in this bulletin should be used as an aid in diagnosis. It includes columns for water entry location, the most probable cause(s) of the water leak and which illustration best depicts the correct sealing locations, amounts or patterns. Additional information can be obtained from the body portion of the appropriate Service Manual.

It will not be necessary in all cases to replace weatherstrips. However, in those cases where it is necessary, new weatherstrips (1986 style) are the only parts to be used and MUST BE REPLACED AS A SET (opening and lift-off panel) on the side of the car which is affected.

The new Part Numbers for weatherstrips are as follows:

Weatherstrip, lift-off panel opening on body - 20667535 - Right - 20667534 - Left Weatherstrip, side roof rail on lift-off glass - 20680014

The illustrations contained in this bulletin depict early style (1982-83) components. However, the sealing locations and methods are common on all years. *The RECOMMENDED adhesives and sealing materials are included on those illustrations. (Other adhesives and sealing materials may be comparable, but only the material specified is recommended.) Make sure to protect any interior trim before making any repairs.

Proper lift-off panel and door glass alignments are important to prevent water leaks. If it is determined that the panel and/or door glass require adjustment, refer to the body portion of the Service Manual. Before adjusting the lift-off panel or door glass, make sure that the door to lock pillar wedge plates make contact. To check wedge plate contact, apply a piece of masking tape over the lock pillar wedge plate and close door. If the tape is not torn, additional shim(s) are required and the checking procedure must be performed again after shim(s) are added.

After the necessary repairs are performed, the lift-off panel(s) should be removed and replaced several times to determine if proper alignments are maintained. Retest the unit with the proper water test equipment to ensure a satisfactory repair.

After the final water test, and the vehicle has a satisfactory repair, apply a light coating of paste silicone, GM P/N 992887, with a clean cloth to all weatherstrip surfaces in order to prevent squeaks and prolong weatherstrip life.

Labour Time: 1.0 hour suggested diagnostic time (includes diagnostic water test, garnish moulding removal and installation and final water test to confirm satisfactory repair only).

This time is to be used in addition to the applicable labour operation used for repair. WATERLEAK DIAGNOSIS CHART ------------------------- WATER ENTRY AT PROBABLE CAUSE(S) OF LEAK ILLUSTRATED ON -------------- ------------------------- -------------- - Headliner - between twin - Skips or voids in sealing - Figure #2 lift-off roof panels or of body seams underneath twin at rear of roof. lift-off panel center upper finishing molding.

- Outboard corners of - Skips or voids in the caulking - Figure #3 weatherstrip between or bridge material between the roof sheet metal and weatherstrip and roof sheet weatherstrip. metal.

- Any area between roof - Skips or voids in weatherstrip - Figure #4 portion of weatherstrip adhesive. and retainers or at out- board ends of retainers. - Skips or voids in Secondary - Figure #5 Sealing - Figure #6

- Twin lift-off panel - Skips, voids or improperly - Figure #7 between outer plastic sealed weatherstrip retainers, - Figure #8 support panel and the weatherstrips or sealing strips. sealing strip, weather- strip and/or weather- strip retainer.

- Twin lift-off panel - Skips or voids in urethane - Figure #8 between glass and adhesive outer plastic support panel.

- Door glass to side - Misaligned, misadjusted twin - Figure #9 weatherstrips (especially lift-off panel weatherstrip at the butt joint areas) at butt joints.

- Misaligned, misadjusted door - Refer to Body glass. portion of Service Manual.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.