For 1990-2009 cars

# General Waterleak Diagnosis Guide

Subject: | General Waterleak Diagnosis Guide

Models: | 1997-1999 Buick GL8 (Export China)

| 1997-1999 Chevrolet Trans Sport (Export Europe)

| 1997-2002 Chevrolet Venture

| 1997-2002 Oldsmobile Silhouette

| 1997-2002 Pontiac Trans Sport/Montana

This bulletin contains information on various waterleak conditions. Refer to the following table for a quick reference to the various conditions and the corresponding illustrations.

Condition | Best Described in Condition
--- | ---
Front Floor Wet | 1, 2, 3, 5
Windshield Leak | 4
Mid-Floor Wet | 5, 6, 7
Jack Compartment Full of Clean Water | 8
Jack Compartment Full of Dirty Water | 9, 10
Carpet Wet at Rear | 11, 12, 13
Headliner Wet at Rear | 14

### Condition 1

Some customers may comment on a mildew odor or that the front floor is wet.

### Cause

The water deflector may not be seated properly to the door sheet metal.

### Correction

Seat the water deflector to the door surface at the primary locations. Refer to the arrows in the illustration. If the adhesive surface is dirty and the water deflector needs to be replaced, follow the procedure listed below.

#### Service Procedure

1. The adhesive surface must be clean, dry and free of dirt or contaminants. Clean the door surface (around the perimeter of the water deflector) with one of the cleaners listed below, or an equivalent.
2. Install the water deflector to the inner panel.
3. Pull the harness connectors through their respective holes or slits.
4. Position the outer perimeter of the deflector to the door inner panel by working from the bottom center outboard. Make sure the butyl adhesive is below the drain holes.
5. Using a 50 mm (2 in) wallpaper roller, roll out the butyl adhesive. Start at the bottom center and work outboard, up the right and left sides. A 50 mm (2 in) roller can be purchased at a hardware or wallpaper store.

### Condition 2

Some customers may comment on a mildew odor or that the front floor is wet.

### Cause

There may be a void in the seam sealer at the front of dash.

### Correction

1. Run water over the strut tower. Refer to the arrow in the illustration.
2. Inspect the seam on the inside of the vehicle. Refer to the highlighted line in the illustration.
3. Clean the area with one of the cleaners listed below.
4. Seal the voids with seam sealer. Refer to the list below.

### Condition 3

Some customers may comment on a mildew odor or that the front floor is wet.

### Cause

The wire harness, cables or the HVAC drain that passes through the front of dash may not be sealed properly. Refer to the arrows in the above illustration.

### Correction

Locate the leak by running water down the front of the dash under the hood. Clean the area with one of the cleaners listed below. Seal the area with a seam sealer listed below.

### Condition 4

Some customers may comment on water dripping from the top of the windshield.

### Cause

Important: A large amount water may be able to enter the vehicle through small holes in the body seam sealer.

• | To check for a void in the windshield urethane, run LOW pressure water under the windshield surround molding.

• | If no leak is present, water may be entering from a hole in the body seam sealer at the "C" pillar and then running forward to the windshield. Refer to the arrow in the illustration above. Remove the pitch molding, inspect the patch sealers (from "C" pillar to "D" pillar) for holes, folds, or mis-application. Also, inspect the sheet metal at the top corner of the "C" pillar for holes or visible folds.

### Correction

1. The affected surface must be clean, dry and free of dirt or contaminants. Clean the surface with one of the cleaners listed below, or an equivalent.
2. Fill the pin hole(s) with a clean seam sealer.

### Condition 5

Some customers may comment on a mildew odor or that the front floor/mid-floor is wet.

### Cause

There may be a void in the butyl tape/sealer on the hem flange under the auxiliary seal. Refer to the highlighted line in the illustration above.

### Correction

1. Clean the flange and weatherstrip with one of the cleaners listed below.
2. Apply some weatherstrip adhesive in the weatherstrip retaining cavity and reinstall the weatherstrip to the hem flange.

### Condition 6

Some customers may comment on a mildew odor or the that the mid-floor is wet.

### Cause

The "C" pillar may have a sealer void. Refer to the shaded area in the illustration above.

### Correction

Clean the area with one of the cleaners listed below and seal with a seam sealer listed below.

### Condition 7

Some customers may comment on water pooling up in the corner of the weatherstrip or that the mid-floor is wet.

### Cause

The weatherstrip may allow water to wick in and pool up in the corner. Refer to the arrow in the illustration above.

### Correction

Drill a small 3 mm (1/8 in) hole in the interior surface of the weatherstrip. This will allow the water to drain inside the weatherstrip and exit out the existing holes in the outside of the weatherstrip

### Condition 8

Some customers may comment on clean water in the jack compartment.

### Cause

The power sliding side door cable pass-through grommets may not be seated properly. Refer to the locations shown in the illustration above.

### Correction

Make sure the power sliding side door grommets are seated properly. Seal the perimeter with weatherstrip adhesive as necessary.

### Condition 9

Some customers may comment on dirty water in the jack compartment.

### Cause

There may be a poor seal in the wheelhouse inner to outer sheet metal. Water is thrown off the wheels and forced up through the unsealed joint. Refer to the illustration above.

### Correction

Important: Wear safety glasses and use compressed air to dry the area.

1. Clean the surface area with one of the cleaners listed below.
2. Seal the hole with one of the sealers listed below.

### Condition 10

Some customers may comment on dirty water in the jack compartment.

### Cause

There may be a void in the sealer between the inner and outer wheel house liner. Refer to the highlight in the illustration above.

### Correction

Important: Wear safety glasses and use compressed air to dry the area.

Clean the surface area with one of the cleaners listed below and then seal the hole with one of the sealers listed below.

### Condition 11

Some customers may comment on wet carpet at the rear of the vehicle.

### Cause

The weatherstrip may be turned in on the sides causing poor contact to the liftgate surface. Refer to the arrow in illustration above

### Correction

1. Remove the weatherstrip from the hem flange.
2. Bend the hem flange outboard to ensure a better seal contact.

### Condition 12

Some customers may comment on wet carpet at the rear of the vehicle.

### Cause

The weatherstrip may be turned down at the top causing poor contact to the liftgate surface. Refer to the illustration above

### Correction

Bend the hem flange upright to ensure a better seal.

### Condition 13

Some customers may comment on wet carpet at the rear of the vehicle.

### Cause

The taillight grommet may not be sealed. Refer to the illustration above.

### Correction

Make sure the butyl tape is in place over the taillight grommet.

### Condition 14

Some customers may comment that the headliner is wet at the rear of the vehicle.

### Cause

The wire harness grommet may not be fully seated. Refer to the illustration above.

### Correction

1. Fully seat the rubber grommet.
2. Seal the grommet, if necessary, with weatherstrip adhesive listed below.

### Weatherstrip Adhesive

GM Weatherstrip Adhesive Gel (Black), P/N 12345097 (in Canada, use P/N 10953479)

Parts are currently available from GMSPO.

### Cleaning Solvents

• | 3M® General Purpose Adhesive Cleaner, P/N 08984

• | Dominion Sure Seal, Sure Solve Stock BSS

• | Kent Acrosol™

### Seam Sealer

• | 3M® Clear Auto Sealer, P/N 08551

• | Kent High Tech Seam Sealer Clear, P/N 10200

• | Dominion Sure Seal Heavy Duty Drip Check LSC, Item #9019