Should a vehicle equipped with cast aluminum wheels exhibit a slow leak due to a porous condition existing in the wheel, the wheel can be repaired by using Dow Corning Silastic 732 RTV, p/n 1052366 or equivalent, as described in the following procedure:
1. Remove tire-wheel assembly from vehicle.
2. Locate leaking area by inflating tire to 40 psi and dipping tire-wheel assembly in water bath.
3. If air bubbles are observed, mark leak area and remove tire from wheel.
4. Scuff INSIDE rim surface at leak area with #80 grit paper and clean area with general purpose cleaner, such as 3M #08984.
5. Apply 1/8" thick layer of adhesive/sealant to leak area on INSIDE of rim and allow six hours of drying time.
6. Mount tire on wheel, pressurizing to 40 psi and check for leaks.
Caution must be used when mounting the tire so as not to damage the sealer.
7. Adjust tire pressure to meet placard specification.
8. Balance tire-wheel assembly, using proper coated weights.
9. Water test wheel again.
10. Reinstall tire-wheel assembly on vehicle.
Parts are currently available from GMSPO.
Labor Operation Number: E0420
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.