WATER LEAKS ON TO AIR CLEANER COVER - SERVICE PROCEDURE

SUBJECT: ENGINE HYDROSTATIC LOCK (WATER INTRUSION)

VEHICLES AFFECTED: 1987 - 1989 MEDIUM DUTY TRUCKS WITH 5.7L/6.OL/7.OL ENGINE AND FIBERGLASS TILT HOOD

During periods of heavy rainfall, water may leak under the hood/cowl seal, around the hood antiflutter bracket and drain on the engine air cleaner cover. This can be witnessed by standing water in the recessions of the air cleaner cover or existence of rust staining. If the air cleaner cover has also become distorted water could drain into the engine intake system and result in engine hydrostatic lock.

Air cleaner distortion may be checked by tightening the air cleaner retaining wing nut, If the wing nut can not be tightened enough to properly hold the air cleaner, then the air cleaner has become distorted.

To eliminate the potential of water dripping on the engine air cleaner cover, the following service procedure may be used:

1. Open hood.

2. Mark location of seal to cowl with masking tape or grease pencil (this will ease reinstallation).

3. With a pair of side cutter pliers placed between the cowl and the bottom of the seal, gently grab and remove each retaining rivet (Figure 1). Repeat this procedure for each rivet. As an alternative, the rivets can be pushed up from the bottom through the cowl.

4. Clean the bottom of the cowl seal and the top of the cowl to insure clean, grease-free surfaces.

5. Install a 1/4" diameter bead of sealer, the total width of the cowl (6 linear feet), directly over the rivet retaining holes, hood anti-flutter bracket and along the edges of the hood anti-flutter bracket (Figure 2).

6. Immediately align the cowl seal and reinstall.

7. With your hand, push the seal down into the sealer.

8. Close hood and secure latches.

IMPORTANT: Do not open the hood or expose the vehicle to moisture for approximately one hour, allowing the sealer time to properly cure.

The following materials will complete one vehicle:

QUANTITY PART NUMBER DESCRIPTION -------- ----------- ----------- 1 1052917 R.T.V. Sealer

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.