For 1990-2009 cars

GM vehicles are designed to operate under normal environmental conditions. The design criteria for sealing materials and components takes into consideration the sealing forces required to withstand the natural elements. These specifications do not take into consideration all artificial conditions. High pressure car washes are an example of artificial conditions.

The watertest procedure has been correlated to the natural elements. The watertest procedure will determine the ability of a car to perform under normal operating conditions.

Repairing body waterleaks is a problem requiring the following actions:

• | Proper testing

• | Diagnosis

• | Repair through adjustment of misaligned components and/or application of proven repair materials.

The first step in waterleak diagnosis is finding the conditions under which the leak occurs. The following conditions are examples:

• | The leak is apparent only when the vehicle is parked on an inclined drive.

• | Water is evident in the spare tire compartment.

If the general leak area may be found the exact entry point may be quickly isolated by use of a localized test such as water hose or air hose. If the leak source is not obvious, the generalized testing method using watertest equipment such as a watertest stands should be used. It may be necessary to remove some interior trim panels or components in order to locate and confirm repairs.

Localized testing may be done either using water or air.

1. Begin the test at the base of the suspected area and continue upward slowly until the leak is located.
2. Pinpoint the leak area before any repair is made. Random repair may only temporarily restrict water entry and make future diagnosis and repair more difficult.
3. Continue localized testing in the same general area in order to confirm that all of the leaks have been located.