Plenum and Bulkhead Repair Procedure

NOTE:
Water entry into the plenum area is normal. The water must exit through the drain holes at the ends of the plenum cavity. If the drains are clogged or restricted water can leak into the engine compartment area and may leak into the passenger compartment through bulkhead panel seams, harness grommets and other bulkhead openings. The primary object of this procedure is to ensure the proper management of the water entering the plenum. As a secondary precaution, possible leak paths through the bulkhead will be sealed to prevent water entry into the passenger compartment.

1. Following procedures outlined in WSM section 76.16.01 and 76.11.08, remove the hood, engine compartment seal and wiper valence.

2. Refer to TIB 86/03/97/NAS to determine if the HVAC air intake needs to be modified.





3. Install a new windshield washer hose grommet where it passes through the forward plenum wall (Figure 1).

4. Remove adhesive dot on the unused washer hose hole on left-hand side of the forward plenum wall.

5. Install plastic plug (338018) in place of adhesive dot.

6. Locate all unused holes covered with black adhesive dots in the forward plenum wall.

7. Using Kent sealant (LRNA10570) or equivalent, seal all holes. Place sealer on plenum side.





8. On vehicles with front mounted crash sensors (before VIN TA198222 and TA528977), apply LRNA10570 sealant to seal all holes in the plenum floor created by the SRS harness retainers (Figure 2).

9. Seal any other holes between the plenum and the engine compartment.

10. Closely inspect the drain holes at both ends of the plenum.





11. Using a knife or other sharp instrument, carefully remove any excess seam sealer that may be restricting the drain (the drain is a circular hole approximately 25 mm (1 inch) in diameter, see Figure 3). Treat any exposed metal with paint or Dinitrol (RTC7769/25).

NOTE:
Clogged or restricted drain holes, particularly on the right-hand side can cause water to build-up in the plenum cavity under certain conditions such as a torrential rainfall or a car wash. If the water level is high enough, it can leak into the HVAC air intake.

CAUTION:
Whenever using spray sealant, care must be taken to protect the other vehicle surfaces from overspray.

1. Seal the wiper mounting plate to the body and seal all wiper-mounting points with Kent Leak Chek (LRN50087).

NOTE:
Spray sealer directly into the seam. If sealer is applied perpendicular to the joint, the joint will not be covered.

2. Seal between the HVAC air intake and body with Leak Chek spray sealant.

3. Seal around the body to hood hinge mountings with Leak Chek.

4. Apply Leak Chek using an extension tube to seal the following areas of the bulkhead:

^ Pedal box to bulkhead. Right-hand closeout panel to bulkhead.

^ Main harness grommet to bulkhead (right and left sides).

^ Hood release cable pass through.

^ Cruise control vacuum hose pass through.

5. Complete the lower A-pillar repair procedure on the side where water is detected.